values

package
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 Go to latest Published: Apr 12, 2026 License: Apache-2.0 Imports: 22 Imported by: 0

Documentation

Overview

Package values implements all Scheme runtime value types.

The package provides the complete R7RS value system:

Numeric Tower (R7RS 6.2.1)

All numeric types implement the Number interface for uniform arithmetic.

Core Types

I/O Ports (R7RS 6.13)

Port types implement Port, InputPort, OutputPort, and related interfaces:

Concurrency (SRFI-18+)

Singletons

Use Void for the absence of a value and EOFObject for end-of-file. EmptyList is the empty list sentinel.

Package values provides Scheme runtime value types.

Index

Constants

View Source 
const (
	PrefixCharacter    = `#\`
	PrefixSyntax       = `#'`
	PrefixDirective    = `#!`
	PrefixBox          = `#&`
	PrefixPrimitive    = `#%`
	PrefixBlockComment = `#|`
	PrefixLineComment  = `;`

	SpecialEOF  = PrefixDirective + `eof`
	SpecialVoid = PrefixDirective + `void`
)

Prefix constants for Scheme value representations.

View Source 
const DefaultBigFloatPrecision = 256

DefaultBigFloatPrecision is the default precision for BigFloat values.

Variables

View Source 
var (

	// FalseValue is the singleton false boolean.
	FalseValue = newBoolean(false)
	// TrueValue is the singleton true boolean.
	TrueValue = newBoolean(true)
)
View Source 
var (
	SymbolMutexNotOwned  = NewSymbol("not-owned")
	SymbolMutexAbandoned = NewSymbol("abandoned")
)

Mutex state symbol singletons.

StateValue() returns these instead of allocating fresh symbols on each call. Same process-global vs per-VM identity subtlety as the thread state symbols — see the doc comment on SymbolThreadNew in thread.go for details.

View Source 
var (
	SymbolThreadNew        = NewSymbol("new")
	SymbolThreadRunnable   = NewSymbol("runnable")
	SymbolThreadBlocked    = NewSymbol("blocked")
	SymbolThreadTerminated = NewSymbol("terminated")
	SymbolThreadUnknown    = NewSymbol("unknown")
	SymbolPrimordial       = NewSymbol("primordial")
)

Thread state symbol singletons.

StateSymbol() and PrimCurrentThread return these package-level singletons instead of allocating fresh symbols on each call. This guarantees self-consistency: (eq? (thread-state t) (thread-state t)) → #t.

However, these are process-global pointers, not per-VM interned symbols. Reader-interned 'new (created via the parser gate) lives in the per-VM Namespace intern table and is a different pointer. Therefore: 

(eq? (thread-state t) (thread-state t))  → #t  (same singleton)
(eq? (thread-state t) 'new)              → #f  (singleton ≠ interned)
(equal? (thread-state t) 'new)           → #t  (string comparison)

SRFI-18 defines thread states as symbols but does not mandate eq? identity against reader-interned symbols, so this is conformant. The equal? path works because Symbol.EqualTo compares .Key strings.

To make eq? work against reader-interned symbols, these singletons would need to participate in the per-VM intern table. That requires either:

  • Lazily interning on first use (needs access to an environment)
  • Registering these symbols during Engine initialization

The values/ package cannot import environment/ (it's lower in the dependency graph), so this would need to be driven from engine.go or registry/. This is deferred until there is a concrete need.

Functions

func BigIntegerEqualsFloat added in v1.3.0 

func BigIntegerEqualsFloat(bi *BigInteger, f *Float) bool

BigIntegerEqualsFloat compares a BigInteger to a Float. Returns true only if the float exactly represents the BigInteger value.

func BooleanToBool added in v1.4.0 

func BooleanToBool(b *Boolean) bool

BooleanToBool converts a Scheme *Boolean to a Go bool value.

func DisplayValueToString 

func DisplayValueToString(v Value) string

DisplayValueToString writes a Scheme value to a string for display with cycle detection. Unlike WriteValueToString, strings are printed without quotes and characters without #\.

func EqualTo 

func EqualTo(a, b Value) bool

func ExactInteger 

func ExactInteger(v Value) (int64, bool)

ExactInteger extracts an exact integer from a Scheme value. Returns the int64 value and true if the value is an exact integer that fits in int64. Returns 0 and false otherwise.

Accepts:

  • *Integer: direct int64 value
  • *BigInteger: if it fits in int64
  • *Rational: if denominator is 1 and numerator fits in int64

R7RS defines exact integers to include rationals like 2/1 that are mathematically integers. Call sites should check for non-negativity if required (e.g., for indexes).

func IntegerEqualsFloat added in v1.3.0 

func IntegerEqualsFloat(i *Integer, f *Float) bool

IntegerEqualsFloat compares an exact integer to an inexact float. Returns true only if the float exactly represents the integer value.

R7RS §6.2.5: Numeric equality must not lose precision. An exact integer and an inexact float are equal only if the float exactly represents the integer's value.

func IsEmptyList 

func IsEmptyList(v Value) bool

IsEmptyList returns true if the value is the empty list. Returns false for nil values. For Tuple types, delegates to their IsEmptyList method.

func IsList 

func IsList(v Value) bool

IsList returns true if the value is a proper list. A proper list is either EmptyList or a chain of pairs ending with EmptyList. Returns false for nil, improper lists (dotted pairs), and non-list values.

func IsVoid 

func IsVoid(v Value) bool

IsVoid returns true if the value represents the absence of a meaningful result.

Void, EmptyList, and nil Semantics

The value system distinguishes three "absence/empty" concepts:

  • Void (voidType{} singleton): no meaningful result (e.g., set!, display). Canonical check: values.IsVoid(v) — handles both nil and the Void singleton.

  • EmptyList (emptyListType{} singleton): the empty list () — a valid first-class Scheme value. Implements Tuple but not *Pair. Canonical check: values.IsEmptyList(v) — handles nil safely (returns false).

  • Go nil (nil interface): uninitialized / absent in Go — not a Scheme value. IsVoid(nil) returns true; IsEmptyList(nil) returns false.

Anti-patterns to avoid:

  • v == values.EmptyList or v != values.EmptyList → use values.IsEmptyList(v)
  • v == values.Void → use values.IsVoid(v)
  • v == nil || values.IsVoid(v) → redundant; values.IsVoid(v) handles nil

Note: typed nil pointers (e.g., var p *Pair = nil) are handled by the type's IsVoid() method, which checks for nil receiver.

func Must added in v1.1.0 

func Must(v Value, err error)

Must panics if err is non-nil or v is not EmptyList. Designed for use with ForEach on lists guaranteed to be proper: 

Must(p.ForEach(ctx, func(...) error { ... }))

func NumberToComplex128 added in v1.5.0 

func NumberToComplex128(n Number) complex128

NumberToComplex128 converts any Number to complex128. BigFloat and BigComplex values are reduced to float64/complex128 precision. This is intended for paths where precision loss is acceptable, such as IEEE 754 Inf/NaN guards and inexact complex arithmetic in extensions.

func NumberToFloat64 added in v1.5.0 

func NumberToFloat64(n Number) float64

NumberToFloat64 converts any Number to a best-effort float64 approximation. BigInteger, BigFloat, and Rational values lose precision in the conversion. For Complex inputs, only the real component is returned; for BigComplex, the real part is converted via toBigFloat. Callers must not rely on this function to reject complex values.

func SchemeTypeName added in v1.10.3 

func SchemeTypeName(v Value) string

SchemeTypeName returns the Scheme-facing type name for a value. Used in error messages so users see "integer" instead of "*values.Integer".

func ValidateByteValue added in v1.3.0 

func ValidateByteValue(v *Integer, name string, desc string) error

ValidateByteValue checks that an integer is in the byte range [0, 255]. Returns a wrapped werr.ErrNotAByte error if the value is out of range.

func ValueToBool added in v1.4.0 

func ValueToBool(b Value) bool

ValueToBool converts a value into a Go bool using Scheme semantics. In Scheme, only #f is false; everything else (including 0, "", '()) is true.

func WriteSharedValueToString 

func WriteSharedValueToString(v Value) string

WriteSharedValueToString writes a Scheme value to a string with shared structure detection. Uses WriteModeWriteShared: datum labels for all multiply-referenced objects. R7RS §6.13.3: write-shared outputs datum labels for all shared structure.

func WriteValueToString 

func WriteValueToString(v Value) string

WriteValueToString writes a Scheme value to a string with cycle detection. Uses WriteModeWrite: datum labels only for circular references. R7RS §6.13.3: write outputs datum labels only for objects that are part of a cycle.

Types

type AbandonedMutexException 

type AbandonedMutexException struct {
	Mutex Value // *Mutex, but avoid circular import
}

AbandonedMutexException is raised when a mutex owner terminates

func (*AbandonedMutexException) Error 

func (p *AbandonedMutexException) Error() string

type AtomicBox 

type AtomicBox struct {
	// contains filtered or unexported fields
}

AtomicBox provides atomic operations on a Value This uses atomic.Value from the standard library

func NewAtomicBox 

func NewAtomicBox(initial Value) *AtomicBox

NewAtomicBox creates a new AtomicBox with the given initial value

func (*AtomicBox) CompareAndSwap 

func (p *AtomicBox) CompareAndSwap(ol, nw Value) bool

CompareAndSwap atomically compares and swaps if current equals old Returns true if the swap was performed

func (*AtomicBox) EqualTo 

func (p *AtomicBox) EqualTo(v Value) bool

EqualTo returns true if the atomics are the same object.

func (*AtomicBox) ID 

func (p *AtomicBox) ID() uint64

ID returns the AtomicBox's unique identifier

func (*AtomicBox) IsVoid 

func (p *AtomicBox) IsVoid() bool

IsVoid returns true if the atomic is nil.

func (*AtomicBox) Load 

func (p *AtomicBox) Load() Value

Load atomically loads and returns the value

func (*AtomicBox) SchemeString 

func (p *AtomicBox) SchemeString() string

SchemeString returns the Scheme representation of the atomic.

func (*AtomicBox) Store 

func (p *AtomicBox) Store(v Value)

Store atomically stores the value

func (*AtomicBox) Swap 

func (p *AtomicBox) Swap(v Value) Value

Swap atomically stores new and returns the old value

type AtomicInt64 

type AtomicInt64 struct {
	// contains filtered or unexported fields
}

AtomicInt64 provides atomic operations on int64 values This is more efficient than AtomicBox for integer operations

func NewAtomicInt64 

func NewAtomicInt64(initial int64) *AtomicInt64

NewAtomicInt64 creates a new AtomicInt64 with the given initial value

func (*AtomicInt64) Add 

func (p *AtomicInt64) Add(delta int64) int64

Add atomically adds delta and returns the new value

func (*AtomicInt64) CompareAndSwap 

func (p *AtomicInt64) CompareAndSwap(ol, nw int64) bool

CompareAndSwap atomically compares and swaps Returns true if the swap was performed

func (*AtomicInt64) EqualTo 

func (p *AtomicInt64) EqualTo(v Value) bool

EqualTo returns true if the atomics are the same object.

func (*AtomicInt64) ID 

func (p *AtomicInt64) ID() uint64

ID returns the AtomicInt64's unique identifier

func (*AtomicInt64) IsVoid 

func (p *AtomicInt64) IsVoid() bool

IsVoid returns true if the atomic int64 is nil.

func (*AtomicInt64) Load 

func (p *AtomicInt64) Load() int64

Load atomically loads and returns the value

func (*AtomicInt64) SchemeString 

func (p *AtomicInt64) SchemeString() string

SchemeString returns the Scheme representation of the atomic int64.

func (*AtomicInt64) Store 

func (p *AtomicInt64) Store(v int64)

Store atomically stores the value

func (*AtomicInt64) Swap 

func (p *AtomicInt64) Swap(nw int64) int64

Swap atomically stores new and returns the old value

type BigComplex 

type BigComplex struct {
	// contains filtered or unexported fields
}

BigComplex represents an arbitrary-precision complex number. The real and imaginary parts can be *BigInteger, *Rational (exact), or *BigFloat (inexact).

R7RS §6.2.1: Complex numbers are part of the numeric tower hierarchy: 

number ⊃ complex ⊃ real ⊃ rational ⊃ integer

R7RS §6.2.2: BigComplex is exact if both parts are BigInteger or Rational, inexact if either part is BigFloat. Operations follow exactness contagion rules.

func NewBigComplex 

func NewBigComplex(rel, iam Number) *BigComplex

NewBigComplex creates a new BigComplex from real and imaginary parts. Parts must be *BigInteger, *Rational, or *BigFloat. Other types will panic.

func NewBigComplexFromBigFloats 

func NewBigComplexFromBigFloats(rel, iam *BigFloat) *BigComplex

NewBigComplexFromBigFloats creates an inexact BigComplex from BigFloat parts.

func NewBigComplexFromBigIntegers 

func NewBigComplexFromBigIntegers(rel, iam *BigInteger) *BigComplex

NewBigComplexFromBigIntegers creates an exact BigComplex from BigInteger parts.

func (*BigComplex) Abs added in v1.1.0 

func (p *BigComplex) Abs() Number

Abs returns the magnitude of this BigComplex as a Number.

R7RS §6.2.6: For complex numbers, abs returns the magnitude.

func (*BigComplex) Add 

func (p *BigComplex) Add(o Number) Number

R7RS §6.2.6: The + procedure returns the sum of its arguments. R7RS §6.2.2 Exactness: exact + exact = exact, exact + inexact = inexact. Inexactness is contagious per R7RS §6.2.2.

func (*BigComplex) Compare 

func (p *BigComplex) Compare(o Number) int

Compare compares this BigComplex with another number by real parts.

R7RS §6.2.6: Numeric comparisons use mathematical value. For complex numbers, we compare real parts only (matching Complex behavior).

func (*BigComplex) Conjugate 

func (p *BigComplex) Conjugate() *BigComplex

Conjugate returns the complex conjugate (a-bi for a+bi).

func (*BigComplex) Divide 

func (p *BigComplex) Divide(o Number) (Number, error)

Divide returns the quotient of this BigComplex and another number. Complex division: (a+bi)/(c+di) = ((ac+bd) + (bc-ad)i) / (c²+d²)

R7RS §6.2.6: The / procedure returns the quotient of its arguments. R7RS §6.2.2 Exactness: exact / exact = exact, exact / inexact = inexact.

func (*BigComplex) EqualTo 

func (p *BigComplex) EqualTo(o Value) bool

EqualTo returns true if both complex numbers have equal real and imaginary parts.

R7RS §6.2.6: The = procedure compares numerical values for equality.

func (*BigComplex) HashCode added in v1.5.0 

func (p *BigComplex) HashCode() uint64

HashCode returns a hash of the complex value. Hashes real and imaginary parts independently via hashInexactNumeric and combines them with a multiplicative mixing constant. Uses the same combining formula as Complex.HashCode for cross-type consistency: when BigComplex.EqualTo(*Complex) holds, both produce equal hashes.

func (*BigComplex) Imag 

func (p *BigComplex) Imag() Number

Imag returns the imaginary part of the complex number.

func (*BigComplex) ImagAsBigFloat 

func (p *BigComplex) ImagAsBigFloat() *BigFloat

ImagAsBigFloat returns the imaginary part converted to BigFloat for calculations.

func (*BigComplex) ImagPart added in v1.1.0 

func (p *BigComplex) ImagPart() Number

ImagPart returns the imaginary part of this complex number as a Number.

R7RS §6.2.6: imag-part returns the imaginary part of a complex number.

func (*BigComplex) IsExact 

func (p *BigComplex) IsExact() bool

IsExact returns true if both parts are exact (BigInteger or Rational).

R7RS §6.2.2: A complex number is exact if both real and imaginary parts are exact.

func (*BigComplex) IsFinite added in v1.1.0 

func (p *BigComplex) IsFinite() bool

IsFinite returns true if both real and imaginary parts are finite.

R7RS §6.2.6: finite? returns #t if neither part is Inf or NaN.

func (*BigComplex) IsInteger added in v1.1.0 

func (p *BigComplex) IsInteger() bool

IsInteger returns true if the imaginary part is zero and the real part is an integer.

R7RS §6.2.6: integer? returns #t for complex numbers with zero imaginary part whose real part is an integer.

func (*BigComplex) IsNaN added in v1.1.0 

func (p *BigComplex) IsNaN() bool

IsNaN returns true if either real or imaginary part is NaN.

R7RS §6.2.6: nan? returns #t for complex numbers with a NaN component.

func (*BigComplex) IsRational added in v1.1.0 

func (p *BigComplex) IsRational() bool

IsRational returns true if this BigComplex is a real, finite number.

R7RS §6.2.6: rational? returns #t for finite real numbers. Inf and NaN are not rational, even when the imaginary part is zero.

func (*BigComplex) IsReal 

func (p *BigComplex) IsReal() bool

IsReal returns true if the imaginary part is zero.

func (*BigComplex) IsVoid 

func (p *BigComplex) IsVoid() bool

IsVoid returns true if this BigComplex is nil.

func (*BigComplex) IsZero 

func (p *BigComplex) IsZero() bool

IsZero returns true if both real and imaginary parts are zero.

func (*BigComplex) Kind added in v1.5.0 

func (p *BigComplex) Kind() NumericKind

Kind returns the numeric kind for dispatch table indexing.

func (*BigComplex) LessThan 

func (p *BigComplex) LessThan(o Number) bool

LessThan compares the real parts of complex numbers. Following R7RS, < is not mathematically defined for complex numbers, but we follow the existing Complex.LessThan pattern of comparing real parts.

func (*BigComplex) Magnitude 

func (p *BigComplex) Magnitude() *BigFloat

Magnitude returns the absolute value (modulus) of the complex number. |a+bi| = sqrt(a² + b²)

func (*BigComplex) Multiply 

func (p *BigComplex) Multiply(o Number) Number

Multiply returns the product of this BigComplex and another number. Complex multiplication: (a+bi)(c+di) = (ac-bd) + (ad+bc)i

R7RS §6.2.6: The * procedure returns the product of its arguments. R7RS §6.2.2 Exactness: exact * exact = exact, exact * inexact = inexact.

func (*BigComplex) Negate 

func (p *BigComplex) Negate() Number

Negate returns the negation of this BigComplex.

func (*BigComplex) Phase 

func (p *BigComplex) Phase() *BigFloat

Phase returns the phase (argument) of the complex number in radians. Uses atan2(imag, real).

func (*BigComplex) Real 

func (p *BigComplex) Real() Number

Real returns the real part of the complex number.

func (*BigComplex) RealAsBigFloat 

func (p *BigComplex) RealAsBigFloat() *BigFloat

RealAsBigFloat returns the real part converted to BigFloat for calculations.

func (*BigComplex) RealPart added in v1.1.0 

func (p *BigComplex) RealPart() Number

RealPart returns the real part of this complex number as a Number.

