mirror of
https://github.com/shopspring/decimal.git
synced 2024-11-25 13:50:49 +01:00
Compare commits
15 commits
2c089d57b4
...
e117758075
Author | SHA1 | Date | |
---|---|---|---|
|
e117758075 | ||
|
d00399e161 | ||
|
57a340d853 | ||
|
b79c571f80 | ||
|
b844c58a71 | ||
|
142a0cf2f2 | ||
|
7b4ffbcd3c | ||
|
1df8fb3015 | ||
|
572d78e32d | ||
|
b4c250139b | ||
|
304c9d6794 | ||
|
12e9241da2 | ||
|
88705b71ce | ||
|
6926256b71 | ||
|
e5ee5e5502 |
7 changed files with 561 additions and 147 deletions
8
.github/workflows/ci.yml
vendored
8
.github/workflows/ci.yml
vendored
|
@ -1,16 +1,16 @@
|
|||
name: decimal-ci
|
||||
name: ci
|
||||
on: [push]
|
||||
jobs:
|
||||
ci-job:
|
||||
runs-on: ubuntu-latest
|
||||
strategy:
|
||||
matrix:
|
||||
go: [ '1.7.x', '1.15', '1.16', '1.17', '1.x' ]
|
||||
go: [ '1.7.x', '1.18', '1.19', '1.20', '1.21', '1.x' ]
|
||||
name: Go ${{ matrix.go }}
|
||||
steps:
|
||||
- uses: actions/checkout@v2
|
||||
- uses: actions/checkout@v4
|
||||
- name: Use go
|
||||
uses: actions/setup-go@v2
|
||||
uses: actions/setup-go@v5
|
||||
with:
|
||||
go-version: ${{ matrix.go }}
|
||||
- run: go build .
|
||||
|
|
|
@ -1,6 +1,6 @@
|
|||
# decimal
|
||||
|
||||
[![Github Actions](https://github.com/shopspring/decimal/actions/workflows/ci.yml/badge.svg)](https://github.com/shopspring/decimal/actions/workflows/ci.yml)
|
||||
[![ci](https://github.com/shopspring/decimal/actions/workflows/ci.yml/badge.svg?branch=master)](https://github.com/shopspring/decimal/actions/workflows/ci.yml)
|
||||
[![GoDoc](https://godoc.org/github.com/shopspring/decimal?status.svg)](https://godoc.org/github.com/shopspring/decimal)
|
||||
[![Go Report Card](https://goreportcard.com/badge/github.com/shopspring/decimal)](https://goreportcard.com/report/github.com/shopspring/decimal)
|
||||
|
||||
|
|
63
const.go
Normal file
63
const.go
Normal file
|
@ -0,0 +1,63 @@
|
|||
package decimal
|
||||
|
||||
import (
|
||||
"strings"
|
||||
)
|
||||
|
||||
const (
|
||||
strLn10 = "2.302585092994045684017991454684364207601101488628772976033327900967572609677352480235997205089598298341967784042286248633409525465082806756666287369098781689482907208325554680843799894826233198528393505308965377732628846163366222287698219886746543667474404243274365155048934314939391479619404400222105101714174800368808401264708068556774321622835522011480466371565912137345074785694768346361679210180644507064800027750268491674655058685693567342067058113642922455440575892572420824131469568901675894025677631135691929203337658714166023010570308963457207544037084746994016826928280848118428931484852494864487192780967627127577539702766860595249671667418348570442250719796500471495105049221477656763693866297697952211071826454973477266242570942932258279850258550978526538320760672631716430950599508780752371033310119785754733154142180842754386359177811705430982748238504564801909561029929182431823752535770975053956518769751037497088869218020518933950723853920514463419726528728696511086257149219884997874887377134568620916705849807828059751193854445009978131146915934666241071846692310107598438319191292230792503747298650929009880391941702654416816335727555703151596113564846546190897042819763365836983716328982174407366009162177850541779276367731145041782137660111010731042397832521894898817597921798666394319523936855916447118246753245630912528778330963604262982153040874560927760726641354787576616262926568298704957954913954918049209069438580790032763017941503117866862092408537949861264933479354871737451675809537088281067452440105892444976479686075120275724181874989395971643105518848195288330746699317814634930000321200327765654130472621883970596794457943468343218395304414844803701305753674262153675579814770458031413637793236291560128185336498466942261465206459942072917119370602444929358037007718981097362533224548366988505528285966192805098447175198503666680874970496982273220244823343097169111136813588418696549323714996941979687803008850408979618598756579894836445212043698216415292987811742973332588607915912510967187510929248475023930572665446276200923068791518135803477701295593646298412366497023355174586195564772461857717369368404676577047874319780573853271810933883496338813069945569399346101090745616033312247949360455361849123333063704751724871276379140924398331810164737823379692265637682071706935846394531616949411701841938119405416449466111274712819705817783293841742231409930022911502362192186723337268385688273533371925103412930705632544426611429765388301822384091026198582888433587455960453004548370789052578473166283701953392231047527564998119228742789713715713228319641003422124210082180679525276689858180956119208391760721080919923461516952599099473782780648128058792731993893453415320185969711021407542282796298237068941764740642225757212455392526179373652434440560595336591539160312524480149313234572453879524389036839236450507881731359711238145323701508413491122324390927681724749607955799151363982881058285740538000653371655553014196332241918087621018204919492651483892"
|
||||
)
|
||||
|
||||
var (
|
||||
ln10 = newConstApproximation(strLn10)
|
||||
)
|
||||
|
||||
type constApproximation struct {
|
||||
exact Decimal
|
||||
approximations []Decimal
|
||||
}
|
||||
|
||||
func newConstApproximation(value string) constApproximation {
|
||||
parts := strings.Split(value, ".")
