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Overview ¶
Package decimal with support of Tarantool's decimal data type.
Decimal data type supported in Tarantool since 2.2.
Since: 1.7.0
See also:
Tarantool MessagePack extensions: https://www.tarantool.io/en/doc/latest/dev_guide/internals/msgpack_extensions/#the-decimal-type
Tarantool data model: https://www.tarantool.io/en/doc/latest/book/box/data_model/
Tarantool issue for support decimal type: https://github.com/tarantool/tarantool/issues/692
Tarantool module decimal: https://www.tarantool.io/en/doc/latest/reference/reference_lua/decimal/
Example ¶
To enable support of decimal in msgpack with https://github.com/shopspring/decimal, import tarantool/decimal submodule.
server := "127.0.0.1:3013"
dialer := tarantool.NetDialer{
Address: server,
User: "test",
Password: "test",
}
opts := tarantool.Opts{
Timeout: 5 * time.Second,
}
ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
client, err := tarantool.Connect(ctx, dialer, opts)
cancel()
if err != nil {
log.Fatalf("Failed to connect: %s", err.Error())
}
spaceNo := uint32(524)
number, err := MakeDecimalFromString("-22.804")
if err != nil {
log.Fatalf("Failed to prepare test decimal: %s", err)
}
data, err := client.Do(tarantool.NewReplaceRequest(spaceNo).
Tuple([]interface{}{number}),
).Get()
if err != nil {
log.Fatalf("Decimal replace failed: %s", err)
}
log.Println("Decimal tuple replace")
log.Println("Error", err)
log.Println("Data", data)
Index ¶
- Variables
- type Decimal
- type OptionalDecimal
- func (o *OptionalDecimal) DecodeMsgpack(decoder *msgpack.Decoder) error
- func (o OptionalDecimal) EncodeMsgpack(encoder *msgpack.Encoder) error
- func (o OptionalDecimal) Get() (Decimal, bool)
- func (o OptionalDecimal) IsNil() bool
- func (o OptionalDecimal) IsSome() bool
- func (o OptionalDecimal) IsZero() bool
- func (o OptionalDecimal) MustGet() Decimal
- func (o OptionalDecimal) Unwrap() Decimal
- func (o OptionalDecimal) UnwrapOr(defaultValue Decimal) Decimal
- func (o OptionalDecimal) UnwrapOrElse(defaultValue func() Decimal) Decimal
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var ( ErrDecimalOverflow = fmt.Errorf("msgpack: decimal number is bigger than"+ " maximum supported number (10^%d - 1)", decimalPrecision) ErrDecimalUnderflow = fmt.Errorf("msgpack: decimal number is lesser than"+ " minimum supported number (-10^%d - 1)", decimalPrecision) )
Functions ¶
This section is empty.
Types ¶
type Decimal ¶
func MakeDecimal ¶
MakeDecimal creates a new Decimal from a decimal.Decimal.
func MakeDecimalFromString ¶
MakeDecimalFromString creates a new Decimal from a string.
func (Decimal) MarshalMsgpack ¶
MarshalMsgpack implements a custom msgpack marshaler.
func (*Decimal) UnmarshalMsgpack ¶
UnmarshalMsgpack implements a custom msgpack unmarshaler.
type OptionalDecimal ¶
type OptionalDecimal struct {
// contains filtered or unexported fields
}
OptionalDecimal represents an optional value of type Decimal. It can either hold a valid Decimal (IsSome == true) or be empty (IsZero == true).
func NoneOptionalDecimal ¶
func NoneOptionalDecimal() OptionalDecimal
NoneOptionalDecimal creates an empty optional OptionalDecimal value. The returned OptionalDecimal will have IsSome() == false and IsZero() == true.
Example:
o := NoneOptionalDecimal()
if o.IsZero() {
fmt.Println("value is absent")
}
func SomeOptionalDecimal ¶
func SomeOptionalDecimal(value Decimal) OptionalDecimal
SomeOptionalDecimal creates an optional OptionalDecimal with the given Decimal value. The returned OptionalDecimal will have IsSome() == true and IsZero() == false.
func (*OptionalDecimal) DecodeMsgpack ¶
func (o *OptionalDecimal) DecodeMsgpack(decoder *msgpack.Decoder) error
DecodeMsgpack decodes a OptionalDecimal value from MessagePack format. Supports two input types:
- nil: interpreted as no value (NoneOptionalDecimal)
- Decimal: interpreted as a present value (SomeOptionalDecimal)
Returns an error if the input type is unsupported or decoding fails.
After successful decoding:
- on nil: exists = false, value = default zero value
- on Decimal: exists = true, value = decoded value
func (OptionalDecimal) EncodeMsgpack ¶
func (o OptionalDecimal) EncodeMsgpack(encoder *msgpack.Encoder) error
EncodeMsgpack encodes the OptionalDecimal value using MessagePack format. - If the value is present, it is encoded as Decimal. - If the value is absent (None), it is encoded as nil.
Returns an error if encoding fails.
func (OptionalDecimal) Get ¶
func (o OptionalDecimal) Get() (Decimal, bool)
Get returns the stored value and a boolean flag indicating its presence. If the value is present, returns (value, true). If the value is absent, returns (zero value of Decimal, false).
Recommended usage:
if value, ok := o.Get(); ok {
// use value
}
func (OptionalDecimal) IsNil ¶
func (o OptionalDecimal) IsNil() bool
IsNil is an alias for IsZero.
This method is provided for compatibility with the msgpack Encoder interface.
func (OptionalDecimal) IsSome ¶
func (o OptionalDecimal) IsSome() bool
IsSome returns true if the OptionalDecimal contains a value. This indicates the value is explicitly set (not None).
func (OptionalDecimal) IsZero ¶
func (o OptionalDecimal) IsZero() bool
IsZero returns true if the OptionalDecimal does not contain a value. Equivalent to !IsSome(). Useful for consistency with types where zero value (e.g. 0, false, zero struct) is valid and needs to be distinguished.
func (OptionalDecimal) MustGet ¶
func (o OptionalDecimal) MustGet() Decimal
MustGet returns the stored value if it is present. Panics if the value is absent (i.e., IsZero() == true).
Use with caution — only when you are certain the value exists.
Panics with: "optional value is not set" if no value is set.
func (OptionalDecimal) Unwrap ¶
func (o OptionalDecimal) Unwrap() Decimal
Unwrap returns the stored value regardless of presence. If no value is set, returns the zero value for Decimal.
Warning: Does not check presence. Use IsSome() before calling if you need to distinguish between absent value and explicit zero value.
func (OptionalDecimal) UnwrapOr ¶
func (o OptionalDecimal) UnwrapOr(defaultValue Decimal) Decimal
UnwrapOr returns the stored value if present. Otherwise, returns the provided default value.
Example:
o := NoneOptionalDecimal() v := o.UnwrapOr(someDefaultOptionalDecimal)
func (OptionalDecimal) UnwrapOrElse ¶
func (o OptionalDecimal) UnwrapOrElse(defaultValue func() Decimal) Decimal
UnwrapOrElse returns the stored value if present. Otherwise, calls the provided function and returns its result. Useful when the default value requires computation or side effects.
Example:
o := NoneOptionalDecimal()
v := o.UnwrapOrElse(func() Decimal { return computeDefault() })
Source Files