R7RS §6.2.6: real-part returns the real part of a complex number.

func (*BigComplex) SchemeString 

func (p *BigComplex) SchemeString() string

SchemeString returns the Scheme representation of this BigComplex.

func (*BigComplex) Subtract 

func (p *BigComplex) Subtract(o Number) Number

Subtract returns the difference of this BigComplex and another number.

R7RS §6.2.6: The - procedure returns the difference of its arguments. R7RS §6.2.2 Exactness: exact - exact = exact, exact - inexact = inexact.

func (*BigComplex) ToExact 

func (p *BigComplex) ToExact() (Number, error)

ToExact converts this BigComplex to an exact representation.

R7RS §6.2.6: exact returns an exact representation of its argument. If already exact, returns itself. Otherwise converts BigFloat parts to BigInteger by truncating (may lose precision).

func (*BigComplex) ToInexact 

func (p *BigComplex) ToInexact() Number

ToInexact converts this BigComplex to an inexact representation.

R7RS §6.2.6: inexact returns an inexact representation of its argument. Converts BigInteger parts to BigFloat.

type BigFloat 

type BigFloat struct {
	// contains filtered or unexported fields
}

BigFloat represents an arbitrary-precision floating-point number. Created with the #m prefix in Scheme (e.g., #m3.14159265358979323846).

big.Float natively supports ±Inf via SetInf/IsInf. NaN has no native big.Float representation (operations that produce NaN under IEEE 754 panic with big.ErrNaN instead), so NaN is tracked via an out-of-band flag.

Invariant: when nan is true, value MUST be a valid (zero-valued) *big.Float, never nil, to prevent nil-pointer panics.

func NewBigFloat 

func NewBigFloat(v *big.Float) *BigFloat

NewBigFloat creates a new BigFloat from a big.Float.

func NewBigFloatFromFloat64 

func NewBigFloatFromFloat64(v float64) *BigFloat

NewBigFloatFromFloat64 creates a new BigFloat from a float64.

func NewBigFloatFromString 

func NewBigFloatFromString(s string) *BigFloat

NewBigFloatFromString creates a new BigFloat from a string. Returns nil if the string is not a valid number.

func NewBigFloatNaN added in v1.5.0 

func NewBigFloatNaN() *BigFloat

NewBigFloatNaN creates a new BigFloat representing NaN.

func (*BigFloat) Abs 

func (p *BigFloat) Abs() Number

Abs returns the absolute value of this BigFloat.

func (*BigFloat) Add 

func (p *BigFloat) Add(o Number) Number

R7RS §6.2.6: The + procedure returns the sum of its arguments. R7RS §6.2.2 Exactness: inexact + inexact = inexact, exact + inexact = inexact. Inexactness is contagious per R7RS §6.2.2.

func (*BigFloat) BigFloatValue 

func (p *BigFloat) BigFloatValue() *big.Float

BigFloatValue returns the underlying big.Float value.

func (*BigFloat) Compare 

func (p *BigFloat) Compare(o Number) int

Compare compares this BigFloat with another number. Returns 0 for NaN operands (NaN has no valid ordering).

func (*BigFloat) Divide 

func (p *BigFloat) Divide(o Number) (Number, error)

Divide returns the quotient of this BigFloat and another number.

func (*BigFloat) EqualTo 

func (p *BigFloat) EqualTo(o Value) bool

EqualTo returns true if this BigFloat equals another value. NaN is not equal to anything, including itself (IEEE 754).

func (*BigFloat) Float64 

func (p *BigFloat) Float64() float64

Float64 returns the value as float64 (may lose precision).

func (*BigFloat) HashCode added in v1.3.0 

func (p *BigFloat) HashCode() uint64

HashCode returns a hash code for this BigFloat. For Inf and NaN, delegates to float64 bit pattern matching Float.HashCode, ensuring Float and BigFloat produce identical hashes for equal values.

Note: NaN != NaN (IEEE 754), so two NaN BigFloats are never EqualTo each other. A NaN key stored in a hashtable is therefore unretrievable — the Hashable contract is not violated, but NaN is not a useful hashtable key.

func (*BigFloat) IsExact 

func (p *BigFloat) IsExact() bool

IsExact returns false since BigFloat is always inexact.

func (*BigFloat) IsFinite added in v1.1.0 

func (p *BigFloat) IsFinite() bool

IsFinite returns true if this BigFloat holds a finite value.

R7RS §6.2.6: finite? returns #t for finite numbers.

func (*BigFloat) IsInteger added in v1.1.0 

func (p *BigFloat) IsInteger() bool

IsInteger returns true if this BigFloat represents an integer value.

R7RS §6.2.6: integer? returns #t for inexact integers.

func (*BigFloat) IsNaN added in v1.1.0 

func (p *BigFloat) IsNaN() bool

IsNaN returns true if this BigFloat holds NaN.

R7RS §6.2.6: nan? returns #t for NaN values.

func (*BigFloat) IsNegative 

func (p *BigFloat) IsNegative() bool

IsNegative returns true if this BigFloat is negative. NaN has no sign and returns false.

func (*BigFloat) IsPositive 

func (p *BigFloat) IsPositive() bool

IsPositive returns true if this BigFloat is positive. NaN has no sign and returns false.

func (*BigFloat) IsRational added in v1.1.0 

func (p *BigFloat) IsRational() bool

IsRational returns true if this BigFloat holds a finite value.

R7RS §6.2.6: rational? returns #t for all finite real numbers. Inf and NaN are not rational.

func (*BigFloat) IsVoid 

func (p *BigFloat) IsVoid() bool

IsVoid returns true if this BigFloat is nil.

func (*BigFloat) IsZero 

func (p *BigFloat) IsZero() bool

IsZero returns true if this BigFloat is zero.

func (*BigFloat) Kind added in v1.5.0 

func (p *BigFloat) Kind() NumericKind

Kind returns the numeric kind for dispatch table indexing.

func (*BigFloat) LessThan 

func (p *BigFloat) LessThan(o Number) bool

LessThan returns true if this BigFloat is less than another number.

func (*BigFloat) Multiply 

func (p *BigFloat) Multiply(o Number) Number

Multiply returns the product of this BigFloat and another number.

func (*BigFloat) Negate 

func (p *BigFloat) Negate() Number

Negate returns the negation of this BigFloat.

func (*BigFloat) SchemeString 

func (p *BigFloat) SchemeString() string

SchemeString returns the Scheme representation of this BigFloat.

R7RS §6.2.6: Inexact integers must include a decimal point to distinguish them from exact integers. big.Float.Text('g', -1) drops ".0" for integer values, so we append it when neither '.' nor 'e'/'E' is present.

func (*BigFloat) Sign added in v1.1.0 

func (p *BigFloat) Sign() int

Sign returns -1 if negative, 0 if zero, or 1 if positive. NaN returns 0 (NaN has no sign).

func (*BigFloat) Subtract 

func (p *BigFloat) Subtract(o Number) Number

Subtract returns the difference of this BigFloat and another number.

R7RS §6.2.6: The - procedure returns the difference of its arguments. R7RS §6.2.2 Exactness: inexact - inexact = inexact, exact - inexact = inexact.

func (*BigFloat) ToExact 

func (p *BigFloat) ToExact() (Number, error)

ToExact converts this BigFloat to an exact Rational.

R7RS §6.2.6: (exact +inf.0) and (exact +nan.0) are errors.

func (*BigFloat) ToInexact 

func (p *BigFloat) ToInexact() Number

ToInexact returns this BigFloat unchanged since it's already inexact.

type BigInteger 

type BigInteger struct {
	// contains filtered or unexported fields
}

BigInteger represents an arbitrary-precision integer. Created with the #z prefix in Scheme (e.g., #z12345678901234567890).

R7RS §6.2.1: Integers are exact numbers in the numeric tower hierarchy: 

number ⊃ complex ⊃ real ⊃ rational ⊃ integer

R7RS §6.2.2: BigInteger is always exact. Operations on exact numbers produce exact results when mathematically well-defined.

R7RS §6.2.3: Implementations may support arbitrarily large exact integers. BigInteger provides this capability using Go's math/big.Int.

Precision Preservation

BigInteger operations with Float preserve precision by promoting to BigFloat for comparison and arithmetic. This avoids precision loss from converting large BigIntegers to float64 (which has only 53 bits of mantissa precision).

Prior to M5 fix, BigIntegers with >53 significant bits would be truncated when compared with Float, causing incorrect comparison results. For example, comparing 2^53+1 with 2^53.0 would incorrectly report equality after both were converted to the same float64 value.

The fix promotes both operands to BigFloat (arbitrary precision), ensuring correct comparisons and arithmetic while preserving R7RS exactness contagion (exact + inexact → inexact).

func NewBigInteger 

func NewBigInteger(v *big.Int) *BigInteger

NewBigInteger creates a new BigInteger from a big.Int.

func NewBigIntegerFromInt64 

func NewBigIntegerFromInt64(v int64) *BigInteger

NewBigIntegerFromInt64 creates a new BigInteger from an int64.

func NewBigIntegerFromString 

func NewBigIntegerFromString(s string, base int) *BigInteger

NewBigIntegerFromString creates a new BigInteger from a string. Returns nil if the string is not a valid integer.

func (*BigInteger) Abs 

func (p *BigInteger) Abs() Number

Abs returns the absolute value of this BigInteger.

func (*BigInteger) Add 

func (p *BigInteger) Add(o Number) Number

R7RS §6.2.6: The + procedure returns the sum of its arguments. R7RS §6.2.2 Exactness: exact + exact = exact (BigInteger), exact + inexact = inexact (Float/Complex). Inexactness is contagious per R7RS §6.2.2.

func (*BigInteger) BigInt 

func (p *BigInteger) BigInt() *big.Int

BigInt returns the underlying big.Int value.

func (*BigInteger) Compare 

func (p *BigInteger) Compare(o Number) int

Compare compares this BigInteger with another number.

R7RS §6.2.6: Numeric comparisons use mathematical value regardless of exactness. Returns -1, 0, or 1 for less than, equal, or greater than.

func (*BigInteger) Divide 

func (p *BigInteger) Divide(o Number) (Number, error)

Divide returns the quotient of this BigInteger and another number.

R7RS §6.2.6: The / procedure returns the quotient of its arguments. For exact arguments, / may return a non-integer (Rational) when the mathematical result is not an integer. Returns BigInteger only when the division is exact (remainder is zero).

R7RS §6.2.2 Exactness: exact / exact = exact (BigInteger or Rational), exact / inexact = inexact (Float or Complex).

func (*BigInteger) EqualTo 

func (p *BigInteger) EqualTo(o Value) bool

EqualTo returns true if this BigInteger equals another value.

R7RS §6.2.6: The = procedure compares numerical values for equality. BigInteger also compares equal to Integer when values match.

func (*BigInteger) HashCode 

func (p *BigInteger) HashCode() uint64

HashCode returns a hash of the big integer value. Uses the canonical exact-family hash so that Integer, BigInteger, and Rational produce identical hashes for equal values.

func (*BigInteger) Int64 

func (p *BigInteger) Int64() int64

Int64 returns the value as int64 (may overflow for large values).

func (*BigInteger) IsExact 

func (p *BigInteger) IsExact() bool

IsExact returns true as BigInteger is always exact.

R7RS §6.2.2: Integers (including BigInteger) are always exact.

func (*BigInteger) IsFinite added in v1.1.0 

func (p *BigInteger) IsFinite() bool

IsFinite returns true since integers are always finite.

R7RS §6.2.6: finite? returns #t for all exact numbers.

func (*BigInteger) IsInteger added in v1.1.0 

func (p *BigInteger) IsInteger() bool

IsInteger returns true since BigInteger is always an integer.

R7RS §6.2.6: integer? returns #t for exact integers.

func (*BigInteger) IsNaN added in v1.1.0 

func (p *BigInteger) IsNaN() bool

IsNaN returns false since integers are never NaN.

R7RS §6.2.6: nan? returns #f for exact numbers.

func (*BigInteger) IsNegative 

func (p *BigInteger) IsNegative() bool

IsNegative returns true if this BigInteger is negative.

func (*BigInteger) IsPositive 

func (p *BigInteger) IsPositive() bool

IsPositive returns true if this BigInteger is positive.

func (*BigInteger) IsRational added in v1.1.0 

func (p *BigInteger) IsRational() bool

IsRational returns true since integers are a subset of rationals.

R7RS §6.2.6: rational? returns #t for all real finite numbers.

func (*BigInteger) IsVoid 

func (p *BigInteger) IsVoid() bool

IsVoid returns true if this BigInteger is nil.

func (*BigInteger) IsZero 

func (p *BigInteger) IsZero() bool

IsZero returns true if this BigInteger is zero.

func (*BigInteger) Kind added in v1.5.0 

func (p *BigInteger) Kind() NumericKind

Add returns the sum of this BigInteger and another number.

Kind returns the numeric kind for dispatch table indexing.

func (*BigInteger) LessThan 

func (p *BigInteger) LessThan(o Number) bool

LessThan returns true if this BigInteger is less than another number.

R7RS §6.2.6: The < procedure returns #t if its arguments are monotonically increasing. Comparison across numeric types uses mathematical value.

func (*BigInteger) Multiply 

func (p *BigInteger) Multiply(o Number) Number

Multiply returns the product of this BigInteger and another number.

R7RS §6.2.6: The * procedure returns the product of its arguments. R7RS §6.2.2 Exactness: exact * exact = exact, exact * inexact = inexact. Exception: Exact zero dominates—(* 0 x) may return exact 0 even when x is inexact. Zero is an exact value when the result is mathematically unambiguous. This implementation follows Chez Scheme's behavior.

func (*BigInteger) Negate 

func (p *BigInteger) Negate() Number

Negate returns the negation of this BigInteger.

func (*BigInteger) SchemeString 

func (p *BigInteger) SchemeString() string

SchemeString returns the Scheme representation of this BigInteger.

func (*BigInteger) Sign added in v1.1.0 

func (p *BigInteger) Sign() int

Sign returns -1 if negative, 0 if zero, or 1 if positive.

func (*BigInteger) Subtract 

func (p *BigInteger) Subtract(o Number) Number

Subtract returns the difference of this BigInteger and another number.

R7RS §6.2.6: The - procedure returns the difference of its arguments. R7RS §6.2.2 Exactness: exact - exact = exact, exact - inexact = inexact.

func (*BigInteger) ToExact 

func (p *BigInteger) ToExact() (Number, error)

ToExact returns this BigInteger as an exact number.

R7RS §6.2.6: exact returns an exact representation of its argument. Since BigInteger is already exact, it returns itself.

func (*BigInteger) ToInexact 

func (p *BigInteger) ToInexact() Number

ToInexact returns this BigInteger converted to an inexact float.

R7RS §6.2.6: inexact returns an inexact representation of its argument. Converts to Float (float64), which may lose precision for large values.

R7RS §6.2.3: The inexact representation may have limited precision, but the conversion should be as close as practical.

PRECISION NOTE: For BigIntegers with more than 53 significant bits, precision is lost when converting to float64 (IEEE 754 binary64 has only 53 bits of mantissa precision). This is compliant with R7RS which allows inexact to be approximate.

type BinaryInputPort 

type BinaryInputPort struct {
	// contains filtered or unexported fields
}

BinaryInputPort represents a Scheme binary input port.

func NewBinaryInputPort 

func NewBinaryInputPort(rdr *bufio.Reader) *BinaryInputPort

NewBinaryInputPort creates a new binary input port wrapping the given rdr.

func NewBinaryInputPortFromReader 

func NewBinaryInputPortFromReader(reader io.Reader) *BinaryInputPort

NewBinaryInputPortFromReader creates a new input port reading from the given byte slice.

func (*BinaryInputPort) Close 

func (p *BinaryInputPort) Close() error

Close marks the port as closed and, if a closer was provided, closes the underlying stream. Close is idempotent.

func (*BinaryInputPort) Datum 

func (p *BinaryInputPort) Datum() io.Reader

Datum returns the underlying io.Reader.

func (*BinaryInputPort) EqualTo 

func (p *BinaryInputPort) EqualTo(v Value) bool

EqualTo returns true if v is a port with the same kind and datum identity. This works because Go's any equality checks both dynamic type and value, so two ports sharing a kind but using different backing types (e.g., *bufio.Writer vs *bytes.Buffer) will never compare equal.

func (*BinaryInputPort) IsClosed 

func (p *BinaryInputPort) IsClosed() bool

IsClosed returns true if the port has been closed.

func (*BinaryInputPort) IsVoid 

func (p *BinaryInputPort) IsVoid() bool

IsVoid returns true if the port is nil.

func (*BinaryInputPort) Read 

func (p *BinaryInputPort) Read(bs []byte) (int, error)

func (*BinaryInputPort) ReadByte 

func (p *BinaryInputPort) ReadByte() (byte, error)

func (*BinaryInputPort) SchemeString 

func (p *BinaryInputPort) SchemeString() string

SchemeString returns the Scheme external representation of the port.

func (*BinaryInputPort) UnreadByte 

func (p *BinaryInputPort) UnreadByte() error

type BinaryOutputPort 

type BinaryOutputPort struct {
	// contains filtered or unexported fields
}

BinaryOutputPort represents a Scheme binary output port.

func NewBinaryOutputPortFromWriter 

func NewBinaryOutputPortFromWriter(writer io.Writer) *BinaryOutputPort

NewBinaryOutputPortFromWriter creates a new input port reading from the given byte slice.

func (*BinaryOutputPort) Close 

func (p *BinaryOutputPort) Close() error

Close flushes buffered data and closes the underlying stream.

func (*BinaryOutputPort) Datum 

func (p *BinaryOutputPort) Datum() io.Writer

Datum returns the underlying io.Writer.

func (*BinaryOutputPort) EqualTo 

func (p *BinaryOutputPort) EqualTo(v Value) bool

EqualTo returns true if v is a port with the same kind and datum identity. This works because Go's any equality checks both dynamic type and value, so two ports sharing a kind but using different backing types (e.g., *bufio.Writer vs *bytes.Buffer) will never compare equal.

func (*BinaryOutputPort) Flush 

func (p *BinaryOutputPort) Flush() error

Flush flushes the port's buffer.

func (*BinaryOutputPort) IsClosed 

func (p *BinaryOutputPort) IsClosed() bool

IsClosed returns true if the port has been closed.

func (*BinaryOutputPort) IsVoid 

func (p *BinaryOutputPort) IsVoid() bool

IsVoid returns true if the port is nil.

func (*BinaryOutputPort) SchemeString 

func (p *BinaryOutputPort) SchemeString() string

SchemeString returns the Scheme external representation of the port.

func (*BinaryOutputPort) Write 

func (p *BinaryOutputPort) Write(bs []byte) (int, error)

Write writes bytes to the port.

func (*BinaryOutputPort) WriteByte 

func (p *BinaryOutputPort) WriteByte(b byte) error

WriteByte writes a single byte to the port.

type BinaryReader 

type BinaryReader interface {
	InputPort
	ReadByte() (byte, error)
	UnreadByte() error
}

BinaryReader represents a binary input port capable of byte-level I/O.