|
||||
coeff, fractional := parts[0], parts[1]
|
||||
|
||||
coeffLen := len(coeff)
|
||||
maxPrecision := len(fractional)
|
||||
|
||||
var approximations []Decimal
|
||||
for p := 1; p < maxPrecision; p *= 2 {
|
||||
r := RequireFromString(value[:coeffLen+p])
|
||||
approximations = append(approximations, r)
|
||||
}
|
||||
|
||||
return constApproximation{
|
||||
RequireFromString(value),
|
||||
approximations,
|
||||
}
|
||||
}
|
||||
|
||||
// Returns the smallest approximation available that's at least as precise
|
||||
// as the passed precision (places after decimal point), i.e. Floor[ log2(precision) ] + 1
|
||||
func (c constApproximation) withPrecision(precision int32) Decimal {
|
||||
i := 0
|
||||
|
||||
if precision >= 1 {
|
||||
i++
|
||||
}
|
||||
|
||||
for precision >= 16 {
|
||||
precision /= 16
|
||||
i += 4
|
||||
}
|
||||
|
||||
for precision >= 2 {
|
||||
precision /= 2
|
||||
i++
|
||||
}
|
||||
|
||||
if i >= len(c.approximations) {
|
||||
return c.exact
|
||||
}
|
||||
|
||||
return c.approximations[i]
|
||||
}
|
34
const_test.go
Normal file
34
const_test.go
Normal file
|
@ -0,0 +1,34 @@
|
|||
package decimal
|
||||
|
||||
import "testing"
|
||||
|
||||
func TestConstApproximation(t *testing.T) {
|
||||
for _, testCase := range []struct {
|
||||
Const string
|
||||
Precision int32
|
||||
ExpectedApproximation string
|
||||
}{
|
||||
{"2.3025850929940456840179914546", 0, "2"},
|
||||
{"2.3025850929940456840179914546", 1, "2.3"},
|
||||
{"2.3025850929940456840179914546", 3, "2.302"},
|
||||
{"2.3025850929940456840179914546", 5, "2.302585"},
|
||||
{"2.3025850929940456840179914546", 10, "2.302585092994045"},
|
||||
{"2.3025850929940456840179914546", 100, "2.3025850929940456840179914546"},
|
||||
{"2.3025850929940456840179914546", -1, "2"},
|
||||
{"2.3025850929940456840179914546", -5, "2"},
|
||||
{"3.14159265359", 0, "3"},
|
||||
{"3.14159265359", 1, "3.1"},
|
||||
{"3.14159265359", 2, "3.141"},
|
||||
{"3.14159265359", 4, "3.1415926"},
|
||||
{"3.14159265359", 13, "3.14159265359"},
|
||||
} {
|
||||
ca := newConstApproximation(testCase.Const)
|
||||
expected, _ := NewFromString(testCase.ExpectedApproximation)
|
||||
|
||||
approximation := ca.withPrecision(testCase.Precision)
|
||||
|
||||
if approximation.Cmp(expected) != 0 {
|
||||
t.Errorf("expected approximation %s, got %s - for const with %s precision %d", testCase.ExpectedApproximation, approximation.String(), testCase.Const, testCase.Precision)
|
||||
}
|
||||
}
|
||||
}
|
426
decimal.go
426
decimal.go
|
@ -4,14 +4,14 @@
|
|||
//
|
||||
// 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"
|
||||
// n, err := decimal.NewFromString("-123.4567")
|
||||
// n.String() // output: "-123.4567"
|
||||
//
|
||||
// To use Decimal as part of a struct:
|
||||
//
|
||||
// type Struct struct {
|
||||
// Number Decimal
|
||||
// }
|
||||
// type StructName struct {
|
||||
// Number Decimal
|
||||
// }
|
||||
//
|
||||
// Note: This can "only" represent numbers with a maximum of 2^31 digits after the decimal point.
|
||||
package decimal
|
||||
|
@ -32,16 +32,15 @@ import (
|
|||
//
|
||||
// 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"
|
||||
//
|
||||
// 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 DivisionPrecision = 16
|
||||
|
||||
// MarshalJSONWithoutQuotes should be set to true if you want the decimal to
|
||||
|
@ -91,12 +90,12 @@ func New(value int64, exp int32) Decimal {
|
|||
}
|
||||
}
|
||||
|
||||
// NewFromInt converts a int64 to Decimal.
|
||||
// NewFromInt converts an int64 to Decimal.
|
||||
//
|
||||
// Example:
|
||||
//
|
||||
// NewFromInt(123).String() // output: "123"
|
||||
// NewFromInt(-10).String() // output: "-10"
|
||||
// NewFromInt(123).String() // output: "123"
|
||||
// NewFromInt(-10).String() // output: "-10"
|
||||
func NewFromInt(value int64) Decimal {
|
||||
return Decimal{
|
||||
value: big.NewInt(value),
|
||||
|
@ -104,12 +103,12 @@ func NewFromInt(value int64) Decimal {
|
|||
}
|
||||
}
|
||||
|
||||
// NewFromInt32 converts a int32 to Decimal.
|
||||
// NewFromInt32 converts an int32 to Decimal.
|
||||
//
|
||||
// Example:
|
||||
//
|
||||
// NewFromInt(123).String() // output: "123"
|
||||
// NewFromInt(-10).String() // output: "-10"
|
||||
// NewFromInt(123).String() // output: "123"
|
||||
// NewFromInt(-10).String() // output: "-10"
|
||||
func NewFromInt32(value int32) Decimal {
|
||||
return Decimal{
|
||||
value: big.NewInt(int64(value)),
|
||||
|
@ -125,15 +124,34 @@ func NewFromBigInt(value *big.Int, exp int32) Decimal {
|
|||
}
|
||||
}
|
||||
|
||||
// NewFromBigRat returns a new Decimal from a big.Rat. The numerator and
|
||||
// denominator are divided and rounded to the given precision.
