decimal: github.com/shopspring/decimal Index | Examples | Files

package decimal

import "github.com/shopspring/decimal"

Multiprecision decimal numbers. For floating-point formatting only; not general purpose. Only operations are assign and (binary) left/right shift. Can do binary floating point in multiprecision decimal precisely because 2 divides 10; cannot do decimal floating point in multiprecision binary precisely.

Package decimal implements an arbitrary precision fixed-point decimal.

To use as part of a struct:

type Struct struct {
    Number Decimal
}

The zero-value of a Decimal is 0, as you would expect.

The best way to create a new Decimal is to use decimal.NewFromString, ex:

n, err := decimal.NewFromString("-123.4567")
n.String() // output: "-123.4567"

NOTE: This can "only" represent numbers with a maximum of 2^31 digits after the decimal point.

Multiprecision decimal numbers. For floating-point formatting only; not general purpose. Only operations are assign and (binary) left/right shift. Can do binary floating point in multiprecision decimal precisely because 2 divides 10; cannot do decimal floating point in multiprecision binary precisely.

Index

Examples

Package Files

decimal-go.go decimal.go decomposer.go rounding.go

Variables

var DivisionPrecision = 16

DivisionPrecision is the number of decimal places in the result when it doesn't divide exactly.

Example:

d1 := decimal.NewFromFloat(2).Div(decimal.NewFromFloat(3)
d1.String() // output: "0.6666666666666667"
d2 := decimal.NewFromFloat(2).Div(decimal.NewFromFloat(30000)
d2.String() // output: "0.0000666666666667"
d3 := decimal.NewFromFloat(20000).Div(decimal.NewFromFloat(3)
d3.String() // output: "6666.6666666666666667"
decimal.DivisionPrecision = 3
d4 := decimal.NewFromFloat(2).Div(decimal.NewFromFloat(3)
d4.String() // output: "0.667"
var MarshalJSONWithoutQuotes = false

MarshalJSONWithoutQuotes should be set to true if you want the decimal to be JSON marshaled as a number, instead of as a string. WARNING: this is dangerous for decimals with many digits, since many JSON unmarshallers (ex: Javascript's) will unmarshal JSON numbers to IEEE 754 double-precision floating point numbers, which means you can potentially silently lose precision.

var Zero = New(0, 1)

Zero constant, to make computations faster.

type Decimal Uses

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

Decimal represents a fixed-point decimal. It is immutable. number = value * 10 ^ exp

func Avg Uses

func Avg(first Decimal, rest ...Decimal) Decimal

Avg returns the average value of the provided first and rest Decimals

func Max Uses

func Max(first Decimal, rest ...Decimal) Decimal

Max returns the largest Decimal that was passed in the arguments.

To call this function with an array, you must do:

Max(arr[0], arr[1:]...)

This makes it harder to accidentally call Max with 0 arguments.

func Min Uses

func Min(first Decimal, rest ...Decimal) Decimal

Min returns the smallest Decimal that was passed in the arguments.

To call this function with an array, you must do:

Min(arr[0], arr[1:]...)

This makes it harder to accidentally call Min with 0 arguments.

func New Uses

func New(value int64, exp int32) Decimal

New returns a new fixed-point decimal, value * 10 ^ exp.

func NewFromBigInt Uses

func NewFromBigInt(value *big.Int, exp int32) Decimal

NewFromBigInt returns a new Decimal from a big.Int, value * 10 ^ exp

func NewFromFloat Uses

func NewFromFloat(value float64) Decimal

NewFromFloat converts a float64 to Decimal.

The converted number will contain the number of significant digits that can be represented in a float with reliable roundtrip. This is typically 15 digits, but may be more in some cases. See https://www.exploringbinary.com/decimal-precision-of-binary-floating-point-numbers/ for more information.

For slightly faster conversion, use NewFromFloatWithExponent where you can specify the precision in absolute terms.

NOTE: this will panic on NaN, +/-inf

Code:

fmt.Println(NewFromFloat(123.123123123123).String())
fmt.Println(NewFromFloat(.123123123123123).String())
fmt.Println(NewFromFloat(-1e13).String())

Output:

123.123123123123
0.123123123123123
-10000000000000

func NewFromFloat32 Uses

func NewFromFloat32(value float32) Decimal

NewFromFloat converts a float32 to Decimal.

The converted number will contain the number of significant digits that can be represented in a float with reliable roundtrip. This is typically 6-8 digits depending on the input. See https://www.exploringbinary.com/decimal-precision-of-binary-floating-point-numbers/ for more information.

For slightly faster conversion, use NewFromFloatWithExponent where you can specify the precision in absolute terms.