R7RS §6.13.2: Binary input ports support read-u8, peek-u8, read-bytevector, etc.

type BinaryWriter 

type BinaryWriter interface {
	OutputPort
	WriteByte(byte) error
}

BinaryWriter represents a binary output port capable of byte-level I/O.

R7RS §6.13.3: Binary output ports support write-u8, write-bytevector, etc.

type Boolean 

type Boolean struct {
	Value bool
}

Boolean represents a Scheme boolean value.

func BoolToBoolean added in v1.4.0 

func BoolToBoolean(b bool) *Boolean

BoolToBoolean converts a Go bool to a Scheme boolean value.

func ValueToBoolean added in v1.4.0 

func ValueToBoolean(b Value) *Boolean

ValueToBoolean converts a value into a Scheme *Boolean using Scheme semantics.

func (*Boolean) Datum 

func (p *Boolean) Datum() bool

Datum returns the underlying boolean value.

func (*Boolean) EqualTo 

func (p *Boolean) EqualTo(v Value) bool

EqualTo returns true if the values are equal booleans.

func (*Boolean) HashCode 

func (p *Boolean) HashCode() uint64

HashCode returns a hash of the boolean value.

func (*Boolean) IsVoid 

func (p *Boolean) IsVoid() bool

IsVoid returns true if the boolean is nil.

func (*Boolean) SchemeString 

func (p *Boolean) SchemeString() string

SchemeString returns the Scheme representation of the boolean.

type Box 

type Box struct {
	Value Value
}

Box represents a mutable Scheme box (container).

func NewBox 

func NewBox(v Value) *Box

NewBox creates a new box containing the given value.

func (*Box) Datum 

func (p *Box) Datum() Value

Datum returns the boxed value.

func (*Box) EqualTo 

func (p *Box) EqualTo(v Value) bool

EqualTo returns true if the boxes contain equal values.

func (*Box) IsVoid 

func (p *Box) IsVoid() bool

IsVoid returns true if the box is nil.

func (*Box) SchemeString 

func (p *Box) SchemeString() string

SchemeString returns the Scheme representation of the box.

func (*Box) Unbox 

func (p *Box) Unbox() Value

Unbox returns the boxed value.

type Byte 

type Byte struct {
	Value uint8
}

Byte represents a Scheme byte value (0-255).

func NewByte 

func NewByte(v uint8) *Byte

NewByte creates a new byte value.

func (*Byte) Datum 

func (p *Byte) Datum() uint8

Datum returns the underlying byte value.

func (*Byte) EqualTo 

func (p *Byte) EqualTo(v Value) bool

EqualTo returns true if the bytes have equal values.

func (*Byte) HashCode 

func (p *Byte) HashCode() uint64

HashCode returns a hash of the byte value.

func (*Byte) IsVoid 

func (p *Byte) IsVoid() bool

IsVoid returns true if the byte is nil.

func (*Byte) SchemeString 

func (p *Byte) SchemeString() string

SchemeString returns the Scheme representation of the byte.

type ByteVector 

type ByteVector []*Byte

ByteVector represents a Scheme bytevector.

func NewByteVector 

func NewByteVector(vs ...*Byte) *ByteVector

NewByteVector creates a new bytevector from byte values.

func NewByteVectorFromBytes 

func NewByteVectorFromBytes(vs ...byte) *ByteVector

func NewByteVectorFromIntegers 

func NewByteVectorFromIntegers(vs ...*Integer) (*ByteVector, error)

NewByteVectorFromIntegers creates a new bytevector from integer values. Each integer must be in the range [0, 255] per R7RS §6.4.

func (*ByteVector) AsBytes 

func (p *ByteVector) AsBytes(is ...int) []byte

AsBytes converts the bytevector to a Go byte slice. The starti and endi parameters specify the range of bytes to include. If starti is negative, it is treated as 0. If endi is greater than the length of the bytevector or non-positive, it is treated as the length of the bytevector. If starti is greater than endi, it is treated as equal to endi.

func (*ByteVector) AsList 

func (p *ByteVector) AsList() Tuple

AsList converts the vector to a proper list (linked list of pairs). Returns void (nil Pair) if the vector is void. Returns EmptyList if the vector is empty. Otherwise returns a newly constructed list containing the vector's elements.

func (*ByteVector) Datum 

func (p *ByteVector) Datum() []*Byte

Datum returns the underlying byte slice.

func (*ByteVector) EqualTo 

func (p *ByteVector) EqualTo(v Value) bool

EqualTo returns true if the bytevectors have equal contents.

func (*ByteVector) Get 

func (p *ByteVector) Get(i int) Value

func (*ByteVector) IsVoid 

func (p *ByteVector) IsVoid() bool

IsVoid returns true if the bytevector is nil.

func (*ByteVector) Length 

func (p *ByteVector) Length() int

func (*ByteVector) SchemeString 

func (p *ByteVector) SchemeString() string

SchemeString returns the Scheme representation of the bytevector.

func (*ByteVector) Set 

func (p *ByteVector) Set(i int, value Value) error

Set sets the element at the specified index to the given value. ByteVectors are always mutable, so this never returns an error from immutability. Returns an error if the value is not a Byte.

type ByteVectorBufferedOutputPort added in v1.5.0 

type ByteVectorBufferedOutputPort struct {
	// contains filtered or unexported fields
}

ByteVectorBufferedOutputPort represents a Scheme output port writing to memory.

func NewByteVectorBufferedOutputPort added in v1.5.0 

func NewByteVectorBufferedOutputPort() *ByteVectorBufferedOutputPort

NewByteVectorBufferedOutputPort creates a new in-memory bytevector output port.

func NewByteVectorBufferedOutputPortFromBuffer added in v1.5.0 

func NewByteVectorBufferedOutputPortFromBuffer(buf *bytes.Buffer) *ByteVectorBufferedOutputPort

NewByteVectorBufferedOutputPortFromBuffer creates a new in-memory bytevector output port.

func (*ByteVectorBufferedOutputPort) Close added in v1.5.0 

func (p *ByteVectorBufferedOutputPort) Close() error

Close marks the port as closed and, if a closer was provided, closes the underlying stream. Close is idempotent.

func (*ByteVectorBufferedOutputPort) Datum added in v1.5.0 

func (p *ByteVectorBufferedOutputPort) Datum() *bytes.Buffer

Datum returns the underlying bytes.Buffer.

func (*ByteVectorBufferedOutputPort) EqualTo added in v1.5.0 

func (p *ByteVectorBufferedOutputPort) EqualTo(v Value) bool

EqualTo returns true if v is a port with the same kind and datum identity. This works because Go's any equality checks both dynamic type and value, so two ports sharing a kind but using different backing types (e.g., *bufio.Writer vs *bytes.Buffer) will never compare equal.

func (*ByteVectorBufferedOutputPort) Flush added in v1.5.0 

func (p *ByteVectorBufferedOutputPort) Flush() error

func (*ByteVectorBufferedOutputPort) IsClosed added in v1.5.0 

func (p *ByteVectorBufferedOutputPort) IsClosed() bool

IsClosed returns true if the port has been closed.

func (*ByteVectorBufferedOutputPort) IsVoid added in v1.5.0 

func (p *ByteVectorBufferedOutputPort) IsVoid() bool

IsVoid returns true if the port is nil.

func (*ByteVectorBufferedOutputPort) ReadByteVector added in v1.5.0 

func (p *ByteVectorBufferedOutputPort) ReadByteVector() (*ByteVector, error)

func (*ByteVectorBufferedOutputPort) SchemeString added in v1.5.0 

func (p *ByteVectorBufferedOutputPort) SchemeString() string

SchemeString returns the Scheme external representation of the port.

func (*ByteVectorBufferedOutputPort) Write added in v1.5.0 

func (p *ByteVectorBufferedOutputPort) Write(bs []byte) (int, error)

func (*ByteVectorBufferedOutputPort) WriteByte added in v1.5.0 

func (p *ByteVectorBufferedOutputPort) WriteByte(b byte) error

type ByteVectorExtractor 

type ByteVectorExtractor interface {
	ReadByteVector() (*ByteVector, error)
}

ByteVectorExtractor represents a port that can extract its accumulated bytes.

type ByteVectorInputOutputPort 

type ByteVectorInputOutputPort struct {
	// contains filtered or unexported fields
}

ByteVectorInputOutputPort represents a Scheme output port writing to memory.

func NewByteVectorInputOutputPort 

func NewByteVectorInputOutputPort() *ByteVectorInputOutputPort

NewByteVectorInputOutputPort creates a new in-memory bytevector output port.

func NewByteVectorInputOutputPortFromBuffer 

func NewByteVectorInputOutputPortFromBuffer(buf *bytes.Buffer) *ByteVectorInputOutputPort

NewByteVectorInputOutputPortFromBuffer creates a new in-memory bytevector output port.

func (*ByteVectorInputOutputPort) Close 

func (p *ByteVectorInputOutputPort) Close() error

Close marks the port as closed and, if a closer was provided, closes the underlying stream. Close is idempotent.

func (*ByteVectorInputOutputPort) Datum 

func (p *ByteVectorInputOutputPort) Datum() *bytes.Buffer

Datum returns the underlying bytes.Buffer.

func (*ByteVectorInputOutputPort) EqualTo 

func (p *ByteVectorInputOutputPort) EqualTo(v Value) bool

EqualTo returns true if v is a port with the same kind and datum identity. This works because Go's any equality checks both dynamic type and value, so two ports sharing a kind but using different backing types (e.g., *bufio.Writer vs *bytes.Buffer) will never compare equal.

func (*ByteVectorInputOutputPort) Flush 

func (p *ByteVectorInputOutputPort) Flush() error

func (*ByteVectorInputOutputPort) IsClosed 

func (p *ByteVectorInputOutputPort) IsClosed() bool

IsClosed returns true if the port has been closed.

func (*ByteVectorInputOutputPort) IsVoid 

func (p *ByteVectorInputOutputPort) IsVoid() bool

IsVoid returns true if the port is nil.

func (*ByteVectorInputOutputPort) Read 

func (p *ByteVectorInputOutputPort) Read(bs []byte) (int, error)

func (*ByteVectorInputOutputPort) ReadByte 

func (p *ByteVectorInputOutputPort) ReadByte() (byte, error)

func (*ByteVectorInputOutputPort) ReadByteVector 

func (p *ByteVectorInputOutputPort) ReadByteVector() (*ByteVector, error)

func (*ByteVectorInputOutputPort) SchemeString 

func (p *ByteVectorInputOutputPort) SchemeString() string

SchemeString returns the Scheme external representation of the port.

func (*ByteVectorInputOutputPort) UnreadByte 

func (p *ByteVectorInputOutputPort) UnreadByte() error

UnreadByte unreads the last byte read, allowing it to be read again.

func (*ByteVectorInputOutputPort) Write 

func (p *ByteVectorInputOutputPort) Write(bs []byte) (int, error)

func (*ByteVectorInputOutputPort) WriteByte 

func (p *ByteVectorInputOutputPort) WriteByte(b byte) error

type ByteVectorInputPort 

type ByteVectorInputPort struct {
	// contains filtered or unexported fields
}

ByteVectorInputPort represents a Scheme input port reading from a byte slice.

func NewByteVectorInputPortFromReader 

func NewByteVectorInputPortFromReader(reader io.Reader) *ByteVectorInputPort

NewByteVectorInputPortFromReader creates a new input port reading from the given byte slice.

func (*ByteVectorInputPort) Close 

func (p *ByteVectorInputPort) Close() error

Close marks the port as closed and, if a closer was provided, closes the underlying stream. Close is idempotent.

func (*ByteVectorInputPort) Datum 

func (p *ByteVectorInputPort) Datum() *bufio.Reader

Datum returns the underlying bytes.Reader.

func (*ByteVectorInputPort) EqualTo 

func (p *ByteVectorInputPort) EqualTo(v Value) bool

EqualTo returns true if v is a port with the same kind and datum identity. This works because Go's any equality checks both dynamic type and value, so two ports sharing a kind but using different backing types (e.g., *bufio.Writer vs *bytes.Buffer) will never compare equal.

func (*ByteVectorInputPort) IsClosed 

func (p *ByteVectorInputPort) IsClosed() bool

IsClosed returns true if the port has been closed.

func (*ByteVectorInputPort) IsVoid 

func (p *ByteVectorInputPort) IsVoid() bool

IsVoid returns true if the port is nil.

func (*ByteVectorInputPort) Read 

func (p *ByteVectorInputPort) Read(bs []byte) (int, error)

func (*ByteVectorInputPort) ReadByte 

func (p *ByteVectorInputPort) ReadByte() (byte, error)

ReadByte reads and returns the next byte from the port.

func (*ByteVectorInputPort) SchemeString 

func (p *ByteVectorInputPort) SchemeString() string

SchemeString returns the Scheme external representation of the port.

func (*ByteVectorInputPort) UnreadByte 

func (p *ByteVectorInputPort) UnreadByte() error

UnreadByte unreads the last byte read, allowing it to be read again.

type ByteVectorOutputPort 

type ByteVectorOutputPort struct {
	// contains filtered or unexported fields
}

ByteVectorOutputPort represents a Scheme output port writing to memory.

func NewByteVectorOutputPortFromWriter 

func NewByteVectorOutputPortFromWriter(wrt io.Writer) *ByteVectorOutputPort

NewByteVectorOutputPortFromWriter creates a new in-memory bytevector output port.

func (*ByteVectorOutputPort) Close 

func (p *ByteVectorOutputPort) Close() error

Close flushes buffered data and closes the underlying stream.

func (*ByteVectorOutputPort) Datum 

func (p *ByteVectorOutputPort) Datum() *bufio.Writer

Datum returns the underlying bytes.Buffer.

func (*ByteVectorOutputPort) EqualTo 

func (p *ByteVectorOutputPort) EqualTo(v Value) bool

EqualTo returns true if v is a port with the same kind and datum identity. This works because Go's any equality checks both dynamic type and value, so two ports sharing a kind but using different backing types (e.g., *bufio.Writer vs *bytes.Buffer) will never compare equal.

func (*ByteVectorOutputPort) Flush 

func (p *ByteVectorOutputPort) Flush() error

func (*ByteVectorOutputPort) IsClosed 

func (p *ByteVectorOutputPort) IsClosed() bool

IsClosed returns true if the port has been closed.

func (*ByteVectorOutputPort) IsVoid 

func (p *ByteVectorOutputPort) IsVoid() bool

IsVoid returns true if the port is nil.

func (*ByteVectorOutputPort) SchemeString 

func (p *ByteVectorOutputPort) SchemeString() string

SchemeString returns the Scheme external representation of the port.

func (*ByteVectorOutputPort) Write 

func (p *ByteVectorOutputPort) Write(bs []byte) (int, error)

func (*ByteVectorOutputPort) WriteByte 

func (p *ByteVectorOutputPort) WriteByte(b byte) error

type Callable added in v1.5.0 

type Callable interface {
	Value
	AcceptsArity(n int) bool
}

Callable represents a Scheme procedure — any value that can be applied to arguments.

R7RS §6.1: The procedure? predicate returns #t for all callable types. This includes lambdas, case-lambdas, parameter objects (R7RS §4.2.6), and composable continuations.

AcceptsArity reports whether the procedure can be called with exactly n arguments. This captures arity constraints that are otherwise scattered across per-type checks in the VM apply path.