|
||||
//
|
||||
// Example:
|
||||
//
|
||||
// d1 := NewFromBigRat(big.NewRat(0, 1), 0) // output: "0"
|
||||
// d2 := NewFromBigRat(big.NewRat(4, 5), 1) // output: "0.8"
|
||||
// d3 := NewFromBigRat(big.NewRat(1000, 3), 3) // output: "333.333"
|
||||
// d4 := NewFromBigRat(big.NewRat(2, 7), 4) // output: "0.2857"
|
||||
//
|
||||
func NewFromBigRat(value *big.Rat, precision int32) Decimal {
|
||||
return Decimal{
|
||||
value: new(big.Int).Set(value.Num()),
|
||||
exp: 0,
|
||||
}.DivRound(Decimal{
|
||||
value: new(big.Int).Set(value.Denom()),
|
||||
exp: 0,
|
||||
}, precision)
|
||||
}
|
||||
|
||||
// NewFromString returns a new Decimal from a string representation.
|
||||
// Trailing zeroes are not trimmed.
|
||||
//
|
||||
// Example:
|
||||
//
|
||||
// d, err := NewFromString("-123.45")
|
||||
// d2, err := NewFromString(".0001")
|
||||
// d3, err := NewFromString("1.47000")
|
||||
//
|
||||
// d, err := NewFromString("-123.45")
|
||||
// d2, err := NewFromString(".0001")
|
||||
// d3, err := NewFromString("1.47000")
|
||||
func NewFromString(value string) (Decimal, error) {
|
||||
originalInput := value
|
||||
var intString string
|
||||
|
@ -211,15 +229,14 @@ func NewFromString(value string) (Decimal, error) {
|
|||
//
|
||||
// Example:
|
||||
//
|
||||
// r := regexp.MustCompile("[$,]")
|
||||
// d1, err := NewFromFormattedString("$5,125.99", r)
|
||||
// r := regexp.MustCompile("[$,]")
|
||||
// d1, err := NewFromFormattedString("$5,125.99", r)
|
||||
//
|
||||
// r2 := regexp.MustCompile("[_]")
|
||||
// d2, err := NewFromFormattedString("1_000_000", r2)
|
||||
//
|
||||
// r3 := regexp.MustCompile("[USD\\s]")
|
||||
// d3, err := NewFromFormattedString("5000 USD", r3)
|
||||
// r2 := regexp.MustCompile("[_]")
|
||||
// d2, err := NewFromFormattedString("1_000_000", r2)
|
||||
//
|
||||
// r3 := regexp.MustCompile("[USD\\s]")
|
||||
// d3, err := NewFromFormattedString("5000 USD", r3)
|
||||
func NewFromFormattedString(value string, replRegexp *regexp.Regexp) (Decimal, error) {
|
||||
parsedValue := replRegexp.ReplaceAllString(value, "")
|
||||
d, err := NewFromString(parsedValue)
|
||||
|
@ -230,13 +247,12 @@ func NewFromFormattedString(value string, replRegexp *regexp.Regexp) (Decimal, e
|
|||
}
|
||||
|
||||
// RequireFromString returns a new Decimal from a string representation
|
||||
// or panics if NewFromString would have returned an error.
|
||||
// or panics if NewFromString had returned an error.
|
||||
//
|
||||
// Example:
|
||||
//
|
||||
// d := RequireFromString("-123.45")
|
||||
// d2 := RequireFromString(".0001")
|
||||
//
|
||||
// d := RequireFromString("-123.45")
|
||||
// d2 := RequireFromString(".0001")
|
||||
func RequireFromString(value string) Decimal {
|
||||
dec, err := NewFromString(value)
|
||||
if err != nil {
|
||||
|
@ -332,8 +348,7 @@ func newFromFloat(val float64, bits uint64, flt *floatInfo) Decimal {
|
|||
//
|
||||
// Example:
|
||||
//
|
||||
// NewFromFloatWithExponent(123.456, -2).String() // output: "123.46"
|
||||
//
|
||||
// NewFromFloatWithExponent(123.456, -2).String() // output: "123.46"
|
||||
func NewFromFloatWithExponent(value float64, exp int32) Decimal {
|
||||
if math.IsNaN(value) || math.IsInf(value, 0) {
|
||||
panic(fmt.Sprintf("Cannot create a Decimal from %v", value))
|
||||
|
@ -418,7 +433,7 @@ func NewFromFloatWithExponent(value float64, exp int32) Decimal {
|
|||
func (d Decimal) Copy() Decimal {
|
||||
d.ensureInitialized()
|
||||
return Decimal{
|
||||
value: &(*d.value),
|
||||
value: new(big.Int).Set(d.value),
|
||||
exp: d.exp,
|
||||
}
|
||||
}
|
||||
|
@ -430,7 +445,7 @@ func (d Decimal) Copy() Decimal {
|
|||
//
|
||||
// Example:
|
||||
//
|
||||
// d := New(12345, -4)
|
||||
// d := New(12345, -4)
|
||||
// d2 := d.rescale(-1)
|
||||
// d3 := d2.rescale(-4)
|
||||
// println(d1)
|
||||
|
@ -442,7 +457,6 @@ func (d Decimal) Copy() Decimal {
|
|||
// 1.2345
|
||||
// 1.2
|
||||
// 1.2000
|
||||
//
|
||||
func (d Decimal) rescale(exp int32) Decimal {
|
||||
d.ensureInitialized()
|
||||
|
||||
|
@ -554,9 +568,11 @@ func (d Decimal) Div(d2 Decimal) Decimal {
|
|||
|
||||
// QuoRem does division 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
|
||||
//
|
||||
// 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 (d Decimal) QuoRem(d2 Decimal, precision int32) (Decimal, Decimal) {
|
||||
d.ensureInitialized()
|
||||
|
@ -565,7 +581,7 @@ func (d Decimal) QuoRem(d2 Decimal, precision int32) (Decimal, Decimal) {
|
|||
panic("decimal division by 0")
|
||||
}
|
||||
scale := -precision
|
||||
e := int64(d.exp - d2.exp - scale)
|
||||
e := int64(d.exp) - int64(d2.exp) - int64(scale)
|
||||
if e > math.MaxInt32 || e < math.MinInt32 {
|
||||
panic("overflow in decimal QuoRem")
|
||||
}
|
||||
|
@ -599,8 +615,10 @@ func (d Decimal) QuoRem(d2 Decimal, precision int32) (Decimal, 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
|
||||
//
|
||||
// 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 (d Decimal) DivRound(d2 Decimal, precision int32) Decimal {
|
||||
// QuoRem already checks initialization
|
||||
|
@ -628,8 +646,8 @@ func (d Decimal) DivRound(d2 Decimal, precision int32) Decimal {
|
|||
|
||||
// Mod returns d % d2.