NOTE: this will panic on NaN, +/-inf

Code:

fmt.Println(NewFromFloat32(123.123123123123).String())
fmt.Println(NewFromFloat32(.123123123123123).String())
fmt.Println(NewFromFloat32(-1e13).String())

Output:

123.12312
0.123123124
-10000000000000

func NewFromFloatWithExponent Uses

func NewFromFloatWithExponent(value float64, exp int32) Decimal

NewFromFloatWithExponent converts a float64 to Decimal, with an arbitrary number of fractional digits.

Example:

NewFromFloatWithExponent(123.456, -2).String() // output: "123.46"

func NewFromString Uses

func NewFromString(value string) (Decimal, error)

NewFromString returns a new Decimal from a string representation.

Example:

d, err := NewFromString("-123.45")
d2, err := NewFromString(".0001")

func RequireFromString Uses

func RequireFromString(value string) Decimal

RequireFromString returns a new Decimal from a string representation or panics if NewFromString would have returned an error.

Example:

d := RequireFromString("-123.45")
d2 := RequireFromString(".0001")

func Sum Uses

func Sum(first Decimal, rest ...Decimal) Decimal

Sum returns the combined total of the provided first and rest Decimals

func (Decimal) Abs Uses

func (d Decimal) Abs() Decimal

Abs returns the absolute value of the decimal.

func (Decimal) Add Uses

func (d Decimal) Add(d2 Decimal) Decimal

Add returns d + d2.

func (Decimal) Atan Uses

func (x Decimal) Atan() Decimal

Atan returns the arctangent, in radians, of x.

func (Decimal) Ceil Uses

func (d Decimal) Ceil() Decimal

Ceil returns the nearest integer value greater than or equal to d.

func (Decimal) Cmp Uses

func (d Decimal) Cmp(d2 Decimal) int

Cmp compares the numbers represented by d and d2 and returns:

-1 if d <  d2
 0 if d == d2
+1 if d >  d2

func (Decimal) Coefficient Uses

func (d Decimal) Coefficient() *big.Int

Coefficient returns the coefficient of the decimal. It is scaled by 10^Exponent()

func (*Decimal) Compose Uses

func (d *Decimal) Compose(form byte, negative bool, coefficient []byte, exponent int32) error

Compose sets the internal decimal value from parts. If the value cannot be represented then an error should be returned.

func (Decimal) Cos Uses

func (d Decimal) Cos() Decimal

Cos returns the cosine of the radian argument x.

func (Decimal) Decompose Uses

func (d Decimal) Decompose(buf []byte) (form byte, negative bool, coefficient []byte, exponent int32)

Decompose returns the internal decimal state into parts. If the provided buf has sufficient capacity, buf may be returned as the coefficient with the value set and length set as appropriate.

func (Decimal) Div Uses

func (d Decimal) Div(d2 Decimal) Decimal

Div returns d / d2. If it doesn't divide exactly, the result will have DivisionPrecision digits after the decimal point.

func (Decimal) DivRound Uses

func (d Decimal) DivRound(d2 Decimal, precision int32) Decimal

DivRound divides and rounds to a given precision i.e. to an integer multiple of 10^(-precision)

for a positive quotient digit 5 is rounded up, away from 0
if the quotient is negative then digit 5 is rounded down, away from 0

Note that precision<0 is allowed as input.

func (Decimal) Equal Uses

func (d Decimal) Equal(d2 Decimal) bool

Equal returns whether the numbers represented by d and d2 are equal.

func (Decimal) Equals Uses

func (d Decimal) Equals(d2 Decimal) bool

Equals is deprecated, please use Equal method instead

func (Decimal) Exponent Uses

func (d Decimal) Exponent() int32

Exponent returns the exponent, or scale component of the decimal.

func (Decimal) Float64 Uses

func (d Decimal) Float64() (f float64, exact bool)

Float64 returns the nearest float64 value for d and a bool indicating whether f represents d exactly. For more details, see the documentation for big.Rat.Float64

func (Decimal) Floor Uses

func (d Decimal) Floor() Decimal

Floor returns the nearest integer value less than or equal to d.

func (*Decimal) GobDecode Uses

func (d *Decimal) GobDecode(data []byte) error

GobDecode implements the gob.GobDecoder interface for gob serialization.

func (Decimal) GobEncode Uses

func (d Decimal) GobEncode() ([]byte, error)

GobEncode implements the gob.GobEncoder interface for gob serialization.

func (Decimal) GreaterThan Uses

func (d Decimal) GreaterThan(d2 Decimal) bool

GreaterThan (GT) returns true when d is greater than d2.

func (Decimal) GreaterThanOrEqual Uses

func (d Decimal) GreaterThanOrEqual(d2 Decimal) bool

GreaterThanOrEqual (GTE) returns true when d is greater than or equal to d2.