Implemented by: MachineClosure, CaseLambdaClosure, Parameter, ComposableContinuation.

type Channel 

type Channel struct {
	// contains filtered or unexported fields
}

Channel represents a Go channel exposed to Scheme

func NewChannel 

func NewChannel(bufferSize int) *Channel

NewChannel creates a new channel with the given buffer size bufferSize of 0 creates an unbuffered channel

func (*Channel) BufferSize 

func (p *Channel) BufferSize() int

BufferSize returns the channel's buffer size

func (*Channel) Cap 

func (p *Channel) Cap() int

Cap returns the channel's capacity

func (*Channel) Chan 

func (p *Channel) Chan() chan Value

Chan returns the underlying Go channel for use in select statements

func (*Channel) Close 

func (p *Channel) Close() error

Close closes the channel

func (*Channel) EqualTo 

func (p *Channel) EqualTo(v Value) bool

EqualTo returns true if both channels are the same object.

func (*Channel) ID 

func (p *Channel) ID() uint64

ID returns the channel's unique identifier

func (*Channel) IsClosed 

func (p *Channel) IsClosed() bool

IsClosed returns true if the channel is closed

func (*Channel) IsVoid 

func (p *Channel) IsVoid() bool

IsVoid returns true if this channel is nil.

func (*Channel) Len 

func (p *Channel) Len() int

Len returns the number of elements queued in the channel

func (*Channel) Receive 

func (p *Channel) Receive() (Value, bool)

Receive receives a value from the channel (blocking) Returns the value and true, or nil and false if channel is closed

func (*Channel) SchemeString 

func (p *Channel) SchemeString() string

SchemeString returns the Scheme representation of this channel.

func (*Channel) Send 

func (p *Channel) Send(v Value) error

Send sends a value on the channel (blocking)

func (*Channel) TryReceive 

func (p *Channel) TryReceive() (Value, bool, bool)

TryReceive attempts to receive a value without blocking Returns (value, true, true) if received Returns (nil, false, true) if would block Returns (nil, false, false) if channel is closed

func (*Channel) TrySend 

func (p *Channel) TrySend(v Value) (bool, error)

TrySend attempts to send a value without blocking Returns true if sent, false if would block

type Character 

type Character struct {
	Value rune
}

Character represents a Scheme character value.

func NewCharacter 

func NewCharacter(v rune) *Character

NewCharacter creates a new character from a rune.

func (*Character) Datum 

func (p *Character) Datum() rune

Datum returns the underlying rune value.

func (*Character) EqualTo 

func (p *Character) EqualTo(v Value) bool

EqualTo returns true if both characters have the same rune value.

func (*Character) HashCode 

func (p *Character) HashCode() uint64

HashCode returns a hash of the character value.

func (*Character) IsVoid 

func (p *Character) IsVoid() bool

IsVoid returns true if the character is nil.

func (*Character) SchemeString 

func (p *Character) SchemeString() string

SchemeString returns the Scheme representation of the character. Named characters use the R7RS mnemonic form (#\newline). Graphic characters use #\<char>. Non-graphic non-named characters use #\xHEX for round-trip safety.

func (*Character) String 

func (p *Character) String() string

type CharacterInputPort 

type CharacterInputPort struct {
	// contains filtered or unexported fields
}

CharacterInputPort represents a Scheme textual input port.

func NewCharacterInputPort 

func NewCharacterInputPort(rdr *bufio.Reader) *CharacterInputPort

NewCharacterInputPort creates a new character input port from an io.RuneReader.

func NewCharacterInputPortFromReader 

func NewCharacterInputPortFromReader(rdr io.Reader) *CharacterInputPort

NewCharacterInputPortFromReader creates a new character input port from an io.Reader.

func (*CharacterInputPort) Close 

func (p *CharacterInputPort) Close() error

Close marks the port as closed and, if a closer was provided, closes the underlying stream. Close is idempotent.

func (*CharacterInputPort) Datum 

func (p *CharacterInputPort) Datum() io.RuneReader

Datum returns the underlying io.RuneReader.

func (*CharacterInputPort) EqualTo 

func (p *CharacterInputPort) EqualTo(v Value) bool

EqualTo returns true if v is a port with the same kind and datum identity. This works because Go's any equality checks both dynamic type and value, so two ports sharing a kind but using different backing types (e.g., *bufio.Writer vs *bytes.Buffer) will never compare equal.

func (*CharacterInputPort) IsClosed 

func (p *CharacterInputPort) IsClosed() bool

IsClosed returns true if the port has been closed.

func (*CharacterInputPort) IsVoid 

func (p *CharacterInputPort) IsVoid() bool

IsVoid returns true if the port is nil.

func (*CharacterInputPort) Read 

func (p *CharacterInputPort) Read(bs []byte) (int, error)

func (*CharacterInputPort) ReadRune 

func (p *CharacterInputPort) ReadRune() (rune, int, error)

func (*CharacterInputPort) SchemeString 

func (p *CharacterInputPort) SchemeString() string

SchemeString returns the Scheme external representation of the port.

func (*CharacterInputPort) UnreadRune 

func (p *CharacterInputPort) UnreadRune() error

type CharacterOutputPort 

type CharacterOutputPort struct {
	// contains filtered or unexported fields
}

CharacterOutputPort represents a Scheme textual output port.

func NewCharacterOutputPortFromWriter 

func NewCharacterOutputPortFromWriter(wrt io.Writer) *CharacterOutputPort

NewCharacterOutputPortFromWriter creates a new character output port wrapping the given buf.

func (*CharacterOutputPort) Close 

func (p *CharacterOutputPort) Close() error

Close flushes buffered data and closes the underlying stream.

func (*CharacterOutputPort) Datum 

func (p *CharacterOutputPort) Datum() io.Writer

Datum returns the underlying data of the CharacterOutputPort as an io.Writer. there is no RunWriter interface in the standard library, so we just use io.Writer here.

func (*CharacterOutputPort) EqualTo 

func (p *CharacterOutputPort) EqualTo(v Value) bool

EqualTo returns true if v is a port with the same kind and datum identity. This works because Go's any equality checks both dynamic type and value, so two ports sharing a kind but using different backing types (e.g., *bufio.Writer vs *bytes.Buffer) will never compare equal.

func (*CharacterOutputPort) Flush 

func (p *CharacterOutputPort) Flush() error

func (*CharacterOutputPort) IsClosed 

func (p *CharacterOutputPort) IsClosed() bool

IsClosed returns true if the port has been closed.

func (*CharacterOutputPort) IsVoid 

func (p *CharacterOutputPort) IsVoid() bool

IsVoid returns true if the port is nil.

func (*CharacterOutputPort) SchemeString 

func (p *CharacterOutputPort) SchemeString() string

SchemeString returns the Scheme external representation of the port.

func (*CharacterOutputPort) Write 

func (p *CharacterOutputPort) Write(bs []byte) (int, error)

func (*CharacterOutputPort) WriteRune 

func (p *CharacterOutputPort) WriteRune(rn rune) (int, error)

WriteRune writes a single rune to the port's buf.

func (*CharacterOutputPort) WriteString 

func (p *CharacterOutputPort) WriteString(s string) (int, error)

type CompileTimeValue 

type CompileTimeValue struct {
	Value Value
}

CompileTimeValue wraps a value that is stored in the expand phase but accessible during macro expansion. This enables compile-time computation via define-for-syntax and begin-for-syntax.

func NewCompileTimeValue 

func NewCompileTimeValue(v Value) *CompileTimeValue

NewCompileTimeValue creates a new compile-time value.

func (*CompileTimeValue) EqualTo 

func (p *CompileTimeValue) EqualTo(v Value) bool

EqualTo returns true if the compile-time values are equal.

func (*CompileTimeValue) IsVoid 

func (p *CompileTimeValue) IsVoid() bool

IsVoid returns true if the compile-time value is nil.

func (*CompileTimeValue) SchemeString 

func (p *CompileTimeValue) SchemeString() string

SchemeString returns the Scheme representation of the compile-time value.

func (*CompileTimeValue) Unwrap 

func (p *CompileTimeValue) Unwrap() Value

Unwrap returns the underlying value.

type Complex 

type Complex struct {
	Value complex128
}

Complex represents a Scheme complex number.

func NewComplex 

func NewComplex(v complex128) *Complex

NewComplex creates a new complex number from a complex128 value.

func NewComplexFromParts 

func NewComplexFromParts(realPart, imagPart float64) *Complex

NewComplexFromParts creates a new complex number from real and imaginary parts.

func (*Complex) Abs added in v1.1.0 

func (p *Complex) Abs() Number

Abs returns the magnitude of this complex number.

R7RS §6.2.6: For complex numbers, abs returns the magnitude.

func (*Complex) Add 

func (p *Complex) Add(o Number) Number

Add returns the sum of this complex number and another number. Zero short-circuit: 0+x=x preserves exactness per R7RS §6.2.2.

func (*Complex) Compare 

func (p *Complex) Compare(o Number) int

Compare compares this complex number with another number by real parts.

R7RS §6.2.6: Complex comparison compares real parts only. Returns -1 if p < o, 0 if p == o, 1 if p > o.

func (*Complex) Datum 

func (p *Complex) Datum() complex128

Datum returns the underlying complex128 value.

func (*Complex) Divide 

func (p *Complex) Divide(o Number) (Number, error)

Divide returns the quotient of this complex number and another number.

func (*Complex) EqualTo 

func (p *Complex) EqualTo(v Value) bool

EqualTo returns true if both complex numbers have the same value.

func (*Complex) HashCode added in v1.5.0 

func (p *Complex) HashCode() uint64

HashCode returns a hash of the complex value. Hashes real and imaginary parts independently via hashComplexComponent and combines them with a multiplicative mixing constant. NaN and ±Inf components use bitwise hashing to avoid big.Float panics.

func (*Complex) Imag 

func (p *Complex) Imag() float64

Imag returns the imaginary part of the complex number.

func (*Complex) ImagPart added in v1.1.0 

func (p *Complex) ImagPart() Number

ImagPart returns the imaginary part of this complex number as a Number.

R7RS §6.2.6: imag-part returns the imaginary part of a complex number.

func (*Complex) IsExact 

func (p *Complex) IsExact() bool

IsExact returns false since Complex is always inexact.

R7RS §6.2.2: Complex numbers with floating-point components are inexact.

func (*Complex) IsFinite added in v1.1.0 

func (p *Complex) IsFinite() bool

IsFinite returns true if both real and imaginary parts are finite.

R7RS §6.2.6: finite? returns #t if neither part is Inf or NaN.

func (*Complex) IsInteger added in v1.1.0 

func (p *Complex) IsInteger() bool

IsInteger returns true if this complex has zero imaginary part and an integer real part.

R7RS §6.2.6: integer? returns #t for complex numbers with zero imaginary part whose real part is an integer.

func (*Complex) IsNaN added in v1.1.0 

func (p *Complex) IsNaN() bool

IsNaN returns true if either the real or imaginary part is NaN.

R7RS §6.2.6: nan? returns #t if any component is NaN.

func (*Complex) IsRational added in v1.1.0 

func (p *Complex) IsRational() bool

IsRational returns true if the imaginary part is zero and the real part is finite.

R7RS §6.2.6: A complex number with zero imaginary part is rational if its real part is a finite real number.

func (*Complex) IsReal 

func (p *Complex) IsReal() bool

IsReal returns true if the imaginary part is zero.

func (*Complex) IsVoid 

func (p *Complex) IsVoid() bool

IsVoid returns true if this complex number is nil.

func (*Complex) IsZero 

func (p *Complex) IsZero() bool

IsZero returns true if this complex number is zero.

func (*Complex) Kind added in v1.5.0 

func (p *Complex) Kind() NumericKind

Kind returns the numeric kind for dispatch table indexing.

func (*Complex) LessThan 

func (p *Complex) LessThan(o Number) bool

LessThan compares the real parts of the complex numbers.

func (*Complex) Magnitude 

func (p *Complex) Magnitude() float64

Magnitude returns the absolute value (modulus) of the complex number.

func (*Complex) Multiply 

func (p *Complex) Multiply(o Number) Number

Multiply returns the product of this complex number and another number.

func (*Complex) Negate 

func (p *Complex) Negate() Number

Negate returns the negation of this complex number.

R7RS §6.2.6: The - procedure with one argument returns the additive inverse.

func (*Complex) Phase 

func (p *Complex) Phase() float64

Phase returns the phase (argument) of the complex number in radians.

func (*Complex) Real 

func (p *Complex) Real() float64

Real returns the real part of the complex number.

func (*Complex) RealPart added in v1.1.0 

func (p *Complex) RealPart() Number

RealPart returns the real part of this complex number as a Number.

R7RS §6.2.6: real-part returns the real part of a complex number.

func (*Complex) SchemeString 

func (p *Complex) SchemeString() string

SchemeString returns the Scheme representation of this complex number. R7RS §6.2.6: Ensures decimal point for inexact values, lowercase inf/nan.

func (*Complex) Subtract 

func (p *Complex) Subtract(o Number) Number

Subtract returns the difference of this complex number and another number.

func (*Complex) ToExact added in v1.1.0 

func (p *Complex) ToExact() (Number, error)

ToExact converts this Complex to an exact representation.

R7RS §6.2.6: exact returns an exact representation of its argument. Both real and imaginary parts are converted to exact numbers.

func (*Complex) ToInexact added in v1.1.0 

func (p *Complex) ToInexact() Number

ToInexact returns this Complex unchanged since it is already inexact.

R7RS §6.2.6: inexact returns an inexact representation of its argument.

type ComplexNumber added in v1.1.0 

type ComplexNumber interface {
	Number
	RealPart() Number
	ImagPart() Number
	IsReal() bool
}

ComplexNumber represents a complex-valued number with accessible parts.

R7RS §6.2.6: Complex numbers have real and imaginary parts accessible via real-part and imag-part.

type ConditionVariable 

type ConditionVariable struct {
	// contains filtered or unexported fields
}

ConditionVariable represents a Scheme condition variable (SRFI-18)

func NewConditionVariable 

func NewConditionVariable(name string) *ConditionVariable

NewConditionVariable creates a new condition variable

func (*ConditionVariable) Broadcast 

func (p *ConditionVariable) Broadcast()

Broadcast wakes all waiting threads.

func (*ConditionVariable) EqualTo 

func (p *ConditionVariable) EqualTo(v Value) bool

EqualTo returns true if the condition variables are the same object.

func (*ConditionVariable) ID 

func (p *ConditionVariable) ID() uint64

ID returns the condition variable's unique identifier

func (*ConditionVariable) IsVoid 

func (p *ConditionVariable) IsVoid() bool

IsVoid returns true if the condition variable is nil.

func (*ConditionVariable) Name 

func (p *ConditionVariable) Name() string

Name returns the condition variable's name

func (*ConditionVariable) SchemeString 

func (p *ConditionVariable) SchemeString() string

SchemeString returns the Scheme representation of this condition variable.

func (*ConditionVariable) SetSpecific 

func (p *ConditionVariable) SetSpecific(v Value)

SetSpecific sets the condition variable's specific field

func (*ConditionVariable) Signal 

func (p *ConditionVariable) Signal()

Signal wakes one waiting thread (FIFO order).

func (*ConditionVariable) Specific 

func (p *ConditionVariable) Specific() Value

Specific returns the condition variable's specific field

func (*ConditionVariable) Wait 

func (p *ConditionVariable) Wait(_ *Mutex, timeout *time.Duration) bool

Wait waits on the condition variable. Returns true if signaled, false if timeout.

Each waiter registers a per-waiter channel. Signal/Broadcast close the channel to wake the waiter. Timeouts remove the channel from the queue without disturbing other waiters.

func (*ConditionVariable) WaiterCount 

func (p *ConditionVariable) WaiterCount() int

WaiterCount returns the number of threads waiting on this condition variable.

type DebugLocation added in v1.13.14 

type DebugLocation struct {
	File   string
	Line   int
	Column int
}

DebugLocation holds file/line/column for debug and error display. This is a simple struct for presentation layers (REPL, debugger UI), distinct from the SourceLocation interface which is a full Value type used by procedure-source-location.

type DebugState added in v1.13.14 

type DebugState interface {
	// CurrentLocation returns the source location at the current
	// execution point, or nil if no source info is available.
	CurrentLocation() *DebugLocation

	// FormatStackTrace returns a human-readable stack trace string,
	// walking at most maxDepth frames.
	FormatStackTrace(maxDepth int) string
}

DebugState provides read-only access to VM execution state. Implemented by the VM's MachineContext; consumed by presentation layers (REPL, debugger UI) without importing machine/.

type Exactness 

type Exactness int

Exactness represents whether a number is exact or inexact.

R7RS §6.2.2: Numbers are either exact or inexact. A number is exact if it was written as an exact constant or derived from exact numbers using only exact operations. Otherwise, it is inexact. 

const (
	Exact Exactness = iota
	Inexact
)

Exactness constants for R7RS exact/inexact classification.

func ExactnessOf 

func ExactnessOf(n Number) Exactness

ExactnessOf returns the exactness of a number.

R7RS §6.2.2: - Integer, BigInteger, Rational are exact - Float, BigFloat, Complex are inexact - BigComplex depends on its components

type Float 

type Float struct {
	Value float64
}

Float represents a Scheme floating-point number.

func NewFloat 

func NewFloat(v float64) *Float

NewFloat creates a new float value.

func (*Float) Abs 

func (p *Float) Abs() Number

Abs returns the absolute value of this float.

func (*Float) Add 

func (p *Float) Add(o Number) Number

R7RS §6.2.6: The + procedure returns the sum of its arguments. R7RS §6.2.2 Exactness: inexact + inexact = inexact, exact + inexact = inexact.

func (*Float) Compare 

func (p *Float) Compare(o Number) int

Compare compares this float with another number.

R7RS §6.2.6: Numeric comparisons use mathematical value regardless of exactness. Returns -1 if p < o, 0 if p == o, 1 if p > o.

func (*Float) Datum 

func (p *Float) Datum() float64

Datum returns the underlying float64 value.

func (*Float) Divide 

func (p *Float) Divide(o Number) (Number, error)

Divide returns the quotient of this float and another number.

func (*Float) EqualTo 

func (p *Float) EqualTo(v Value) bool

EqualTo returns true if both floats have the same value. Handles comparison with both Float and BigFloat types for symmetry.

func (*Float) HashCode 

func (p *Float) HashCode() uint64

HashCode returns a hash of the float value. Uses the canonical inexact-family hash so that Float and BigFloat produce identical hashes for equal values. NaN and Inf use bitwise hashing as a fallback since BigFloat has no Inf/NaN, making cross-type equality impossible for those values.

func (*Float) IsExact 

func (p *Float) IsExact() bool

IsExact returns false since Float is always inexact.

R7RS §6.2.2: Floating-point numbers are inexact.

func (*Float) IsFinite added in v1.1.0 

func (p *Float) IsFinite() bool

IsFinite returns true if this float is finite (not Inf or NaN).

R7RS §6.2.6: finite? returns #t for finite numbers.

func (*Float) IsInteger added in v1.1.0 

func (p *Float) IsInteger() bool

IsInteger returns true if this float represents an integer value.

R7RS §6.2.6: integer? returns #t for inexact integers (e.g., 3.0). Uses math.Trunc to correctly handle large floats outside int64 range.

func (*Float) IsNaN added in v1.1.0 

func (p *Float) IsNaN() bool

IsNaN returns true if this float is NaN.

R7RS §6.2.6: nan? returns #t for NaN values.

func (*Float) IsNegative added in v1.1.0 

func (p *Float) IsNegative() bool

IsNegative returns true if this float is negative.

func (*Float) IsPositive added in v1.1.0 

func (p *Float) IsPositive() bool

IsPositive returns true if this float is positive.

func (*Float) IsRational added in v1.1.0 

func (p *Float) IsRational() bool

IsRational returns true if this float is finite (not NaN or Inf).

R7RS §6.2.6: rational? returns #t for finite inexact reals.

func (*Float) IsVoid 

func (p *Float) IsVoid() bool

IsVoid returns true if the float is nil.

func (*Float) IsZero 

func (p *Float) IsZero() bool

IsZero returns true if this float is zero.

func (*Float) Kind added in v1.5.0 

func (p *Float) Kind() NumericKind

Add returns the sum of two numbers.

Kind returns the numeric kind for dispatch table indexing.

func (*Float) LessThan 

func (p *Float) LessThan(o Number) bool

LessThan returns true if this float is less than another number.

func (*Float) Multiply 

func (p *Float) Multiply(o Number) Number

Multiply returns the product of two numbers.