|
||||
func (d Decimal) Mod(d2 Decimal) Decimal {
|
||||
quo := d.DivRound(d2, -d.exp+1).Truncate(0)
|
||||
return d.Sub(d2.Mul(quo))
|
||||
_, r := d.QuoRem(d2, 0)
|
||||
return r
|
||||
}
|
||||
|
||||
// Pow returns d to the power d2
|
||||
|
@ -655,9 +673,8 @@ func (d Decimal) Pow(d2 Decimal) Decimal {
|
|||
//
|
||||
// Example:
|
||||
//
|
||||
// NewFromFloat(26.1).ExpHullAbrham(2).String() // output: "220000000000"
|
||||
// NewFromFloat(26.1).ExpHullAbrham(20).String() // output: "216314672147.05767284"
|
||||
//
|
||||
// NewFromFloat(26.1).ExpHullAbrham(2).String() // output: "220000000000"
|
||||
// NewFromFloat(26.1).ExpHullAbrham(20).String() // output: "216314672147.05767284"
|
||||
func (d Decimal) ExpHullAbrham(overallPrecision uint32) (Decimal, error) {
|
||||
// Algorithm based on Variable precision exponential function.
|
||||
// ACM Transactions on Mathematical Software by T. E. Hull & A. Abrham.
|
||||
|
@ -747,15 +764,14 @@ func (d Decimal) ExpHullAbrham(overallPrecision uint32) (Decimal, error) {
|
|||
//
|
||||
// Example:
|
||||
//
|
||||
// d, err := NewFromFloat(26.1).ExpTaylor(2).String()
|
||||
// d.String() // output: "216314672147.06"
|
||||
// d, err := NewFromFloat(26.1).ExpTaylor(2).String()
|
||||
// d.String() // output: "216314672147.06"
|
||||
//
|
||||
// NewFromFloat(26.1).ExpTaylor(20).String()
|
||||
// d.String() // output: "216314672147.05767284062928674083"
|
||||
//
|
||||
// NewFromFloat(26.1).ExpTaylor(-10).String()
|
||||
// d.String() // output: "220000000000"
|
||||
// NewFromFloat(26.1).ExpTaylor(20).String()
|
||||
// d.String() // output: "216314672147.05767284062928674083"
|
||||
//
|
||||
// NewFromFloat(26.1).ExpTaylor(-10).String()
|
||||
// d.String() // output: "220000000000"
|
||||
func (d Decimal) ExpTaylor(precision int32) (Decimal, error) {
|
||||
// Note(mwoss): Implementation can be optimized by exclusively using big.Int API only
|
||||
if d.IsZero() {
|
||||
|
@ -812,9 +828,127 @@ func (d Decimal) ExpTaylor(precision int32) (Decimal, error) {
|
|||
return result, nil
|
||||
}
|
||||
|
||||
// Ln calculates natural logarithm of d.
|
||||
// Precision argument specifies how precise the result must be (number of digits after decimal point).
|
||||
// Negative precision is allowed.
|
||||
//
|
||||
// Example:
|
||||
//
|
||||
// d1, err := NewFromFloat(13.3).Ln(2)
|
||||
// d1.String() // output: "2.59"
|
||||
//
|
||||
// d2, err := NewFromFloat(579.161).Ln(10)
|
||||
// d2.String() // output: "6.3615805046"
|
||||
func (d Decimal) Ln(precision int32) (Decimal, error) {
|
||||
// Algorithm based on The Use of Iteration Methods for Approximating the Natural Logarithm,
|
||||
// James F. Epperson, The American Mathematical Monthly, Vol. 96, No. 9, November 1989, pp. 831-835.
|
||||
if d.IsNegative() {
|
||||
return Decimal{}, fmt.Errorf("cannot calculate natural logarithm for negative decimals")
|
||||
}
|
||||
|
||||
if d.IsZero() {
|
||||
return Decimal{}, fmt.Errorf("cannot represent natural logarithm of 0, result: -infinity")
|
||||
}
|
||||
|
||||
calcPrecision := precision + 2
|
||||
z := d.Copy()
|
||||
|
||||
var comp1, comp3, comp2, comp4, reduceAdjust Decimal
|
||||
comp1 = z.Sub(Decimal{oneInt, 0})
|
||||
comp3 = Decimal{oneInt, -1}
|
||||
|
||||
// for decimal in range [0.9, 1.1] where ln(d) is close to 0
|
||||
usePowerSeries := false
|
||||
|
||||
if comp1.Abs().Cmp(comp3) <= 0 {
|
||||
usePowerSeries = true
|
||||
} else {
|
||||
// reduce input decimal to range [0.1, 1)
|
||||
expDelta := int32(z.NumDigits()) + z.exp
|
||||
z.exp -= expDelta
|
||||
|
||||
// Input decimal was reduced by factor of 10^expDelta, thus we will need to add
|
||||
// ln(10^expDelta) = expDelta * ln(10)
|
||||
// to the result to compensate that
|
||||
ln10 := ln10.withPrecision(calcPrecision)
|
||||
reduceAdjust = NewFromInt32(expDelta)
|
||||
reduceAdjust = reduceAdjust.Mul(ln10)
|
||||
|
||||
comp1 = z.Sub(Decimal{oneInt, 0})
|
||||
|
||||
if comp1.Abs().Cmp(comp3) <= 0 {
|
||||
usePowerSeries = true
|
||||
} else {
|
||||
// initial estimate using floats
|
||||
zFloat := z.InexactFloat64()
|
||||
comp1 = NewFromFloat(math.Log(zFloat))
|
||||
}
|
||||
}
|
||||
|
||||
epsilon := Decimal{oneInt, -calcPrecision}
|
||||
|
||||
if usePowerSeries {
|
||||
// Power Series - https://en.wikipedia.org/wiki/Logarithm#Power_series
|
||||
// Calculating n-th term of formula: ln(z+1) = 2 sum [ 1 / (2n+1) * (z / (z+2))^(2n+1) ]
|
||||
// until the difference between current and next term is smaller than epsilon.
