Documentation
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Index ¶
- func CmpOpts() []cmp.Option
- func Contains[T comparable](option Option[T], matches T) bool
- func Equal[T comparable](a, b Option[T]) bool
- func Fold[T, R any](option Option[T], defaultValue R, f func(T) R) R
- func FoldLeft[T, R any](option Option[T], zero R, f func(accum R, value T) R) R
- func ToNullBool(o Option[bool]) sql.NullBool
- func ToNullString(o Option[string]) sql.NullString
- func ToNullTime(o Option[time.Time]) sql.NullTime
- type Option
- func AsOptional[T comparable](v T) Option[T]
- func CommaOk[T any](v T, ok bool) Option[T]
- func FlatMap[T, R any](option Option[T], f func(T) Option[R]) Option[R]
- func FromErr(err error) Option[string]
- func FromPointer[T any](v *T) Option[T]
- func Map[T, R any](option Option[T], f func(T) R) Option[R]
- func None[T any]() Option[T]
- func Some[T any](v T) Option[T]
- func (o Option[T]) Contains(predicate func(v T) bool) bool
- func (o Option[T]) Empty() bool
- func (o Option[T]) ForAll(f func(v T))
- func (o Option[T]) ForEach(predicate func(v T) bool) bool
- func (o Option[T]) Get() (val T, ok bool)
- func (o Option[T]) GetOrElse(alternative T) T
- func (o Option[T]) GetOrElseF(alternative func() T) T
- func (o Option[T]) MarshalJSON() ([]byte, error)
- func (o Option[T]) MustGet() (rtn T)
- func (o Option[T]) OrElse(alternative T) Option[T]
- func (o Option[T]) Present() bool
- func (o Option[T]) PtrOrNil() *T
- func (o Option[T]) String() string
- func (o *Option[T]) UnmarshalJSON(data []byte) error
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func CmpOpts ¶ added in v1.33.0
CmpOpts returns the options to use to compare options by checking the unexported fields. For testing purposes.
func Contains ¶
func Contains[T comparable](option Option[T], matches T) bool
Contains returns true if the option is present and matches the given value
func Equal ¶ added in v1.52.4
func Equal[T comparable](a, b Option[T]) bool
Equal returns true if both Options are equal.
func Fold ¶
Fold returns the result of f applied to the value if present, otherwise returns the defaultValue
func FoldLeft ¶
FoldLeft applies the binary operator f to the value if present, otherwise returns the zero value
func ToNullString ¶ added in v1.52.3
func ToNullString(o Option[string]) sql.NullString
Types ¶
type Option ¶
type Option[T any] struct { // contains filtered or unexported fields }
Option is a type that represents a value that may or may not be present
It is different a normal value as it can distinguish between a zero value and a missing value even on pointer types
func AsOptional ¶
func AsOptional[T comparable](v T) Option[T]
AsOptional returns an Option where a zero value T is considered None and any other value is considered Some
i.e.
AsOptional(nil) == None()
AsOptional(0) == None()
AsOptional(false) == None()
AsOptional("") == None()
AsOptional(&MyStruct{}) == Some(&MyStruct{})
AsOptional(1) == Some(1)
AsOptional(true) == Some(true)
func CommaOk ¶
CommaOk is a helper function to convert a comma ok idiom into an Option. If ok is true it returns Some(v), otherwise it returns None.
func FlatMap ¶
FlatMap returns an Option with the value mapped by the given function if present, otherwise returns None
func FromErr ¶ added in v1.52.4
FromErr returns an Option[string] where a nil error is considered None and any other value is considered Some, with the error message as the value.
func FromPointer ¶ added in v1.21.1
FromPointer returns an Option where a nil pointer is considered None and any other value is considered Some, with the value dereferenced.
func Map ¶
Map returns an Option with the value mapped by the given function if present, otherwise returns None
func Some ¶
Some returns an Option with the given value and present set to true
This means Some(nil) is a valid present Option and Some(nil) != None()
func (Option[T]) Contains ¶
Contains returns true if the Option is present and the given predicate returns true on the value otherwise returns false
func (Option[T]) ForAll ¶
func (o Option[T]) ForAll(f func(v T))
ForAll calls the given function with the value if present
func (Option[T]) ForEach ¶
ForEach returns true if the Option is empty or the given predicate returns true on the value
func (Option[T]) GetOrElse ¶
func (o Option[T]) GetOrElse(alternative T) T
GetOrElse returns the value if present, otherwise returns the alternative value
func (Option[T]) GetOrElseF ¶
func (o Option[T]) GetOrElseF(alternative func() T) T
GetOrElseF returns the value if present, otherwise returns the alternative value
func (Option[T]) MarshalJSON ¶ added in v1.33.0
func (Option[T]) MustGet ¶
func (o Option[T]) MustGet() (rtn T)
MustGet returns the value if present, otherwise panics
func (Option[T]) OrElse ¶
OrElse returns an Option with the value if present, otherwise returns the alternative value
func (Option[T]) PtrOrNil ¶ added in v1.19.0
func (o Option[T]) PtrOrNil() *T
PtrOrNil returns the value as a pointer, if present, or nil otherwise.
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