R7RS §6.2.6: The * procedure returns the product of its arguments. R7RS §6.2.2: Exact zero dominates—(* 0 x) may return exact 0 even when x is inexact. Zero is an exact value when the result is mathematically unambiguous. This implementation follows Chez Scheme's behavior.

func (*Float) Negate 

func (p *Float) Negate() Number

Negate returns the negation of this float.

R7RS §6.2.6: The - procedure with one argument returns the additive inverse.

func (*Float) SchemeString 

func (p *Float) SchemeString() string

SchemeString returns the Scheme representation of the float.

R7RS §6.2.5: +inf.0, -inf.0, and +nan.0 are the written representations for positive infinity, negative infinity, and NaN. R7RS §7.1.1: Inexact real numbers must contain a decimal point to distinguish them from exact integers.

func (*Float) Sign added in v1.1.0 

func (p *Float) Sign() int

Sign returns -1 if negative, 0 if zero, or 1 if positive. NaN returns 0.

func (*Float) String 

func (p *Float) String() string

func (*Float) Subtract 

func (p *Float) Subtract(o Number) Number

Subtract returns the difference of two numbers.

R7RS §6.2.6: The - procedure returns the difference of its arguments. R7RS §6.2.2 Exactness: inexact - inexact = inexact, exact - inexact = inexact.

func (*Float) ToExact added in v1.1.0 

func (p *Float) ToExact() (Number, error)

ToExact converts this Float to an exact Number.

R7RS §6.2.6: exact returns an exact representation of its argument. Returns Integer if the float is integral, Rational otherwise.

func (*Float) ToInexact added in v1.1.0 

func (p *Float) ToInexact() Number

ToInexact returns this Float unchanged since it is already inexact.

R7RS §6.2.6: inexact returns an inexact representation of its argument.

type ForEachFunc 

type ForEachFunc func(ctx context.Context, i int, hasNext bool, v Value) error

ForEachFunc is the callback signature for iterating over a Tuple.

Parameters:

  • ctx: context for cancellation
  • i: zero-based element index
  • hasNext: true if more elements follow
  • v: the current element value

Return a non-nil error to stop iteration early.

type Hashable 

type Hashable interface {
	Value
	HashCode() uint64
}

Hashable represents a Value that can be used as a hashtable key.

R7RS §6.10: Hashtables map keys to values. Keys are compared using equal?, and the hash function must be consistent with the equality predicate: if a.EqualTo(b) then a.HashCode() == b.HashCode().

Implemented by: Integer, BigInteger, Float, BigFloat, Rational, Boolean, Character, Symbol, Byte, String.

type Hashtable 

type Hashtable struct {
	// contains filtered or unexported fields
}

Hashtable represents a Scheme hash table mapping hashable values to values.

Separate chaining (Cormen et al., CLRS Ch. 11): collisions are resolved by storing all entries with the same hash in a linked list (here, a Go slice). O(1) amortized with a good hash function. See BIBLIOGRAPHY.md "Separate Chaining Hash Table".

Keys must implement the Hashable interface (Value + HashCode()). Uses bucket chaining with FNV-1a hashing for O(1) amortized operations and EqualTo() for key comparison within buckets.

func NewEmptyHashtable 

func NewEmptyHashtable() *Hashtable

NewEmptyHashtable creates a new empty hash table.

func (*Hashtable) Clear 

func (p *Hashtable) Clear()

Clear removes all entries from the hash table.

func (*Hashtable) Copy 

func (p *Hashtable) Copy() *Hashtable

Copy returns a shallow copy of the hash table.

func (*Hashtable) Delete 

func (p *Hashtable) Delete(key Value) error

Delete removes the entry for key from the hash table. Returns werr.ErrInvalidArgument if the key does not implement Hashable.

func (*Hashtable) Entries added in v1.1.0 

func (p *Hashtable) Entries(fn func(key Hashable, value Value) error) error

Entries iterates over all entries in the hash table, calling fn for each key-value pair. Iteration stops early if fn returns a non-nil error. This is more efficient than Keys()+Get() as it avoids intermediate allocations.

func (*Hashtable) EqualTo 

func (p *Hashtable) EqualTo(o Value) bool

EqualTo returns true if both hash tables have equal contents. Uses structural equality (EqualTo) for both keys and values.

func (*Hashtable) Get 

func (p *Hashtable) Get(key Value) (Value, bool, error)

Get retrieves the value associated with key. Returns the value and whether the key was found. Returns werr.ErrInvalidArgument if the key does not implement Hashable.

func (*Hashtable) HasKey 

func (p *Hashtable) HasKey(key Value) (bool, error)

HasKey returns whether the key exists in the hash table. Returns werr.ErrInvalidArgument if the key does not implement Hashable.

func (*Hashtable) IsVoid 

func (p *Hashtable) IsVoid() bool

IsVoid returns true if this hash table is nil.

func (*Hashtable) Keys 

func (p *Hashtable) Keys() Tuple

Keys returns a list of all keys in the hash table.

func (*Hashtable) SchemeString 

func (p *Hashtable) SchemeString() string

SchemeString returns the Scheme representation of this hash table.

func (*Hashtable) Set 

func (p *Hashtable) Set(key Value, val Value) error

Set associates key with val in the hash table. Returns werr.ErrInvalidArgument if the key does not implement Hashable.

func (*Hashtable) Size 

func (p *Hashtable) Size() int

Size returns the number of entries in the hash table.

func (*Hashtable) Values 

func (p *Hashtable) Values() Tuple

Values returns a list of all values in the hash table.

type InputOutputPort 

type InputOutputPort interface {
	InputPort
	OutputPort
}

InputOutputPort represents a bidirectional Scheme port.

type InputPort 

type InputPort interface {
	Port
	Read([]byte) (int, error)
}

InputPort represents a Scheme input port.

type Integer 

type Integer struct {
	Value int64
}

Integer represents a Scheme integer value.

R7RS §6.2.1: Integers are exact numbers in the numeric tower hierarchy: 

number ⊃ complex ⊃ real ⊃ rational ⊃ integer

R7RS §6.2.2: Integer is always exact. Operations on exact numbers produce exact results when mathematically well-defined.

func NewInteger 

func NewInteger(v int64) *Integer

NewInteger returns an Integer value. Small integers in the range -32768 to 32767 are cached and return the same pointer for the same value.

func (*Integer) Abs 

func (p *Integer) Abs() Number

func (*Integer) Add 

func (p *Integer) Add(o Number) Number

R7RS §6.2.2 Exactness: exact + exact = exact, exact + inexact = inexact. When adding Integer + BigInteger, result is BigInteger (exact). When adding Integer + Float/Complex, result is Float/Complex (inexact).

func (*Integer) Compare 

func (p *Integer) Compare(o Number) int

Compare compares this integer with another number.

R7RS §6.2.6: Numeric comparisons use mathematical value regardless of exactness. Returns -1 if p < o, 0 if p == o, 1 if p > o.

func (*Integer) Datum 

func (p *Integer) Datum() int64

Datum returns the underlying int64 value.

func (*Integer) Divide 

func (p *Integer) Divide(o Number) (Number, error)

Divide returns the quotient of this integer and another number.

R7RS §6.2.6: The / procedure returns the quotient of its arguments. For exact arguments, / may return a non-integer (Rational) when the mathematical result is not an integer. Returns Integer only when the division is exact.

R7RS §6.2.2 Exactness: exact / exact = exact (Integer or Rational), exact / inexact = inexact (Float or Complex).

func (*Integer) EqualTo 

func (p *Integer) EqualTo(v Value) bool

EqualTo returns true if both integers have the same value.

R7RS §6.2.6: The = procedure compares numerical values for equality. This implements structural equality for the Integer type specifically. Handles comparison with Integer, BigInteger, and Rational types for symmetry.

func (*Integer) HashCode 

func (p *Integer) HashCode() uint64

HashCode returns a hash of the integer value. Uses the canonical exact-family hash so that Integer, BigInteger, and Rational produce identical hashes for equal values.

func (*Integer) IsExact 

func (p *Integer) IsExact() bool

IsExact returns true since Integer is always exact.

R7RS §6.2.2: Integers are always exact numbers.

func (*Integer) IsFinite added in v1.1.0 

func (p *Integer) IsFinite() bool

IsFinite returns true since integers are always finite.

R7RS §6.2.6: finite? returns #t for all exact numbers.

func (*Integer) IsInteger added in v1.1.0 

func (p *Integer) IsInteger() bool

IsInteger returns true since Integer is always an integer.

R7RS §6.2.6: integer? returns #t for exact integers.

func (*Integer) IsNaN added in v1.1.0 

func (p *Integer) IsNaN() bool

IsNaN returns false since integers are never NaN.

R7RS §6.2.6: nan? returns #f for exact numbers.

func (*Integer) IsNegative added in v1.1.0 

func (p *Integer) IsNegative() bool

IsNegative returns true if this integer is negative.

R7RS §6.2.6: negative? returns #t if the real number is negative.

func (*Integer) IsPositive added in v1.1.0 

func (p *Integer) IsPositive() bool

IsPositive returns true if this integer is positive.

R7RS §6.2.6: positive? returns #t if the real number is positive.

func (*Integer) IsRational added in v1.1.0 

func (p *Integer) IsRational() bool

IsRational returns true since integers are a subset of rationals.

R7RS §6.2.6: rational? returns #t for all real finite numbers.

func (*Integer) IsVoid 

func (p *Integer) IsVoid() bool

IsVoid returns true if this integer is nil.

func (*Integer) IsZero 

func (p *Integer) IsZero() bool

IsZero returns true if this integer is zero.

func (*Integer) Kind added in v1.5.0 

func (p *Integer) Kind() NumericKind

Add returns the sum of this integer and another number.

R7RS §6.2.6: The + procedure returns the sum of its arguments. Kind returns the numeric kind for dispatch table indexing.

func (*Integer) LessThan 

func (p *Integer) LessThan(o Number) bool

LessThan returns true if this integer is less than another number.

R7RS §6.2.6: The < procedure returns #t if its arguments are monotonically increasing. Comparison across numeric types uses mathematical value.

func (*Integer) Multiply 

func (p *Integer) Multiply(o Number) Number

Multiply returns the product of this integer and another number.

R7RS §6.2.6: The * procedure returns the product of its arguments. R7RS §6.2.2 Exactness: exact * exact = exact, exact * inexact = inexact. Exception: Exact zero dominates—(* 0 x) may return exact 0 even when x is inexact. Zero is an exact value when the result is mathematically unambiguous. This implementation follows Chez Scheme's behavior.

func (*Integer) Negate 

func (p *Integer) Negate() Number

Negate returns the negation of this integer.

R7RS §6.2.6: The - procedure with one argument returns the additive inverse.

func (*Integer) SchemeString 

func (p *Integer) SchemeString() string

SchemeString returns the Scheme representation of this integer.

func (*Integer) Sign added in v1.1.0 

func (p *Integer) Sign() int

Sign returns -1 if negative, 0 if zero, or 1 if positive.

func (*Integer) Subtract 

func (p *Integer) Subtract(o Number) Number

Subtract returns the difference of this integer and another number.

R7RS §6.2.6: The - procedure returns the difference of its arguments. R7RS §6.2.2 Exactness: exact - exact = exact, exact - inexact = inexact.

func (*Integer) ToExact added in v1.1.0 

func (p *Integer) ToExact() (Number, error)

ToExact returns this Integer unchanged since it is already exact.

R7RS §6.2.6: exact returns an exact representation of its argument.

func (*Integer) ToInexact added in v1.1.0 

func (p *Integer) ToInexact() Number

ToInexact converts this Integer to an inexact Float.

R7RS §6.2.6: inexact returns an inexact representation of its argument.

type JoinTimeoutException 

type JoinTimeoutException struct{}

JoinTimeoutException is raised when thread-join! times out

func (*JoinTimeoutException) Error 

func (p *JoinTimeoutException) Error() string

type Mutex 

type Mutex struct {
	// contains filtered or unexported fields
}

Mutex represents a Scheme mutex (SRFI-18)

func NewMutex 

func NewMutex(name string) *Mutex

NewMutex creates a new unlocked mutex

func (*Mutex) EqualTo 

func (p *Mutex) EqualTo(v Value) bool

EqualTo returns true if the mutexes are the same object.

func (*Mutex) ID 

func (p *Mutex) ID() uint64

ID returns the mutex's unique identifier

func (*Mutex) IsVoid 

func (p *Mutex) IsVoid() bool

IsVoid returns true if the mutex is nil.

func (*Mutex) Lock 

func (p *Mutex) Lock(timeout *time.Duration, owner *Thread) (bool, error)

Lock acquires the mutex with optional timeout and owner Returns true if acquired, false if timeout

func (*Mutex) MarkAbandoned 

func (p *Mutex) MarkAbandoned()

MarkAbandoned marks the mutex as abandoned (called when owner thread terminates)

func (*Mutex) Name 

func (p *Mutex) Name() string

Name returns the mutex's name

func (*Mutex) Owner 

func (p *Mutex) Owner() *Thread

Owner returns the current owner thread, or nil if not owned

func (*Mutex) SchemeString 

func (p *Mutex) SchemeString() string

SchemeString returns the Scheme representation of the mutex.

func (*Mutex) SetSpecific 

func (p *Mutex) SetSpecific(v Value)

SetSpecific sets the mutex's specific field

func (*Mutex) Specific 

func (p *Mutex) Specific() Value

Specific returns the mutex's specific field

func (*Mutex) State 

func (p *Mutex) State() MutexState

State returns the current state of the mutex

func (*Mutex) StateValue 

func (p *Mutex) StateValue() Value

StateValue returns the state as a Scheme value. Returns package-level singletons for symbol states so that repeated calls return the same pointer: (eq? (mutex-state m) (mutex-state m)) → #t. See the doc comment on SymbolThreadNew in thread.go for eq? vs equal? caveats. Returns: 'not-owned, 'abandoned, or the owner thread.

func (*Mutex) Unlock 

func (p *Mutex) Unlock(cv *ConditionVariable, timeout *time.Duration) bool

Unlock releases the mutex If cv is provided, atomically unlock and wait on condition variable

type MutexState 

type MutexState int

MutexState represents the state of a mutex 

const (
	MutexUnlocked       MutexState = iota // Not locked
	MutexLockedOwned                      // Locked with owner
	MutexLockedNotOwned                   // Locked without owner
	MutexAbandoned                        // Owner terminated while holding lock
)

MutexState constants.

func (MutexState) String 

func (p MutexState) String() string

type NamedTypeConstraint added in v1.12.0 

type NamedTypeConstraint struct {
	// contains filtered or unexported fields
}

NamedTypeConstraint represents an unresolved type name from a docstring (e.g., "point"). It is documentation-only — Check always fails because the constraint has not been resolved to a concrete type.

func NewNamedTypeConstraint added in v1.12.0 

func NewNamedTypeConstraint(name string) *NamedTypeConstraint

NewNamedTypeConstraint creates a NamedTypeConstraint with the given name.

func (*NamedTypeConstraint) Check added in v1.12.0 

func (p *NamedTypeConstraint) Check(v Value) (any, bool, error)

Check always fails — the constraint is unresolved and cannot validate values.

func (*NamedTypeConstraint) Description added in v1.12.0 

func (p *NamedTypeConstraint) Description() string

Description returns the unresolved type name as its description.

func (*NamedTypeConstraint) Name added in v1.12.0 

func (p *NamedTypeConstraint) Name() string

Name returns the unresolved type name.

type NativeError 

type NativeError struct {
	// contains filtered or unexported fields
}

NativeError represents an R7RS error object created by (error ...). It contains a message string and a list of irritant objects that provide additional context about the error. It can also wrap a Go error.

func NewErrorObject 

func NewErrorObject(message string, irritants ...Value) *NativeError

NewErrorObject creates a new error object with the given message and irritants.

func NewErrorObjectWithCause 

func NewErrorObjectWithCause(message string, cause error, irritants ...Value) *NativeError

NewErrorObjectWithCause creates a new error object that wraps a Go error. This preserves the original error for debugging while providing R7RS-compliant exception handling. The wrapped error can be retrieved with Datum() or Unwrap().

func NewErrorObjectWithCauseAndKind 

func NewErrorObjectWithCauseAndKind(message string, cause error, kind NativeErrorKind, irritants ...Value) *NativeError

NewErrorObjectWithCauseAndKind creates a new error object that wraps a Go error with a specific kind. R7RS §6.11: The kind determines which error predicate (file-error?, read-error?) matches.

func NewFileError 

func NewFileError(message string, irritants ...Value) *NativeError

NewFileError creates a new file error object with the given message and irritants. R7RS §6.11: file-error? predicate checks for errors during file operations.

func NewNativeError 

func NewNativeError(msg string) *NativeError

NewNativeError creates a new native error with the given message.

func NewReadError 

func NewReadError(message string, irritants ...Value) *NativeError

NewReadError creates a new read error object with the given message and irritants. R7RS §6.11: read-error? predicate checks for errors during reading.

func (*NativeError) Datum 

func (p *NativeError) Datum() error

Datum returns the underlying Go error, if any.

func (*NativeError) EqualTo 

func (p *NativeError) EqualTo(v Value) bool

EqualTo returns true if this error object is equal to the given value.

func (*NativeError) Error 

func (p *NativeError) Error() string

Error implements the error interface.

func (*NativeError) Irritants 

func (p *NativeError) Irritants() Value

Irritants returns the list of irritant objects.

func (*NativeError) IsFileError 

func (p *NativeError) IsFileError() bool

IsFileError returns true if this is a file error.

func (*NativeError) IsReadError 

func (p *NativeError) IsReadError() bool

IsReadError returns true if this is a read error.

func (*NativeError) IsVoid 

func (p *NativeError) IsVoid() bool

IsVoid returns true if this error object is nil.

func (*NativeError) Kind 

func (p *NativeError) Kind() NativeErrorKind

Kind returns the error kind for R7RS error predicates.

func (*NativeError) Message 

func (p *NativeError) Message() *String

Message returns the error message string.

func (*NativeError) SchemeString 

func (p *NativeError) SchemeString() string

SchemeString returns the Scheme string representation of this error object.

func (*NativeError) Unwrap 

func (p *NativeError) Unwrap() error

Unwrap returns the underlying Go error for errors.Unwrap compatibility.

type NativeErrorKind 

type NativeErrorKind int

NativeErrorKind represents the type of an error object for R7RS error predicates. 

const (
	// NativeErrorKindGeneric is a generic error (default).
	NativeErrorKindGeneric NativeErrorKind = iota
	// NativeErrorKindRead is a read error (from reading data).
	NativeErrorKindRead
	// NativeErrorKindFile is a file error (from file operations).
	NativeErrorKindFile
)

type Number 

type Number interface {
	Value
	Kind() NumericKind
	Add(Number) Number
	Subtract(Number) Number
	Multiply(Number) Number
	Divide(Number) (Number, error)
	Negate() Number
	Abs() Number
	ToExact() (Number, error)
	ToInexact() Number
	IsZero() bool
	IsExact() bool
	IsInteger() bool  // R7RS §6.2.6: is this an integer value?
	IsRational() bool // R7RS §6.2.6: is this a rational value?
	IsFinite() bool   // R7RS §6.2.6: is this a finite number?
	IsNaN() bool      // R7RS §6.2.6: is this NaN?
	LessThan(Number) bool
	Compare(Number) int
}

Number represents a numeric value in the Scheme numeric tower.