|
||||
// Coverage quite fast for decimals close to 1.0
|
||||
|
||||
// z + 2
|
||||
comp2 = comp1.Add(Decimal{twoInt, 0})
|
||||
// z / (z + 2)
|
||||
comp3 = comp1.DivRound(comp2, calcPrecision)
|
||||
// 2 * (z / (z + 2))
|
||||
comp1 = comp3.Add(comp3)
|
||||
comp2 = comp1.Copy()
|
||||
|
||||
for n := 1; ; n++ {
|
||||
// 2 * (z / (z+2))^(2n+1)
|
||||
comp2 = comp2.Mul(comp3).Mul(comp3)
|
||||
|
||||
// 1 / (2n+1) * 2 * (z / (z+2))^(2n+1)
|
||||
comp4 = NewFromInt(int64(2*n + 1))
|
||||
comp4 = comp2.DivRound(comp4, calcPrecision)
|
||||
|
||||
// comp1 = 2 sum [ 1 / (2n+1) * (z / (z+2))^(2n+1) ]
|
||||
comp1 = comp1.Add(comp4)
|
||||
|
||||
if comp4.Abs().Cmp(epsilon) <= 0 {
|
||||
break
|
||||
}
|
||||
}
|
||||
} else {
|
||||
// Halley's Iteration.
|
||||
// Calculating n-th term of formula: a_(n+1) = a_n - 2 * (exp(a_n) - z) / (exp(a_n) + z),
|
||||
// until the difference between current and next term is smaller than epsilon
|
||||
for {
|
||||
// exp(a_n)
|
||||
comp3, _ = comp1.ExpTaylor(calcPrecision)
|
||||
// exp(a_n) - z
|
||||
comp2 = comp3.Sub(z)
|
||||
// 2 * (exp(a_n) - z)
|
||||
comp2 = comp2.Add(comp2)
|
||||
// exp(a_n) + z
|
||||
comp4 = comp3.Add(z)
|
||||
// 2 * (exp(a_n) - z) / (exp(a_n) + z)
|
||||
comp3 = comp2.DivRound(comp4, calcPrecision)
|
||||
// comp1 = a_(n+1) = a_n - 2 * (exp(a_n) - z) / (exp(a_n) + z)
|
||||
comp1 = comp1.Sub(comp3)
|
||||
|
||||
if comp3.Abs().Cmp(epsilon) <= 0 {
|
||||
break
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
comp1 = comp1.Add(reduceAdjust)
|
||||
|
||||
return comp1.Round(precision), nil
|
||||
}
|
||||
|
||||
// NumDigits returns the number of digits of the decimal coefficient (d.Value)
|
||||
// Note: Current implementation is extremely slow for large decimals and/or decimals with large fractional part
|
||||
func (d Decimal) NumDigits() int {
|
||||
d.ensureInitialized()
|
||||
// Note(mwoss): It can be optimized, unnecessary cast of big.Int to string
|
||||
if d.IsNegative() {
|
||||
return len(d.value.String()) - 1
|
||||
|
@ -851,10 +985,9 @@ func abs(n int32) int32 {
|
|||
|
||||
// Cmp compares the numbers represented by d and d2 and returns:
|
||||
//
|
||||
// -1 if d < d2
|
||||
// 0 if d == d2
|
||||
// +1 if d > d2
|
||||
//
|
||||
// -1 if d < d2
|
||||
// 0 if d == d2
|
||||
// +1 if d > d2
|
||||
func (d Decimal) Cmp(d2 Decimal) int {
|
||||
d.ensureInitialized()
|
||||
d2.ensureInitialized()
|
||||
|
@ -868,12 +1001,21 @@ func (d Decimal) Cmp(d2 Decimal) int {
|
|||
return rd.value.Cmp(rd2.value)
|
||||
}
|
||||
|
||||
// Compare compares the numbers represented by d and d2 and returns:
|
||||
//
|
||||
// -1 if d < d2
|
||||
// 0 if d == d2
|
||||
// +1 if d > d2
|
||||
func (d Decimal) Compare(d2 Decimal) int {
|
||||
return d.Cmp(d2)
|
||||
}
|
||||
|
||||
// Equal returns whether the numbers represented by d and d2 are equal.
|
||||
func (d Decimal) Equal(d2 Decimal) bool {
|
||||
return d.Cmp(d2) == 0
|
||||
}
|
||||
|
||||
// Equals is deprecated, please use Equal method instead
|
||||
// Deprecated: Equals is deprecated, please use Equal method instead.