func (Decimal) IntPart Uses

func (d Decimal) IntPart() int64

IntPart returns the integer component of the decimal.

func (Decimal) IsNegative Uses

func (d Decimal) IsNegative() bool

IsNegative return

true if d < 0
false if d == 0
false if d > 0

func (Decimal) IsPositive Uses

func (d Decimal) IsPositive() bool

IsPositive return

true if d > 0
false if d == 0
false if d < 0

func (Decimal) IsZero Uses

func (d Decimal) IsZero() bool

IsZero return

true if d == 0
false if d > 0
false if d < 0

func (Decimal) LessThan Uses

func (d Decimal) LessThan(d2 Decimal) bool

LessThan (LT) returns true when d is less than d2.

func (Decimal) LessThanOrEqual Uses

func (d Decimal) LessThanOrEqual(d2 Decimal) bool

LessThanOrEqual (LTE) returns true when d is less than or equal to d2.

func (Decimal) MarshalBinary Uses

func (d Decimal) MarshalBinary() (data []byte, err error)

MarshalBinary implements the encoding.BinaryMarshaler interface.

func (Decimal) MarshalJSON Uses

func (d Decimal) MarshalJSON() ([]byte, error)

MarshalJSON implements the json.Marshaler interface.

func (Decimal) MarshalText Uses

func (d Decimal) MarshalText() (text []byte, err error)

MarshalText implements the encoding.TextMarshaler interface for XML serialization.

func (Decimal) Mod Uses

func (d Decimal) Mod(d2 Decimal) Decimal

Mod returns d % d2.

func (Decimal) Mul Uses

func (d Decimal) Mul(d2 Decimal) Decimal

Mul returns d * d2.

func (Decimal) Neg Uses

func (d Decimal) Neg() Decimal

Neg returns -d.

func (Decimal) Pow Uses

func (d Decimal) Pow(d2 Decimal) Decimal

Pow returns d to the power d2

func (Decimal) QuoRem Uses

func (d Decimal) QuoRem(d2 Decimal, precision int32) (Decimal, Decimal)

QuoRem does divsion with remainder d.QuoRem(d2,precision) returns quotient q and remainder r such that

d = d2 * q + r, q an integer multiple of 10^(-precision)
0 <= r < abs(d2) * 10 ^(-precision) if d>=0
0 >= r > -abs(d2) * 10 ^(-precision) if d<0

Note that precision<0 is allowed as input.

func (Decimal) Rat Uses

func (d Decimal) Rat() *big.Rat

Rat returns a rational number representation of the decimal.

func (Decimal) Round Uses

func (d Decimal) Round(places int32) Decimal

Round rounds the decimal to places decimal places. If places < 0, it will round the integer part to the nearest 10^(-places).

Example:

NewFromFloat(5.45).Round(1).String() // output: "5.5"
NewFromFloat(545).Round(-1).String() // output: "550"

func (Decimal) RoundBank Uses

func (d Decimal) RoundBank(places int32) Decimal

RoundBank rounds the decimal to places decimal places. If the final digit to round is equidistant from the nearest two integers the rounded value is taken as the even number

If places < 0, it will round the integer part to the nearest 10^(-places).

Examples:

NewFromFloat(5.45).Round(1).String() // output: "5.4"
NewFromFloat(545).Round(-1).String() // output: "540"
NewFromFloat(5.46).Round(1).String() // output: "5.5"
NewFromFloat(546).Round(-1).String() // output: "550"
NewFromFloat(5.55).Round(1).String() // output: "5.6"
NewFromFloat(555).Round(-1).String() // output: "560"

func (Decimal) RoundCash Uses

func (d Decimal) RoundCash(interval uint8) Decimal

RoundCash aka Cash/Penny/öre rounding rounds decimal to a specific interval. The amount payable for a cash transaction is rounded to the nearest multiple of the minimum currency unit available. The following intervals are available: 5, 10, 15, 25, 50 and 100; any other number throws a panic.

  5:   5 cent rounding 3.43 => 3.45
 10:  10 cent rounding 3.45 => 3.50 (5 gets rounded up)
 15:  10 cent rounding 3.45 => 3.40 (5 gets rounded down)
 25:  25 cent rounding 3.41 => 3.50
 50:  50 cent rounding 3.75 => 4.00
100: 100 cent rounding 3.50 => 4.00

For more details: https://en.wikipedia.org/wiki/Cash_rounding

func (*Decimal) Scan Uses

func (d *Decimal) Scan(value interface{}) error

Scan implements the sql.Scanner interface for database deserialization.

func (Decimal) Shift Uses

func (d Decimal) Shift(shift int32) Decimal

Shift shifts the decimal in base 10. It shifts left when shift is positive and right if shift is negative. In simpler terms, the given value for shift is added to the exponent of the decimal.

func (Decimal) Sign Uses

func (d Decimal) Sign() int

Sign returns:

-1 if d <  0
 0 if d == 0
+1 if d >  0

func (Decimal) Sin Uses

func (d Decimal) Sin() Decimal

Sin returns the sine of the radian argument x.

func (Decimal) String Uses

func (d Decimal) String() string

String returns the string representation of the decimal with the fixed point.