R7RS §6.2.1: Numbers form a tower: number ⊃ complex ⊃ real ⊃ rational ⊃ integer. All numeric types implement this interface for uniform arithmetic operations.

Error signaling

Arithmetic methods signal errors by panicking with a static sentinel error (e.g., werr.ErrDivisionByZero, werr.ErrNotANumber). This follows the same convention used by Go's math/big package, where (*big.Int).Div, (*big.Int).QuoRem, and (*big.Float).Quo all panic on division by zero, and mirrors Go's own runtime behavior for built-in integer division.

Divide returns (Number, error) so callers can propagate division-by-zero without panic/recover. All other arithmetic methods remain single-return because they cannot fail.

func Promote added in v1.5.0 

func Promote(n Number, target NumericKind) Number

Promote converts a Number to the target NumericKind using the lossless promoter table. Panics if no promotion path exists (indicates a bug in the promotion table — all reachable paths should be populated).

func Simplify 

func Simplify(n Number) Number

Simplify attempts to reduce a number to a simpler type without losing information.

Simplification rules: - BigComplex with zero imaginary → real part - Complex with zero imaginary → Float → possibly Integer - BigFloat that is an integer → BigInteger → possibly Integer - Float that is an integer → Integer - Rational that is an integer → BigInteger → possibly Integer - BigInteger that fits int64 → Integer

type NumericKind added in v1.5.0 

type NumericKind uint8

NumericKind identifies a concrete numeric type for dispatch table indexing.

Used by the receiver-centric dispatch tables in each numeric type file to replace 7-way type switches with O(1) array lookups.

ADDING A NEW NUMERIC TYPE requires updates in these locations:

  1. values/numeric_kind.go — add KindXxx constant (this file)
  2. values/xxx.go — new type file: implement Number interface, declare [numKinds] dispatch tables, register via init() calling makeXxxDispatch helpers
  3. values/promotion.go — add row/column in promotionTable and promoter, update NumberToFloat64, NumberToComplex128
  4. values/numeric_tower.go — update Simplify, ExactnessOf
  5. values/numeric_dispatch_test.go — add new dispatch tables to TestAllDispatchEntriesPopulated
  6. registry/helpers/value_conv.go — update ToComplex128, ToFloat64
  7. extensions/math/prim_conversion.go — update exact->inexact, number->string, etc.
  8. extensions/math/prim_complex.go — update make-rectangular, make-polar, etc.
  9. wile-goast/goast/mapper.go — (EXTERNAL REPO) update numberToAST if the type maps to a Go literal
  10. ffi.go — update schemeToReflectValue (line ~300)
  11. internal/parser/parser_number.go — if the type can be parsed from source
  12. registry/helpers/equality.go — update Eqv if the type has special eqv? semantics

The dispatch tables (item 2) are tested by TestAllDispatchEntriesPopulated. The type-switch functions (items 3-4, 6) are tested by TestTypeSwitchFunctionsHandleAllTypes. 

const (
	KindInteger NumericKind = iota
	KindBigInteger
	KindFloat
	KindBigFloat
	KindRational
	KindComplex
	KindBigComplex
)

func PromotionResultKind added in v1.5.0 

func PromotionResultKind(kindA, kindB NumericKind) NumericKind

PromotionResultKind returns the result type when operands of kindA and kindB are combined in an arithmetic operation. The result is the least upper bound (LUB) in the promotion lattice — symmetric and lossless.

type Once 

type Once struct {
	// contains filtered or unexported fields
}

Once wraps sync.Once for Scheme

func NewOnce 

func NewOnce() *Once

NewOnce creates a new Once

func (*Once) Do 

func (p *Once) Do(f func()) bool

Do calls the function only once Returns true if this call executed the function, false if it was already called

func (*Once) Done 

func (p *Once) Done() bool

Done returns true if Do has been called

func (*Once) EqualTo 

func (p *Once) EqualTo(v Value) bool

EqualTo returns true if the onces are the same object.

func (*Once) ID 

func (p *Once) ID() uint64

ID returns the Once's unique identifier

func (*Once) IsVoid 

func (p *Once) IsVoid() bool

IsVoid returns true if the once is nil.

func (*Once) SchemeString 

func (p *Once) SchemeString() string

SchemeString returns the Scheme representation of the once.

type Opaque added in v1.9.1 

type Opaque interface {
	OpaqueTag() string
}

Opaque marks a Value as opaque to Scheme code. Any Value type can opt in by implementing this single method. The opaque? predicate checks this interface (capability check, not type check).

type OpaqueValue added in v1.9.1 

type OpaqueValue struct {
	// contains filtered or unexported fields
}

OpaqueValue wraps an arbitrary Go object as a Scheme value. Construction is Go-only via NewOpaqueValue. The inner value is accessible only from Go via Unwrap.

func NewOpaqueValue added in v1.9.1 

func NewOpaqueValue(tag string, val any) *OpaqueValue

NewOpaqueValue creates a new opaque value with the given tag and inner value.

func (*OpaqueValue) EqualTo added in v1.9.1 

func (p *OpaqueValue) EqualTo(v Value) bool

EqualTo returns true only if both are the same object (identity equality).

func (*OpaqueValue) IsVoid added in v1.9.1 

func (p *OpaqueValue) IsVoid() bool

IsVoid returns true if this opaque value is nil.

func (*OpaqueValue) OpaqueTag added in v1.9.1 

func (p *OpaqueValue) OpaqueTag() string

OpaqueTag returns the tag string identifying this opaque value's kind.

func (*OpaqueValue) SchemeString added in v1.9.1 

func (p *OpaqueValue) SchemeString() string

SchemeString returns the Scheme representation of this opaque value.

func (*OpaqueValue) Unwrap added in v1.9.1 

func (p *OpaqueValue) Unwrap() any

Unwrap returns the inner Go value. Go-only — not exposed to Scheme.

type OutputPort 

type OutputPort interface {
	Port
	Write([]byte) (int, error)
	Flush() error
}

OutputPort represents a Scheme output port.

type Pair 

type Pair [2]Value

Pair represents a Scheme cons cell.

Initial algebra (Bird & de Moor 1997, Meijer et al. 1991). Proper lists are the initial algebra of a polynomial functor. 

List = μX. 1 + Value × X

Constructors:
  nil  : 1 → List          = EmptyList (emptyListType, not *Pair)
  cons : Value × List → List = NewCons(car, cdr)

Eliminator (catamorphism / fold):
  ForEach(f) applies f to each car, returns tail

Invariant: EmptyList is a separate Go type from *Pair. This encodes
  the two constructors as distinct injections: (pair? '()) → #f.
Constrains: IsList (must terminate — uses Floyd cycle detection),
  PairBlock (batch allocation optimization, does not change the algebra),
  all list-processing primitives (must handle both constructors).
Constrained by: Tuple interface (read-only view over both constructors).

See BIBLIOGRAPHY.md "Lists as Initial Algebras".

func NewCons 

func NewCons(car, cdr Value) *Pair

NewCons creates a new Pair with the given car and cdr Values.

func (*Pair) Append 

func (p *Pair) Append(vs Value) Value

Append appends the given Value vs to the end of the list represented by the Pair. It panics if the Pair does not represent a proper list.

R7RS §6.4: The resulting list is always newly allocated, except that it shares structure with the last argument. This implementation copies the spine of p and sets the last cdr to vs.

func (*Pair) AsVector 

func (p *Pair) AsVector() *Vector

AsVector converts the Pair representing a proper list into a Vector. It panics if the Pair does not represent a proper list.

Note: Uses context.Background() — see Length comment for circular list caveat.

func (*Pair) Car 

func (p *Pair) Car() Value

Car returns the car of the Pair.

func (*Pair) Cdr 

func (p *Pair) Cdr() Value

Cdr returns the cdr of the Pair.

func (*Pair) Datum 

func (p *Pair) Datum() [2]Value

Datum returns the underlying data of the Pair as a [2]Value array.

func (*Pair) EqualTo 

func (p *Pair) EqualTo(o Value) bool

EqualTo checks if the Pair is equal to another Value o. Delegates to the cycle-aware pairEqualToDeep to handle circular lists.

func (*Pair) ForEach 

func (p *Pair) ForEach(ctx context.Context, fn ForEachFunc) (Value, error)

ForEach iterates over each element in the list represented by the Pair. The provided function fn is called for each element with the index i, a boolean hasNext indicating if there are more elements, and the value v. If fn returns an error, the iteration stops and the error is returned. If the list ends with a non-empty cdr, that cdr is returned as the second return value.

func (*Pair) IsEmptyList 

func (p *Pair) IsEmptyList() bool

IsEmptyList returns false. A *Pair is never the empty list; EmptyList is a separate emptyListType value.

func (*Pair) IsList 

func (p *Pair) IsList() bool

IsList checks if the Pair represents a proper list. Uses Floyd's cycle detection (tortoise-and-hare) to handle circular lists. Returns false for circular lists per R7RS §6.4. See BIBLIOGRAPHY.md "Floyd's Cycle Detection".

Implementation note: This method must use *Pair (not Tuple) for cycle detection because it requires pointer identity comparison (slow == fast). Interfaces cannot be compared by pointer identity.

func (*Pair) IsVoid 

func (p *Pair) IsVoid() bool

IsVoid checks if the Pair is void (nil).

func (*Pair) Length 

func (p *Pair) Length() int

Length returns the length of the list represented by the Pair. It panics if the Pair does not represent a proper list.

Note: Uses context.Background() — no cancellation path. ForEach has no cycle detection, so a circular list will hang indefinitely. Callers must ensure the receiver is a proper list (e.g., via IsList).

func (*Pair) SchemeString 

func (p *Pair) SchemeString() string

SchemeString returns the Scheme representation of the Pair. Handles circular structures (from datum labels or set-cdr!/set-car!) by emitting "..." when a cycle is detected.

func (*Pair) SetCar 

func (p *Pair) SetCar(v Value)

SetCar sets the car of the Pair to the given Value v.

func (*Pair) SetCdr 

func (p *Pair) SetCdr(v Value)

SetCdr sets the cdr of the Pair to the given Value v.

func (*Pair) String 

func (p *Pair) String() string

String returns the string representation of the Pair. Handles circular structures (from datum labels or set-cdr!/set-car!) by emitting "..." when a cycle is detected.

type PairBlock added in v1.5.0 

type PairBlock []Pair

PairBlock is a contiguous slice of Pairs that can be linked into a proper list. Block allocation amortizes N heap allocations to 1 for list construction.

func (PairBlock) LinkWith added in v1.5.0 

func (b PairBlock) LinkWith(vs []Value) Tuple

LinkWith fills cars from vs and links cdrs into a proper list, returning the head as a Tuple. The block must have the same length as vs. A nil or empty block returns EmptyList.

type Port 

type Port interface {
	Value
	Close() error
	IsClosed() bool
}

Port represents a Scheme I/O port.

R7RS §6.13: All port types support close and open-state queries.

type Process added in v1.9.1 

type Process struct {
	// contains filtered or unexported fields
}

Process represents a running OS process. Wraps *exec.Cmd and its connected pipes. Accessors return the ports for stdout, stderr, and stdin.

func NewProcess added in v1.9.1 

func NewProcess(
	command string,
	cmd *exec.Cmd,
	stdin *CharacterOutputPort,
	stdout *CharacterInputPort,
	stderr *CharacterInputPort,
) *Process

NewProcess creates a Process value. The cmd may be nil for testing. Ports may be nil if the process was not started with pipes.

func (*Process) Cmd added in v1.9.1 

func (p *Process) Cmd() *exec.Cmd

Cmd returns the underlying *exec.Cmd.

func (*Process) Command added in v1.9.1 

func (p *Process) Command() string

Command returns the command name.

func (*Process) EqualTo added in v1.9.1 

func (p *Process) EqualTo(v Value) bool

EqualTo returns true only for identity (same pointer).

func (*Process) IsVoid added in v1.9.1 

func (p *Process) IsVoid() bool

IsVoid reports whether this process value is void. A nil *Process is considered void to satisfy the values.Value contract.

func (*Process) SchemeString added in v1.9.1 

func (p *Process) SchemeString() string

SchemeString returns the Scheme external representation.

func (*Process) Stderr added in v1.9.1 

func (p *Process) Stderr() *CharacterInputPort

Stderr returns the input port connected to the process stderr.

func (*Process) Stdin added in v1.9.1 

func (p *Process) Stdin() *CharacterOutputPort

Stdin returns the output port connected to the process stdin.

func (*Process) Stdout added in v1.9.1 

func (p *Process) Stdout() *CharacterInputPort

Stdout returns the input port connected to the process stdout.

type Promise 

type Promise struct {
	// contains filtered or unexported fields
}

Promise represents a delayed computation (R7RS lazy evaluation). A promise contains either an unevaluated thunk or a cached result.

R7RS §4.2.5: The first time a promise is forced, its body is evaluated and the result is memoized; on subsequent forces, the memoized result is returned.

func NewForcedPromise 

func NewForcedPromise(value Value) *Promise

NewForcedPromise creates an already-forced promise with the given value. This is used by make-promise when given a non-promise value.

func NewPromise 

func NewPromise(thunk Callable) *Promise

NewPromise creates a new unforced promise with the given thunk. The thunk should be a procedure that takes no arguments.

func (*Promise) CachedResult added in v1.5.0 

func (p *Promise) CachedResult() Value

CachedResult returns the memoized result of a forced promise. Only valid when IsForced returns true.

func (*Promise) EqualTo 

func (p *Promise) EqualTo(v Value) bool

EqualTo returns true if the promises are the same object.

func (*Promise) Force added in v1.5.0 

func (p *Promise) Force(result Value)

Force transitions the promise from unforced to forced, caching the given result and clearing the thunk. Subsequent calls to IsForced return true and CachedResult returns the cached value.

func (*Promise) IsForced added in v1.5.0 

func (p *Promise) IsForced() bool

IsForced reports whether the promise has been forced. A forced promise has a cached result and no thunk.

func (*Promise) IsVoid 

func (p *Promise) IsVoid() bool

IsVoid returns true if the promise is nil.

func (*Promise) SchemeString 

func (p *Promise) SchemeString() string

SchemeString returns the Scheme representation of the promise.

func (*Promise) Thunk 

func (p *Promise) Thunk() Callable

Thunk returns the unevaluated procedure. Returns nil when the promise has been forced.

type RWMutex 

type RWMutex struct {
	// contains filtered or unexported fields
}

RWMutex wraps sync.RWMutex for Scheme

func NewRWMutex 

func NewRWMutex(name string) *RWMutex

NewRWMutex creates a new RWMutex

func (*RWMutex) EqualTo 

func (p *RWMutex) EqualTo(v Value) bool

EqualTo returns true if the RWMutexes are the same object.

func (*RWMutex) ID 

func (p *RWMutex) ID() uint64

ID returns the RWMutex's unique identifier

func (*RWMutex) IsVoid 

func (p *RWMutex) IsVoid() bool

IsVoid returns true if the RWMutex is nil.

func (*RWMutex) Lock 

func (p *RWMutex) Lock()

Lock acquires the write lock

func (*RWMutex) Name 

func (p *RWMutex) Name() string

Name returns the RWMutex's name

func (*RWMutex) RLock 

func (p *RWMutex) RLock()

RLock acquires the read lock

func (*RWMutex) RUnlock 

func (p *RWMutex) RUnlock()

RUnlock releases the read lock

func (*RWMutex) SchemeString 

func (p *RWMutex) SchemeString() string

SchemeString returns the Scheme representation of the RWMutex.

func (*RWMutex) TryLock 

func (p *RWMutex) TryLock() bool

TryLock tries to acquire the write lock without blocking

func (*RWMutex) TryRLock 

func (p *RWMutex) TryRLock() bool

TryRLock tries to acquire the read lock without blocking

func (*RWMutex) Unlock 

func (p *RWMutex) Unlock()

Unlock releases the write lock

type Rational 

type Rational struct {
	// contains filtered or unexported fields
}

Rational represents a Scheme rational number (exact fraction).

func NewRational 

func NewRational(num, denom int64) *Rational

NewRational creates a new Rational from numerator and denominator. The fraction is automatically normalized (reduced to lowest terms).

func NewRationalFromBigInt 

func NewRationalFromBigInt(num, denom *big.Int) *Rational

NewRationalFromBigInt creates a new Rational from big.Int numerator and denominator.

func NewRationalFromRat 

func NewRationalFromRat(r *big.Rat) *Rational

NewRationalFromRat creates a Rational from an existing big.Rat.

func (*Rational) Abs added in v1.1.0 

func (p *Rational) Abs() Number

Abs returns the absolute value of this rational.

func (*Rational) Add 

func (p *Rational) Add(o Number) Number

R7RS §6.2.6: The + procedure returns the sum of its arguments. R7RS §6.2.2 Exactness: exact + exact = exact, exact + inexact = inexact. Inexactness is contagious per R7RS §6.2.2.

func (*Rational) Compare 

func (p *Rational) Compare(o Number) int

Compare compares this rational with another number.