|
||||
func (d Decimal) Equals(d2 Decimal) bool {
|
||||
return d.Equal(d2)
|
||||
}
|
||||
|
@ -905,7 +1047,6 @@ func (d Decimal) LessThanOrEqual(d2 Decimal) bool {
|
|||
// -1 if d < 0
|
||||
// 0 if d == 0
|
||||
// +1 if d > 0
|
||||
//
|
||||
func (d Decimal) Sign() int {
|
||||
if d.value == nil {
|
||||
return 0
|
||||
|
@ -1014,13 +1155,12 @@ func (d Decimal) InexactFloat64() float64 {
|
|||
//
|
||||
// Example:
|
||||
//
|
||||
// d := New(-12345, -3)
|
||||
// println(d.String())
|
||||
// d := New(-12345, -3)
|
||||
// println(d.String())
|
||||
//
|
||||
// Output:
|
||||
//
|
||||
// -12.345
|
||||
//
|
||||
// -12.345
|
||||
func (d Decimal) String() string {
|
||||
return d.string(true)
|
||||
}
|
||||
|
@ -1030,14 +1170,13 @@ func (d Decimal) String() string {
|
|||
//
|
||||
// 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"
|
||||
//
|
||||
// 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 (d Decimal) StringFixed(places int32) string {
|
||||
rounded := d.Round(places)
|
||||
return rounded.string(false)
|
||||
|
@ -1048,14 +1187,13 @@ func (d Decimal) StringFixed(places int32) string {
|
|||
//
|
||||
// Example:
|
||||
//
|
||||
// NewFromFloat(0).StringFixedBank(2) // output: "0.00"
|
||||
// NewFromFloat(0).StringFixedBank(0) // output: "0"
|
||||
// NewFromFloat(5.45).StringFixedBank(0) // output: "5"
|
||||
// NewFromFloat(5.45).StringFixedBank(1) // output: "5.4"
|
||||
// NewFromFloat(5.45).StringFixedBank(2) // output: "5.45"
|
||||
// NewFromFloat(5.45).StringFixedBank(3) // output: "5.450"
|
||||
// NewFromFloat(545).StringFixedBank(-1) // output: "540"
|
||||
//
|
||||
// NewFromFloat(0).StringFixedBank(2) // output: "0.00"
|
||||
// NewFromFloat(0).StringFixedBank(0) // output: "0"
|
||||
// NewFromFloat(5.45).StringFixedBank(0) // output: "5"
|
||||
// NewFromFloat(5.45).StringFixedBank(1) // output: "5.4"
|
||||
// NewFromFloat(5.45).StringFixedBank(2) // output: "5.45"
|
||||
// NewFromFloat(5.45).StringFixedBank(3) // output: "5.450"
|
||||
// NewFromFloat(545).StringFixedBank(-1) // output: "540"
|
||||
func (d Decimal) StringFixedBank(places int32) string {
|
||||
rounded := d.RoundBank(places)
|
||||
return rounded.string(false)
|
||||
|
@ -1073,9 +1211,8 @@ func (d Decimal) StringFixedCash(interval uint8) string {
|
|||
//
|
||||
// Example:
|
||||
//
|
||||
// NewFromFloat(5.45).Round(1).String() // output: "5.5"
|
||||
// NewFromFloat(545).Round(-1).String() // output: "550"
|
||||
//
|
||||
// NewFromFloat(5.45).Round(1).String() // output: "5.5"
|
||||
// NewFromFloat(545).Round(-1).String() // output: "550"
|
||||
func (d Decimal) Round(places int32) Decimal {
|
||||
if d.exp == -places {
|
||||
return d
|
||||
|
@ -1104,11 +1241,10 @@ func (d Decimal) Round(places int32) Decimal {
|
|||
//
|
||||
// Example:
|
||||
//
|
||||
// NewFromFloat(545).RoundCeil(-2).String() // output: "600"
|
||||
// NewFromFloat(500).RoundCeil(-2).String() // output: "500"
|
||||
// NewFromFloat(1.1001).RoundCeil(2).String() // output: "1.11"
|
||||
// NewFromFloat(-1.454).RoundCeil(1).String() // output: "-1.5"
|
||||
//
|
||||
// NewFromFloat(545).RoundCeil(-2).String() // output: "600"
|
||||
// NewFromFloat(500).RoundCeil(-2).String() // output: "500"
|
||||
// NewFromFloat(1.1001).RoundCeil(2).String() // output: "1.11"
|
||||
// NewFromFloat(-1.454).RoundCeil(1).String() // output: "-1.4"
|
||||
func (d Decimal) RoundCeil(places int32) Decimal {
|
||||
if d.exp >= -places {
|
||||
return d
|
||||
|
@ -1130,11 +1266,10 @@ func (d Decimal) RoundCeil(places int32) Decimal {
|
|||
//
|
||||
// Example:
|
||||
//
|
||||
// NewFromFloat(545).RoundFloor(-2).String() // output: "500"
|
||||
// NewFromFloat(-500).RoundFloor(-2).String() // output: "-500"
|
||||
// NewFromFloat(1.1001).RoundFloor(2).String() // output: "1.1"
|
||||
// NewFromFloat(-1.454).RoundFloor(1).String() // output: "-1.4"
|
||||
//
|
||||
// NewFromFloat(545).RoundFloor(-2).String() // output: "500"
|
||||
// NewFromFloat(-500).RoundFloor(-2).String() // output: "-500"
|
||||
// NewFromFloat(1.1001).RoundFloor(2).String() // output: "1.1"
|
||||
// NewFromFloat(-1.454).RoundFloor(1).String() // output: "-1.5"
|
||||
func (d Decimal) RoundFloor(places int32) Decimal {
|
||||
if d.exp >= -places {
|
||||
return d
|
||||
|
@ -1156,11 +1291,10 @@ func (d Decimal) RoundFloor(places int32) Decimal {
|
|||
//
|
||||
// Example:
|
||||
//
|
||||
// NewFromFloat(545).RoundUp(-2).String() // output: "600"
|
||||
// NewFromFloat(500).RoundUp(-2).String() // output: "500"
|
||||
// NewFromFloat(1.1001).RoundUp(2).String() // output: "1.11"
|
||||
// NewFromFloat(-1.454).RoundUp(1).String() // output: "-1.4"
|
||||
//
|
||||
// NewFromFloat(545).RoundUp(-2).String() // output: "600"
|
||||
// NewFromFloat(500).RoundUp(-2).String() // output: "500"
|