Example:

d := New(-12345, -3)
println(d.String())

Output:

-12.345

func (Decimal) StringFixed Uses

func (d Decimal) StringFixed(places int32) string

StringFixed returns a rounded fixed-point string with places digits after the decimal point.

Example:

NewFromFloat(0).StringFixed(2) // output: "0.00"
NewFromFloat(0).StringFixed(0) // output: "0"
NewFromFloat(5.45).StringFixed(0) // output: "5"
NewFromFloat(5.45).StringFixed(1) // output: "5.5"
NewFromFloat(5.45).StringFixed(2) // output: "5.45"
NewFromFloat(5.45).StringFixed(3) // output: "5.450"
NewFromFloat(545).StringFixed(-1) // output: "550"

func (Decimal) StringFixedBank Uses

func (d Decimal) StringFixedBank(places int32) string

StringFixedBank returns a banker rounded fixed-point string with places digits after the decimal point.

Example:

NewFromFloat(0).StringFixed(2) // output: "0.00"
NewFromFloat(0).StringFixed(0) // output: "0"
NewFromFloat(5.45).StringFixed(0) // output: "5"
NewFromFloat(5.45).StringFixed(1) // output: "5.4"
NewFromFloat(5.45).StringFixed(2) // output: "5.45"
NewFromFloat(5.45).StringFixed(3) // output: "5.450"
NewFromFloat(545).StringFixed(-1) // output: "550"

func (Decimal) StringFixedCash Uses

func (d Decimal) StringFixedCash(interval uint8) string

StringFixedCash returns a Swedish/Cash rounded fixed-point string. For more details see the documentation at function RoundCash.

func (Decimal) StringScaled Uses

func (d Decimal) StringScaled(exp int32) string

StringScaled first scales the decimal then calls .String() on it. NOTE: buggy, unintuitive, and DEPRECATED! Use StringFixed instead.

func (Decimal) Sub Uses

func (d Decimal) Sub(d2 Decimal) Decimal

Sub returns d - d2.

func (Decimal) Tan Uses

func (d Decimal) Tan() Decimal

Tan returns the tangent of the radian argument x.

func (Decimal) Truncate Uses

func (d Decimal) Truncate(precision int32) Decimal

Truncate truncates off digits from the number, without rounding.

NOTE: precision is the last digit that will not be truncated (must be >= 0).

Example:

decimal.NewFromString("123.456").Truncate(2).String() // "123.45"

func (*Decimal) UnmarshalBinary Uses

func (d *Decimal) UnmarshalBinary(data []byte) error

UnmarshalBinary implements the encoding.BinaryUnmarshaler interface. As a string representation is already used when encoding to text, this method stores that string as []byte

func (*Decimal) UnmarshalJSON Uses

func (d *Decimal) UnmarshalJSON(decimalBytes []byte) error

UnmarshalJSON implements the json.Unmarshaler interface.

func (*Decimal) UnmarshalText Uses

func (d *Decimal) UnmarshalText(text []byte) error

UnmarshalText implements the encoding.TextUnmarshaler interface for XML deserialization.

func (Decimal) Value Uses

func (d Decimal) Value() (driver.Value, error)

Value implements the driver.Valuer interface for database serialization.

type NullDecimal Uses

type NullDecimal struct {
    Decimal Decimal
    Valid   bool
}

NullDecimal represents a nullable decimal with compatibility for scanning null values from the database.

func (NullDecimal) MarshalJSON Uses

func (d NullDecimal) MarshalJSON() ([]byte, error)

MarshalJSON implements the json.Marshaler interface.

func (*NullDecimal) Scan Uses

func (d *NullDecimal) Scan(value interface{}) error

Scan implements the sql.Scanner interface for database deserialization.

func (*NullDecimal) UnmarshalJSON Uses

func (d *NullDecimal) UnmarshalJSON(decimalBytes []byte) error

UnmarshalJSON implements the json.Unmarshaler interface.

func (NullDecimal) Value Uses

func (d NullDecimal) Value() (driver.Value, error)

Value implements the driver.Valuer interface for database serialization.

Package decimal imports 7 packages (graph) and is imported by 1181 packages. Updated 2019-10-09. Refresh now. Tools for package owners.