R7RS §6.2.6: Numeric comparisons use mathematical value regardless of exactness. Returns -1 if p < o, 0 if p == o, 1 if p > o.

func (*Rational) Denom 

func (p *Rational) Denom() *big.Int

Denom returns the denominator as a big.Int.

func (*Rational) DenomInt64 

func (p *Rational) DenomInt64() int64

DenomInt64 returns the denominator as int64 (may overflow for large values).

func (*Rational) Divide 

func (p *Rational) Divide(o Number) (Number, error)

Divide returns the quotient of two numbers.

func (*Rational) EqualTo 

func (p *Rational) EqualTo(v Value) bool

EqualTo returns true if the rationals have equal values. Handles comparison with Integer and BigInteger for symmetry with whole-valued rationals (e.g., 5/1 == 5).

func (*Rational) Float64 

func (p *Rational) Float64() float64

Float64 returns the rational as a float64 approximation.

func (*Rational) HashCode 

func (p *Rational) HashCode() uint64

HashCode returns a hash of the rational value. Uses the canonical exact-family hash so that Integer, BigInteger, and Rational produce identical hashes for equal values.

func (*Rational) IsExact 

func (p *Rational) IsExact() bool

IsExact returns true since Rational is always exact.

R7RS §6.2.2: Rationals are always exact numbers.

func (*Rational) IsFinite added in v1.1.0 

func (p *Rational) IsFinite() bool

IsFinite returns true since exact rationals are always finite.

R7RS §6.2.6: finite? returns #t for all exact numbers.

func (*Rational) IsInteger 

func (p *Rational) IsInteger() bool

IsInteger returns true if the rational represents an integer (denominator is 1).

func (*Rational) IsNaN added in v1.1.0 

func (p *Rational) IsNaN() bool

IsNaN returns false since exact rationals are never NaN.

R7RS §6.2.6: nan? returns #f for exact numbers.

func (*Rational) IsNegative added in v1.1.0 

func (p *Rational) IsNegative() bool

IsNegative returns true if this rational is negative.

func (*Rational) IsPositive added in v1.1.0 

func (p *Rational) IsPositive() bool

IsPositive returns true if this rational is positive.

func (*Rational) IsRational added in v1.1.0 

func (p *Rational) IsRational() bool

IsRational returns true since Rational is always a rational number.

R7RS §6.2.6: rational? returns #t for exact rationals.

func (*Rational) IsVoid 

func (p *Rational) IsVoid() bool

IsVoid returns true if the rational is nil.

func (*Rational) IsZero 

func (p *Rational) IsZero() bool

IsZero returns true if the rational equals zero.

func (*Rational) Kind added in v1.5.0 

func (p *Rational) Kind() NumericKind

Add returns the sum of two numbers.

Kind returns the numeric kind for dispatch table indexing.

func (*Rational) LessThan 

func (p *Rational) LessThan(o Number) bool

LessThan returns true if this rational is less than another number.

func (*Rational) Multiply 

func (p *Rational) Multiply(o Number) Number

Multiply returns the product of two numbers.

func (*Rational) Negate 

func (p *Rational) Negate() Number

Negate returns the negation of this rational.

R7RS §6.2.6: The - procedure with one argument returns the additive inverse.

func (*Rational) Num 

func (p *Rational) Num() *big.Int

Num returns the numerator as a big.Int.

func (*Rational) NumInt64 

func (p *Rational) NumInt64() int64

NumInt64 returns the numerator as int64 (may overflow for large values).

func (*Rational) Rat 

func (p *Rational) Rat() *big.Rat

Rat returns the underlying big.Rat value.

func (*Rational) SchemeString 

func (p *Rational) SchemeString() string

SchemeString returns the Scheme representation of the rational.

func (*Rational) Sign added in v1.1.0 

func (p *Rational) Sign() int

Sign returns -1 if negative, 0 if zero, or 1 if positive.

func (*Rational) Subtract 

func (p *Rational) Subtract(o Number) Number

Subtract returns the difference of two numbers.

R7RS §6.2.6: The - procedure returns the difference of its arguments. R7RS §6.2.2 Exactness: exact - exact = exact, exact - inexact = inexact.

func (*Rational) ToExact added in v1.1.0 

func (p *Rational) ToExact() (Number, error)

ToExact returns this Rational unchanged since it is already exact.

R7RS §6.2.6: exact returns an exact representation of its argument.

func (*Rational) ToInexact added in v1.1.0 

func (p *Rational) ToInexact() Number

ToInexact converts this Rational to an inexact BigFloat.

R7RS §6.2.6: inexact returns an inexact representation of its argument. L18: Use big.Float.SetRat to preserve precision for large rationals.

type RealNumber added in v1.1.0 

type RealNumber interface {
	Number
	IsPositive() bool
	IsNegative() bool
	Sign() int
}

RealNumber represents a real-valued number with sign operations.

R7RS §6.2.6: The positive? and negative? predicates apply only to real numbers. Sign returns -1, 0, or 1.

type Record 

type Record struct {
	// contains filtered or unexported fields
}

Record represents a record instance as defined by R7RS define-record-type. Each record has a type descriptor and a slice of field values.

func NewRecord 

func NewRecord(rt *RecordType, fields []Value) *Record

NewRecord creates a new Record with the given type and field values. The fields slice should have the same length as the record type's field count.

func (*Record) EqualTo 

func (p *Record) EqualTo(v Value) bool

EqualTo implements structural equality for records. Two records are equal if they have the same type and all fields are equal.

func (*Record) Field 

func (p *Record) Field(index int) Value

Field returns the value at the given field index.

func (*Record) FieldByName 

func (p *Record) FieldByName(name *Symbol) Value

FieldByName returns the value of the field with the given name. Returns nil if the field is not found.

func (*Record) IsVoid 

func (p *Record) IsVoid() bool

IsVoid returns true if the record is nil.

func (*Record) RecordType 

func (p *Record) RecordType() *RecordType

RecordType returns the record's type descriptor.

func (*Record) SchemeString 

func (p *Record) SchemeString() string

SchemeString returns the Scheme external representation of the record.

func (*Record) SetField 

func (p *Record) SetField(index int, value Value)

SetField sets the value at the given field index.

func (*Record) SetFieldByName 

func (p *Record) SetFieldByName(name *Symbol, value Value)

SetFieldByName sets the value of the field with the given name. Does nothing if the field is not found.

type RecordType 

type RecordType struct {
	// contains filtered or unexported fields
}

RecordType represents a record type descriptor as defined by R7RS define-record-type. It holds the type name, the ordered list of field names, and an optional parent type for record inheritance.

func NewDerivedRecordType added in v1.12.0 

func NewDerivedRecordType(name *Symbol, parent *RecordType, fieldNames []*Symbol) *RecordType

NewDerivedRecordType creates a new RecordType that inherits from the given parent.

func NewRecordType 

func NewRecordType(name *Symbol, fieldNames []*Symbol) *RecordType

NewRecordType creates a new RecordType with the given name and field names. The parent defaults to nil (no inheritance).

func (*RecordType) EqualTo 

func (p *RecordType) EqualTo(v Value) bool

EqualTo implements identity-based equality for record types. Two record types are equal only if they are the same object.

func (*RecordType) FieldCount 

func (p *RecordType) FieldCount() int

FieldCount returns the number of fields in this record type.

func (*RecordType) FieldIndex 

func (p *RecordType) FieldIndex(name *Symbol) int

FieldIndex returns the index of the field with the given name, or -1 if not found.

func (*RecordType) FieldNames 

func (p *RecordType) FieldNames() []*Symbol

FieldNames returns the ordered list of field name symbols.

func (*RecordType) IsVoid 

func (p *RecordType) IsVoid() bool

IsVoid returns true if the record type is nil.

func (*RecordType) Name 

func (p *RecordType) Name() *Symbol

Name returns the record type's name symbol.

func (*RecordType) Parent added in v1.12.0 

func (p *RecordType) Parent() *RecordType

Parent returns the parent record type, or nil if this is a base type.

func (*RecordType) SchemeString 

func (p *RecordType) SchemeString() string

SchemeString returns the Scheme external representation of the record type.

type RecordTypeConstraint added in v1.12.0 

type RecordTypeConstraint struct {
	// contains filtered or unexported fields
}

RecordTypeConstraint validates that a value is a Record whose RecordType matches (or inherits from) a specific record type descriptor.

func NewRecordTypeConstraint added in v1.12.0 

func NewRecordTypeConstraint(rtd *RecordType) *RecordTypeConstraint

NewRecordTypeConstraint creates a RecordTypeConstraint for the given record type descriptor. Panics if rtd is nil.

func (*RecordTypeConstraint) Check added in v1.12.0 

func (p *RecordTypeConstraint) Check(v Value) (any, bool, error)

Check tests whether v is a Record whose type matches (or inherits from) the target record type descriptor. Walks the parent chain for subtype matching.

func (*RecordTypeConstraint) Description added in v1.12.0 

func (p *RecordTypeConstraint) Description() string

Description returns a human-readable description of the record type constraint.

func (*RecordTypeConstraint) Name added in v1.12.0 

func (p *RecordTypeConstraint) Name() string

Name returns the Scheme-facing name of the record type.

type SchemeWriter 

type SchemeWriter struct {
	// contains filtered or unexported fields
}

SchemeWriter provides cycle-aware writing of Scheme values. Two-pass datum label output (R7RS §2.4): pass 1 (findShared) traverses the value graph to identify multiply-referenced objects; pass 2 (write) emits #n= definitions on first encounter and #n# references thereafter. See BIBLIOGRAPHY.md "Two-Pass Datum Label Output".

Implementation note: Uses maps with concrete *Pair and *Vector keys (not Tuple/Indexable interfaces) because: 1. Go map keys must be comparable types - interfaces are not suitable 2. Cycle/sharing detection requires pointer identity tracking 3. Each concrete type needs separate tracking for proper label assignment

func NewSchemeWriter 

func NewSchemeWriter() *SchemeWriter

NewSchemeWriter creates a new SchemeWriter for cycle-aware output. Default mode is WriteModeWrite (labels only circular references).

func (*SchemeWriter) WriteString 

func (p *SchemeWriter) WriteString(v Value) string

WriteString writes a Scheme value to a string with cycle detection. Circular and shared structures are represented using datum labels.

type SelectCase 

type SelectCase struct {
	Channel *Channel
	Value   Value // for send operations
	Kind    SelectCaseKind
}

type SelectCaseKind added in v1.5.0 

type SelectCaseKind int

SelectCase represents a case in a channel select operation SelectCaseKind distinguishes the three valid select case types. 

const (
	SelectReceive SelectCaseKind = iota
	SelectSend
	SelectDefault
)

type SourceLocation 

type SourceLocation interface {
	Value
	Index() int
	Column() int
	Line() int
}

SourceLocation represents a position in source code.

type String 

type String struct {
	Value string
	// contains filtered or unexported fields
}

String represents a Scheme string value. R7RS §6.7: Literal strings and strings from symbol->string are immutable.

func NewMutableString 

func NewMutableString(str string) *String

NewMutableString returns a mutable String value. Use this for strings that may be mutated (e.g., via string-set! or string-fill!). R7RS §6.7: Procedures like string-copy return mutable strings.

func NewString 

func NewString(str string) *String

NewString returns an immutable String value. R7RS §6.7: Literal strings and strings from symbol->string are immutable. Use NewMutableString for runtime-allocated strings that may be mutated.

func (*String) Datum 

func (p *String) Datum() string

Datum returns the underlying string value.

func (*String) EqualTo 

func (p *String) EqualTo(v Value) bool

EqualTo returns true if the strings have equal values.

func (*String) Fill 

func (p *String) Fill(char rune, start, end int) error

Fill fills the string (or a portion of it) with the given character. Returns an error if the string is immutable. R7RS §6.7: (string-fill! string fill [start [end]])

func (*String) Get added in v1.1.0 

func (p *String) Get(i int) Value

Get returns the character at the given rune index as a Character value.

R7RS §6.7: (string-ref string k) returns character k of string.

func (*String) HashCode 

func (p *String) HashCode() uint64

HashCode returns a hash of the string value.

func (*String) IsImmutable added in v1.3.0 

func (p *String) IsImmutable() bool

IsImmutable returns true if the string cannot be mutated. Literal strings and strings returned by symbol->string are immutable. R7RS §6.7: It is an error to apply mutation procedures to literal strings or strings returned by symbol->string.

func (*String) IsVoid 

func (p *String) IsVoid() bool

IsVoid returns true if the string is nil.

func (*String) Len 

func (p *String) Len() int

Len returns the length of the string in characters (runes).

func (*String) Length added in v1.1.0 

func (p *String) Length() int

Length returns the length of the string in characters (runes).

R7RS §6.7: (string-length string) returns the number of characters.

func (*String) Runes 

func (p *String) Runes() []rune

Runes returns the string as a slice of runes.

func (*String) SchemeString 

func (p *String) SchemeString() string

SchemeString returns the Scheme representation of the string.

func (*String) Set added in v1.1.0 

func (p *String) Set(i int, v Value) error

Set sets the character at the given rune index from a Character value. Returns an error if the string is immutable.

R7RS §6.7: (string-set! string k char) stores char in element k.

func (*String) SetChar 

func (p *String) SetChar(k int, char rune) error

SetChar sets the character at index k to the given rune. Returns an error if the string is immutable.

R7RS §6.7: (string-set! string k char) R7RS §6.7: "It is an error" to mutate literal strings or strings returned by symbol->string. This implementation signals an error when mutation is attempted on immutable strings.

func (*String) SetValue 

func (p *String) SetValue(s string) error

SetValue sets the entire string value. Returns an error if the string is immutable.

func (*String) String 

func (p *String) String() string

type StringInputPort 

type StringInputPort struct {
	// contains filtered or unexported fields
}

StringInputPort represents a Scheme string output port backed by a buffer.

func NewStringInputPortWithBuffer 

func NewStringInputPortWithBuffer(buffer *bytes.Buffer) *StringInputPort

NewStringInputPortWithBuffer creates a new string output port.

func (*StringInputPort) Close 

func (p *StringInputPort) Close() error

Close marks the port as closed and, if a closer was provided, closes the underlying stream. Close is idempotent.

func (*StringInputPort) Datum 

func (p *StringInputPort) Datum() *bytes.Buffer

Datum returns the underlying buffer.

func (*StringInputPort) EqualTo 

func (p *StringInputPort) EqualTo(v Value) bool

EqualTo returns true if v is a port with the same kind and datum identity. This works because Go's any equality checks both dynamic type and value, so two ports sharing a kind but using different backing types (e.g., *bufio.Writer vs *bytes.Buffer) will never compare equal.

func (*StringInputPort) Flush 

func (p *StringInputPort) Flush() error

func (*StringInputPort) IsClosed 

func (p *StringInputPort) IsClosed() bool

IsClosed returns true if the port has been closed.

func (*StringInputPort) IsVoid 

func (p *StringInputPort) IsVoid() bool

IsVoid returns true if the port is nil.

func (*StringInputPort) Read 

func (p *StringInputPort) Read(bs []byte) (int, error)

Read reads data from the port into bs.

func (*StringInputPort) ReadRune 

func (p *StringInputPort) ReadRune() (rune, int, error)

ReadRune reads a rune from the port.

func (*StringInputPort) SchemeString 

func (p *StringInputPort) SchemeString() string

SchemeString returns the Scheme external representation of the port.

func (*StringInputPort) String 

func (p *StringInputPort) String() string

func (*StringInputPort) UnreadRune 

func (p *StringInputPort) UnreadRune() error

UnreadRune unreads the last rune read from the port.

type StringOutputPort 

type StringOutputPort struct {
	// contains filtered or unexported fields
}

StringOutputPort represents a Scheme string output port backed by a buffer.

func NewStringOutputPort 

func NewStringOutputPort() *StringOutputPort

NewStringOutputPort creates a new string output port.

func NewStringOutputPortWithBuffer 

func NewStringOutputPortWithBuffer(buffer *bytes.Buffer) *StringOutputPort

NewStringOutputPortWithBuffer creates a new string output port.

func (*StringOutputPort) Close 

func (p *StringOutputPort) Close() error

Close marks the port as closed and, if a closer was provided, closes the underlying stream. Close is idempotent.

func (*StringOutputPort) Datum 

func (p *StringOutputPort) Datum() *bytes.Buffer

Datum returns the underlying buffer.

func (*StringOutputPort) EqualTo 

func (p *StringOutputPort) EqualTo(v Value) bool

EqualTo returns true if v is a port with the same kind and datum identity. This works because Go's any equality checks both dynamic type and value, so two ports sharing a kind but using different backing types (e.g., *bufio.Writer vs *bytes.Buffer) will never compare equal.

func (*StringOutputPort) Flush 

func (p *StringOutputPort) Flush() error

Flush is a no-op for StringOutputPort.

func (*StringOutputPort) IsClosed 

func (p *StringOutputPort) IsClosed() bool

IsClosed returns true if the port has been closed.

func (*StringOutputPort) IsVoid 

func (p *StringOutputPort) IsVoid() bool

IsVoid returns true if the port is nil.

func (*StringOutputPort) SchemeString 

func (p *StringOutputPort) SchemeString() string

SchemeString returns the Scheme external representation of the port.

func (*StringOutputPort) String 

func (p *StringOutputPort) String() string

func (*StringOutputPort) Write 

func (p *StringOutputPort) Write(bs []byte) (int, error)

Write writes data to the port.

func (*StringOutputPort) WriteRune 

func (p *StringOutputPort) WriteRune(rn rune) (int, error)

WriteRune writes a single rune to the port's buffer.

func (*StringOutputPort) WriteString 

func (p *StringOutputPort) WriteString(s string) (int, error)

WriteString writes a string to the port.

type Symbol 

type Symbol struct {
	Key string
}

Symbol represents a Scheme symbol.

func NewSymbol 

func NewSymbol(key string) *Symbol

NewSymbol creates a new symbol with the given key.

func NewTemporaryVariableName 

func NewTemporaryVariableName() *Symbol

NewTemporaryVariableName generates a unique symbol for use as a temporary variable. The symbol name has the format "__T_<base32-encoded-random-bytes>". Uses 128 bits of cryptographic randomness to ensure uniqueness. Thread-safe: uses crypto/rand which is safe for concurrent use. Panics if random number generation fails.

func (*Symbol) Copy 

func (p *Symbol) Copy() Value

Copy returns a copy of the symbol.

func (*Symbol) Datum 

func (p *Symbol) Datum() string

Datum returns the symbol's key string.

func (*Symbol) EqualTo 

func (p *Symbol) EqualTo(v Value) bool

EqualTo returns true if the symbols have equal keys.

func (*Symbol) HashCode 

func (p *Symbol) HashCode() uint64

HashCode returns a hash of the symbol's key.

func (*Symbol) IsVoid 

func (p *Symbol) IsVoid() bool

IsVoid returns true if the symbol is nil.

func (*Symbol) SchemeString 

func (p *Symbol) SchemeString() string

SchemeString returns the R7RS external representation of the symbol.