||||
// NewFromFloat(1.1001).RoundUp(2).String() // output: "1.11"
|
||||
// NewFromFloat(-1.454).RoundUp(1).String() // output: "-1.5"
|
||||
func (d Decimal) RoundUp(places int32) Decimal {
|
||||
if d.exp >= -places {
|
||||
return d
|
||||
|
@ -1184,11 +1318,10 @@ func (d Decimal) RoundUp(places int32) Decimal {
|
|||
//
|
||||
// Example:
|
||||
//
|
||||
// NewFromFloat(545).RoundDown(-2).String() // output: "500"
|
||||
// NewFromFloat(-500).RoundDown(-2).String() // output: "-500"
|
||||
// NewFromFloat(1.1001).RoundDown(2).String() // output: "1.1"
|
||||
// NewFromFloat(-1.454).RoundDown(1).String() // output: "-1.5"
|
||||
//
|
||||
// NewFromFloat(545).RoundDown(-2).String() // output: "500"
|
||||
// NewFromFloat(-500).RoundDown(-2).String() // output: "-500"
|
||||
// NewFromFloat(1.1001).RoundDown(2).String() // output: "1.1"
|
||||
// NewFromFloat(-1.454).RoundDown(1).String() // output: "-1.4"
|
||||
func (d Decimal) RoundDown(places int32) Decimal {
|
||||
if d.exp >= -places {
|
||||
return d
|
||||
|
@ -1209,13 +1342,12 @@ func (d Decimal) RoundDown(places int32) Decimal {
|
|||
//
|
||||
// Examples:
|
||||
//
|
||||
// NewFromFloat(5.45).RoundBank(1).String() // output: "5.4"
|
||||
// NewFromFloat(545).RoundBank(-1).String() // output: "540"
|
||||
// NewFromFloat(5.46).RoundBank(1).String() // output: "5.5"
|
||||
// NewFromFloat(546).RoundBank(-1).String() // output: "550"
|
||||
// NewFromFloat(5.55).RoundBank(1).String() // output: "5.6"
|
||||
// NewFromFloat(555).RoundBank(-1).String() // output: "560"
|
||||
//
|
||||
// NewFromFloat(5.45).RoundBank(1).String() // output: "5.4"
|
||||
// NewFromFloat(545).RoundBank(-1).String() // output: "540"
|
||||
// NewFromFloat(5.46).RoundBank(1).String() // output: "5.5"
|
||||
// NewFromFloat(546).RoundBank(-1).String() // output: "550"
|
||||
// NewFromFloat(5.55).RoundBank(1).String() // output: "5.6"
|
||||
// NewFromFloat(555).RoundBank(-1).String() // output: "560"
|
||||
func (d Decimal) RoundBank(places int32) Decimal {
|
||||
|
||||
round := d.Round(places)
|
||||
|
@ -1237,11 +1369,13 @@ func (d Decimal) RoundBank(places int32) Decimal {
|
|||
// 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, 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)
|
||||
// 25: 25 cent rounding 3.41 => 3.50
|
||||
// 50: 50 cent rounding 3.75 => 4.00
|
||||
// 100: 100 cent rounding 3.50 => 4.00
|
||||
//
|
||||
// 5: 5 cent rounding 3.43 => 3.45
|
||||
// 10: 10 cent rounding 3.45 => 3.50 (5 gets rounded up)
|
||||
// 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 (d Decimal) RoundCash(interval uint8) Decimal {
|
||||
var iVal *big.Int
|
||||
|
@ -1310,8 +1444,7 @@ func (d Decimal) Ceil() Decimal {
|
|||
//
|
||||
// Example:
|
||||
//
|
||||
// decimal.NewFromString("123.456").Truncate(2).String() // "123.45"
|
||||
//
|
||||
// decimal.NewFromString("123.456").Truncate(2).String() // "123.45"
|
||||
func (d Decimal) Truncate(precision int32) Decimal {
|
||||
d.ensureInitialized()
|
||||
if precision >= 0 && -precision > d.exp {
|
||||
|
@ -1402,6 +1535,26 @@ func (d *Decimal) Scan(value interface{}) error {
|
|||
*d = NewFromFloat(v)
|
||||
return nil
|
||||
|
||||
case int:
|
||||
// also better to implement to support all type of int.
|
||||
// profitable to create another abstract layer for testing
|
||||
// data access with no depends on real RDBMS.
|
||||
|
||||
*d = New(int64(v), 0)
|
||||
return nil
|
||||
|
||||
case int8:
|
||||
*d = New(int64(v), 0)
|
||||
return nil
|
||||
|
||||
case int16:
|
||||
*d = New(int64(v), 0)
|
||||
return nil
|
||||
|
||||
case int32:
|
||||
*d = New(int64(v), 0)
|
||||
return nil
|
||||
|
||||
case int64:
|
||||
// at least in sqlite3 when the value is 0 in db, the data is sent
|
||||
// to us as an int64 instead of a float64 ...
|
||||
|
@ -1455,7 +1608,8 @@ func (d *Decimal) GobDecode(data []byte) error {
|
|||
}
|
||||
|
||||
// StringScaled first scales the decimal then calls .String() on it.
|
||||
// NOTE: buggy, unintuitive, and DEPRECATED! Use StringFixed instead.
|
||||
//
|
||||
// Deprecated: buggy and unintuitive. Use StringFixed instead.
|
||||
func (d Decimal) StringScaled(exp int32) string {
|
||||
return d.rescale(exp).String()
|
||||
}
|
||||
|
@ -1515,7 +1669,7 @@ func (d *Decimal) ensureInitialized() {
|
|||
//
|
||||
// To call this function with an array, you must do:
|
||||
//
|
||||
// Min(arr[0], arr[1:]...)
|
||||
// Min(arr[0], arr[1:]...)
|
||||
//
|
||||
// This makes it harder to accidentally call Min with 0 arguments.
|
||||
func Min(first Decimal, rest ...Decimal) Decimal {
|
||||
|
@ -1532,7 +1686,7 @@ func Min(first Decimal, rest ...Decimal) Decimal {
|
|||
//
|
||||
// To call this function with an array, you must do:
|
||||
//
|
||||
// Max(arr[0], arr[1:]...)
|
||||
// Max(arr[0], arr[1:]...)