R7RS §7.1.1: Identifiers that can be represented without bars are written bare. Otherwise, they are enclosed in vertical bars with only \ and | characters escaped.

type TerminatedThreadException 

type TerminatedThreadException struct {
	Thread *Thread
}

TerminatedThreadException is raised when joining a terminated thread

func (*TerminatedThreadException) Error 

func (p *TerminatedThreadException) Error() string

type TextualReader 

type TextualReader interface {
	InputPort
	ReadRune() (rune, int, error)
	UnreadRune() error
}

TextualReader represents a textual input port capable of rune-level I/O.

R7RS §6.13.2: Textual input ports support read-char, peek-char, read-line, etc.

type TextualWriter 

type TextualWriter interface {
	OutputPort
	WriteRune(rune) (int, error)
}

TextualWriter represents a textual output port capable of rune-level I/O.

R7RS §6.13.3: Textual output ports support write-char, write-string, etc.

type Thread 

type Thread struct {

	// RunFunc is set by the machine package to actually run the thread
	// This avoids circular dependency between values and machine
	RunFunc func(ctx context.Context, thunk Callable) (Value, error)

	// CleanupFunc is injected by the machine package to run dynamic-wind
	// after thunks (UnwindTo(0)) on thread exit. Called on both normal exit
	// and forced termination.
	CleanupFunc func()
	// contains filtered or unexported fields
}

Thread represents a Scheme thread (SRFI-18)

func NewThread 

func NewThread(thunk Callable, name string) *Thread

NewThread creates a new thread that will execute the given thunk.

func (*Thread) AbandonOwnedMutexes added in v1.1.0 

func (p *Thread) AbandonOwnedMutexes()

AbandonOwnedMutexes marks all mutexes owned by this thread as abandoned. Called during thread termination to ensure waiting threads are notified.

func (*Thread) Context added in v1.5.0 

func (p *Thread) Context() context.Context

Context returns the context associated with this thread. Returns nil if the thread has not been started.

func (*Thread) Done 

func (p *Thread) Done() <-chan struct{}

Done returns a channel that's closed when the thread terminates

func (*Thread) EqualTo 

func (p *Thread) EqualTo(v Value) bool

EqualTo returns true if both threads are the same object.

func (*Thread) ID 

func (p *Thread) ID() uint64

ID returns the thread's unique identifier

func (*Thread) IsVoid 

func (p *Thread) IsVoid() bool

IsVoid returns true if this thread is nil.

func (*Thread) Join 

func (p *Thread) Join(timeout *time.Duration) (Value, error)

Join waits for the thread to terminate with optional timeout Returns the thread's result or an error

func (*Thread) Name 

func (p *Thread) Name() string

Name returns the thread's name

func (*Thread) SchemeString 

func (p *Thread) SchemeString() string

SchemeString returns the Scheme representation of this thread.

func (*Thread) SetSpecific 

func (p *Thread) SetSpecific(v Value)

SetSpecific sets the thread's specific field

func (*Thread) Sleep 

func (p *Thread) Sleep(d time.Duration)

Sleep pauses the thread for the given duration

func (*Thread) Specific 

func (p *Thread) Specific() Value

Specific returns the thread's specific field (thread-local storage)

func (*Thread) Start 

func (p *Thread) Start(parentCtx context.Context) error

Start begins execution of the thread. The parentCtx is used as the parent for the thread's cancellable context, enabling cancellation propagation from the engine/caller while allowing independent termination via thread-terminate!.

func (*Thread) State 

func (p *Thread) State() ThreadState

State returns the current state of the thread

func (*Thread) StateSymbol 

func (p *Thread) StateSymbol() *Symbol

StateSymbol returns the state as a Scheme symbol. Returns package-level singletons so that repeated calls return the same pointer: (eq? (thread-state t) (thread-state t)) → #t. See the doc comment on SymbolThreadNew for eq? vs equal? caveats.

func (*Thread) Terminate 

func (p *Thread) Terminate()

Terminate forcefully terminates the thread. Marks all owned mutexes as abandoned and cancels the thread's context. The deferred cleanup in the goroutine (dynamic-wind after thunks) will fire when the goroutine exits. However, AbandonOwnedMutexes is also called here directly because the goroutine may be blocked on a Go-level operation (e.g., sync.Cond.Wait) and won't exit immediately on context cancellation.

func (*Thread) TrackMutex added in v1.1.0 

func (p *Thread) TrackMutex(m *Mutex)

TrackMutex adds a mutex to this thread's ownership tracking set. Called by mutex-lock! when a mutex is acquired with this thread as owner.

func (*Thread) UntrackMutex added in v1.1.0 

func (p *Thread) UntrackMutex(m *Mutex)

UntrackMutex removes a mutex from this thread's ownership tracking set. Called by mutex-unlock! when a mutex is released.

func (*Thread) Yield 

func (p *Thread) Yield()

Yield yields execution to other threads

type ThreadState 

type ThreadState int

ThreadState represents the state of a thread 

const (
	ThreadNew        ThreadState = iota // Created but not started
	ThreadRunnable                      // Running or ready to run
	ThreadBlocked                       // Waiting for mutex/cv/sleep
	ThreadTerminated                    // Finished execution
)

ThreadState constants.

func (ThreadState) String 

func (p ThreadState) String() string

type Time 

type Time struct {
	// contains filtered or unexported fields
}

Time represents a point in time (SRFI-18)

func CurrentTime 

func CurrentTime() *Time

CurrentTime returns the current time

func NewTime 

func NewTime(t time.Time) *Time

NewTime creates a new Time from a Go time.Time

func NewTimeFromSeconds 

func NewTimeFromSeconds(seconds float64) *Time

NewTimeFromSeconds creates a Time from seconds since epoch

func (*Time) Add 

func (p *Time) Add(d time.Duration) *Time

Add returns a new Time that is the given duration after this time

func (*Time) After 

func (p *Time) After(other *Time) bool

After returns true if this time is after another

func (*Time) Before 

func (p *Time) Before(other *Time) bool

Before returns true if this time is before another

func (*Time) DurationFromNow 

func (p *Time) DurationFromNow() time.Duration

DurationFromNow returns the duration from now until this time.

func (*Time) EqualTo 

func (p *Time) EqualTo(v Value) bool

EqualTo returns true if both times represent the same instant.

func (*Time) GoTime 

func (p *Time) GoTime() time.Time

GoTime returns the underlying Go time.Time

func (*Time) IsVoid 

func (p *Time) IsVoid() bool

IsVoid returns true if the time is nil.

func (*Time) SchemeString 

func (p *Time) SchemeString() string

SchemeString returns the Scheme representation of the time.

func (*Time) Seconds 

func (p *Time) Seconds() float64

Seconds returns the time as seconds since the epoch

func (*Time) Sub 

func (p *Time) Sub(other *Time) time.Duration

Sub returns the duration between this time and another

type Tuple 

type Tuple interface {
	Value
	// Car returns the first element of the pair (R7RS §6.4).
	Car() Value
	// Cdr returns the rest of the list after the first element (R7RS §6.4).
	Cdr() Value
	// ForEach calls fn for each element in order. Returns the tail value
	// (EmptyList for proper lists, the improper cdr otherwise).
	ForEach(ctx context.Context, fn ForEachFunc) (Value, error)
	// Length returns the number of elements. For improper lists, this
	// counts only the proper prefix.
	Length() int
	// Append creates a new list with value appended (R7RS §6.4 append).
	Append(value Value) Value
	// AsVector converts the list to a Vector (R7RS §6.4 list->vector).
	AsVector() *Vector
	// IsList reports whether this is a proper list (R7RS §6.4 list?).
	// Uses Floyd's cycle detection (tortoise-and-hare).
	IsList() bool
	// IsEmptyList reports whether this is the empty list (R7RS §6.4 null?).
	IsEmptyList() bool
	// IsVoid reports whether this value is void (nil receiver handling).
	IsVoid() bool
}

Tuple represents the Scheme list protocol — any value that can be consumed as a sequence of car/cdr pairs.

R7RS §6.4: Lists are chains of pairs terminated by the empty list. Tuple captures the operations needed to traverse, measure, and convert list-shaped values without requiring a concrete *Pair type.

Implemented by: Pair, emptyListType (EmptyList singleton).

IsVoid is listed explicitly because Pair uses a nil-receiver convention where (*Pair)(nil) represents void, and the method must be dispatched through the interface to handle that case. 

var (

	// EmptyList is the singleton empty list ().
	// It implements Tuple but is not *Pair, enforcing (pair? '()) -> #f
	// at the type level per R7RS 6.4.
	EmptyList Tuple = emptyListType{}
)

func List 

func List(os ...Value) Tuple

List constructs a proper list from the given values. Returns EmptyList if no arguments are provided. The resulting list has the values in the same order as the arguments.

Implementation note: Block-allocates all Pair cells in a single slice and links them via cdr pointers. Callers receive the Tuple interface.

func VectorToList 

func VectorToList(vs *Vector) Tuple

VectorToList converts a Vector to a proper list preserving element order. Returns EmptyList for nil or void vectors.

type TypeConstraint added in v1.12.0 

type TypeConstraint interface {
	// Name returns the Scheme-facing type name (e.g., "integer", "point").
	Name() string
	// Description returns a human-readable description.
	Description() string
	// Check tests whether v satisfies this constraint.
	// On success, returns the narrowed value and true.
	// On failure, returns nil, false, and an error describing the mismatch.
	Check(Value) (any, bool, error)
}

TypeConstraint describes a type expectation for documentation and validation. Built-in types are represented by ValueType constants. User-defined types (e.g., record types) implement this interface directly.

A nil TypeConstraint means "unspecified" (no type info declared). TypeAny means "explicitly accepts any value."

type UncaughtThreadException 

type UncaughtThreadException struct {
	Reason error
}

UncaughtThreadException wraps an exception that wasn't caught in a thread

func (*UncaughtThreadException) Error 

func (p *UncaughtThreadException) Error() string

func (*UncaughtThreadException) Unwrap 

func (p *UncaughtThreadException) Unwrap() error

type Value 

type Value interface {
	SchemeString() string
	IsVoid() bool
	EqualTo(Value) bool
}

Value is the base interface for all Scheme values.

Every runtime object in Wile implements Value. The three methods correspond to fundamental Scheme operations:

  • SchemeString returns the external representation (R7RS §6.13.3 write).
  • IsVoid reports whether this value represents the absence of a result (e.g., the return value of set! or display). A nil receiver must return true so that missing values are treated as void.
  • EqualTo implements structural equality (R7RS §6.1 equal?).

ADDING A NEW VALUE TYPE requires at minimum:

  1. values/<type>.go — implement Value (SchemeString, IsVoid, EqualTo)
  2. values/<type>_test.go — test the three Value methods + type-specific behavior

Depending on the type's role, also update:

  1. registry/core/prim_predicates.go — if it needs a type predicate (e.g., box?)
  2. ffi.go — if it maps to/from Go types via RegisterFunc
  3. values/scheme_writer.go — if it has internal structure that can be shared/circular
  4. machine/machine_context_apply.go — if it is callable (implements Callable)
  5. machine/native_template.go — if it can appear as a compile-time literal

For numeric types, see the more detailed guide in values/numeric_kind.go (12 items). 

var EOFObject Value = eofType{}

EOFObject is the singleton EOF value. 

var Void Value = voidType{}

Void is the singleton void value.

func ChannelSelect 

func ChannelSelect(cases []SelectCase) (idx int, val Value, ok bool)

ChannelSelect performs a select operation on multiple channels. Returns the index of the selected case and the received value (for receive cases). If a send case targets a channel that is closed concurrently, the select returns that case's index with ok=false instead of panicking.

func ForEach 

func ForEach(ctx context.Context, o Value, fn ForEachFunc) (Value, error)

ForEach iterates over a Tuple value, calling fn for each element. If the value is not a Tuple, returns the value unchanged with no error. The callback receives the element index, whether more elements follow, and the element value. Returns the tail of the tuple (EmptyList for proper lists) and any error from the callback.

func Single added in v1.5.0 

func Single(t Tuple) (Value, bool)

Single returns the sole element of a single-element Tuple, or false if the Tuple has zero or more than one element. This avoids ForEach and its closure allocation for the common case of 1-element rest-arg lists.

func StringOrFalse added in v1.10.7 

func StringOrFalse(s string) Value

StringOrFalse returns a Scheme string if s is non-empty, or #f if empty. Follows the BoolToBoolean precedent for eliminating repeated if/else patterns.

type ValueType added in v1.10.3 

type ValueType uint8

ValueType represents a Scheme type constraint for extension API contracts. Each constant maps to either a concrete Go type or an interface in the values package. 

const (
	TypeAny               ValueType = iota // any Value
	TypeVoid                               // void singleton
	TypeBoolean                            // *Boolean
	TypeNumber                             // Number interface
	TypeComplex                            // ComplexNumber interface
	TypeReal                               // RealNumber interface
	TypeRational                           // *Rational
	TypeInteger                            // *Integer | *BigInteger
	TypeExactInteger                       // alias for TypeInteger
	TypeFlonum                             // *Float | *BigFloat
	TypeString                             // *String
	TypeCharacter                          // *Character
	TypeSymbol                             // *Symbol
	TypeByte                               // *Byte
	TypePair                               // *Pair
	TypeList                               // Tuple interface
	TypeVector                             // *Vector
	TypeByteVector                         // *ByteVector
	TypeHashtable                          // *Hashtable
	TypeProcedure                          // Callable interface
	TypePort                               // Port interface
	TypeInputPort                          // InputPort interface
	TypeOutputPort                         // OutputPort interface
	TypeTextualInputPort                   // TextualReader interface
	TypeTextualOutputPort                  // TextualWriter interface
	TypeBinaryInputPort                    // BinaryReader interface
	TypeBinaryOutputPort                   // BinaryWriter interface
	TypeCount                              // sentinel — must be last
)

func (ValueType) Check added in v1.10.3 

func (p ValueType) Check(v Value) (any, bool, error)

Check tests whether v satisfies this type constraint. On success, returns the narrowed value and true. On failure, returns nil, false, and an error describing the mismatch.

func (ValueType) Description added in v1.10.3 

func (p ValueType) Description() string

Description returns a human-readable description of the type constraint.

func (ValueType) Name added in v1.12.0 

func (p ValueType) Name() string

Name returns the Scheme-facing type name, satisfying the TypeConstraint interface.

func (ValueType) String added in v1.10.3 

func (p ValueType) String() string

String returns the Scheme-style name for the type (e.g., "integer", "pair").

type Vector 

type Vector []Value

Vector represents an R7RS vector, a fixed-size mutable array of values. Vectors are written as #(element ...) in Scheme syntax. Unlike lists, vectors provide O(1) access to elements by index.

func NewVector 

func NewVector(vs ...Value) *Vector

NewVector creates a new Vector from the given values. Returns an empty vector if no arguments are provided.

func NewVectorWithLength 

func NewVectorWithLength(length int) *Vector

NewVectorWithLength creates a new Vector of the given length, with all elements initialized to the specified fill value.

func (*Vector) AsList 

func (p *Vector) AsList() Tuple

AsList converts the vector to a proper list (linked list of pairs). Returns void (nil Pair) if the vector is void. Returns EmptyList if the vector is empty. Otherwise returns a newly constructed list containing the vector's elements.

func (*Vector) Datum 

func (p *Vector) Datum() []Value

Datum returns the underlying slice of values. Returns nil if the vector is void (nil pointer).

func (*Vector) EqualTo 

func (p *Vector) EqualTo(v Value) bool

EqualTo implements structural equality for vectors. Two vectors are equal if they have the same length and all corresponding elements are equal (using recursive EqualTo comparison). Returns false if the other value is not a Vector.

func (*Vector) Get 

func (p *Vector) Get(i int) Value

Get returns the element at the specified index.

func (*Vector) IsVoid 

func (p *Vector) IsVoid() bool

IsVoid returns true if the vector is a nil pointer. A nil vector represents the absence of a value, distinct from an empty vector.

func (*Vector) Length 

func (p *Vector) Length() int

Length returns the number of elements in the vector. Returns 0 if the vector is void (nil pointer).

func (*Vector) SchemeString 

func (p *Vector) SchemeString() string

SchemeString returns the Scheme external representation of the vector. Format: #( element1 element2 ... ) with elements separated by spaces. Empty vectors are represented as #().

func (*Vector) Set 

func (p *Vector) Set(i int, value Value) error

Set sets the element at the specified index to the given value. Vectors are always mutable, so this never returns an error.

type WaitGroup 

type WaitGroup struct {
	// contains filtered or unexported fields
}

WaitGroup wraps sync.WaitGroup for Scheme

func NewWaitGroup 

func NewWaitGroup() *WaitGroup

NewWaitGroup creates a new WaitGroup

func (*WaitGroup) Add 

func (p *WaitGroup) Add(delta int)

Add adds delta to the counter

func (*WaitGroup) Done 

func (p *WaitGroup) Done()

Done decrements the counter by one

func (*WaitGroup) EqualTo 

func (p *WaitGroup) EqualTo(v Value) bool

EqualTo returns true if the wait groups are the same object.

func (*WaitGroup) ID 

func (p *WaitGroup) ID() uint64

ID returns the WaitGroup's unique identifier

func (*WaitGroup) IsVoid 

func (p *WaitGroup) IsVoid() bool

IsVoid returns true if the wait group is nil.

func (*WaitGroup) SchemeString 

func (p *WaitGroup) SchemeString() string

SchemeString returns the Scheme representation of the wait group.

func (*WaitGroup) Wait 

func (p *WaitGroup) Wait()

Wait blocks until the counter is zero

type WriteMode 

type WriteMode int

WriteMode controls how the SchemeWriter handles shared structure.

R7RS §6.13.3 specifies three output procedures with different sharing semantics:

  • write: datum labels only for circular references (WriteModeWrite)
  • write-shared: datum labels for all shared references (WriteModeWriteShared)
  • write-simple: no datum labels at all (handled separately via SchemeString)
const (
	// WriteModeWrite labels only circular references.
	// R7RS §6.13.3: write outputs datum labels only for objects that are part of a cycle.
	WriteModeWrite WriteMode = iota
	// WriteModeWriteShared labels all multiply-referenced objects.
	// R7RS §6.13.3: write-shared outputs datum labels for all shared structure.
	WriteModeWriteShared
)

Source Files

View all Source files

Directories

Path Synopsis
Package valuestest provides test helpers for the values package.
 Package valuestest provides test helpers for the values package.

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