|
||||
//
|
||||
// This makes it harder to accidentally call Max with 0 arguments.
|
||||
func Max(first Decimal, rest ...Decimal) Decimal {
|
||||
|
@ -1567,22 +1721,13 @@ func RescalePair(d1 Decimal, d2 Decimal) (Decimal, Decimal) {
|
|||
d1.ensureInitialized()
|
||||
d2.ensureInitialized()
|
||||
|
||||
if d1.exp == d2.exp {
|
||||
return d1, d2
|
||||
if d1.exp < d2.exp {
|
||||
return d1, d2.rescale(d1.exp)
|
||||
} else if d1.exp > d2.exp {
|
||||
return d1.rescale(d2.exp), d2
|
||||
}
|
||||
|
||||
baseScale := min(d1.exp, d2.exp)
|
||||
if baseScale != d1.exp {
|
||||
return d1.rescale(baseScale), d2
|
||||
}
|
||||
return d1, d2.rescale(baseScale)
|
||||
}
|
||||
|
||||
func min(x, y int32) int32 {
|
||||
if x >= y {
|
||||
return y
|
||||
}
|
||||
return x
|
||||
return d1, d2
|
||||
}
|
||||
|
||||
func unquoteIfQuoted(value interface{}) (string, error) {
|
||||
|
@ -1594,8 +1739,7 @@ func unquoteIfQuoted(value interface{}) (string, error) {
|
|||
case []byte:
|
||||
bytes = v
|
||||
default:
|
||||
return "", fmt.Errorf("could not convert value '%+v' to byte array of type '%T'",
|
||||
value, value)
|
||||
return "", fmt.Errorf("could not convert value '%+v' to byte array of type '%T'", value, value)
|
||||
}
|
||||
|
||||
// If the amount is quoted, strip the quotes
|
||||
|
|
173
decimal_test.go
173
decimal_test.go
|
@ -556,10 +556,59 @@ func TestNewFromBigIntWithExponent(t *testing.T) {
|
|||
}
|
||||
}
|
||||
|
||||
func TestNewFromBigRat(t *testing.T) {
|
||||
mustParseRat := func(val string) *big.Rat {
|
||||
num, _ := new(big.Rat).SetString(val)
|
||||
return num
|
||||
}
|
||||
|
||||
type Inp struct {
|
||||
val *big.Rat
|
||||
prec int32
|
||||
}
|
||||
|
||||
tests := map[Inp]string{
|
||||
Inp{big.NewRat(0, 1), 16}: "0",
|
||||
Inp{big.NewRat(4, 5), 16}: "0.8",
|
||||
Inp{big.NewRat(10, 2), 16}: "5",
|
||||
Inp{big.NewRat(1023427554493, 43432632), 16}: "23563.5628642767953828", // rounded
|
||||
Inp{big.NewRat(1, 434324545566634), 16}: "0.0000000000000023",
|
||||
Inp{big.NewRat(1, 3), 16}: "0.3333333333333333",
|
||||
Inp{big.NewRat(2, 3), 2}: "0.67", // rounded
|
||||
Inp{big.NewRat(2, 3), 16}: "0.6666666666666667", // rounded
|
||||
Inp{big.NewRat(10000, 3), 16}: "3333.3333333333333333",
|
||||
Inp{mustParseRat("30702832066636633479"), 16}: "30702832066636633479",
|
||||
Inp{mustParseRat("487028320159896636679.1827512895753"), 16}: "487028320159896636679.1827512895753",
|
||||
Inp{mustParseRat("127028320612589896636633479.173582751289575278357832"), -2}: "127028320612589896636633500", // rounded
|
||||
Inp{mustParseRat("127028320612589896636633479.173582751289575278357832"), 16}: "127028320612589896636633479.1735827512895753", // rounded
|
||||
Inp{mustParseRat("127028320612589896636633479.173582751289575278357832"), 32}: "127028320612589896636633479.173582751289575278357832",
|
||||
}
|
||||
|
||||
// add negatives
|
||||
for p, s := range tests {
|
||||
if p.val.Cmp(new(big.Rat)) > 0 {
|
||||
tests[Inp{p.val.Neg(p.val), p.prec}] = "-" + s
|
||||
}
|
||||
}
|
||||
|
||||
for input, s := range tests {
|
||||
d := NewFromBigRat(input.val, input.prec)
|
||||
if d.String() != s {
|
||||
t.Errorf("expected %s, got %s (%s, %d)",
|
||||
s, d.String(),
|
||||
d.value.String(), d.exp)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestCopy(t *testing.T) {
|
||||
origin := New(1, 0)
|
||||
cpy := origin.Copy()
|
||||
|
||||
if origin.value == cpy.value {
|
||||
t.Error("expecting copy and origin to have different value pointers")
|
||||
}
|
||||
|
||||
if cpy.Cmp(origin) != 0 {
|
||||
t.Error("expecting copy and origin to be equals, but they are not")
|
||||
}
|
||||
|
@ -2143,6 +2192,8 @@ func TestDecimal_Mod(t *testing.T) {
|
|||
Inp{"-7.5", "2"}: "-1.5",
|
||||
Inp{"7.5", "-2"}: "1.5",
|
||||
Inp{"-7.5", "-2"}: "-1.5",
|
||||
Inp{"41", "21"}: "20",
|
||||
Inp{"400000000001", "200000000001"}: "200000000000",
|
||||
}
|
||||
|
||||
for inp, res := range inputs {
|
||||
|
@ -2446,6 +2497,66 @@ func TestDecimal_Scan(t *testing.T) {
|
|||
if err == nil {
|
||||
t.Errorf("a.Scan(Foo{}) should have thrown an error but did not")
|
||||
}
|
||||
|
||||
dbvalueInt8 := int8(32)
|
||||
expected = New(int64(32), 0)
|
||||
|
||||
err = a.Scan(dbvalueInt8)
|
||||
if err != nil {
|
||||
// Scan failed... no need to test result value
|
||||
t.Errorf("a.Scan(32) failed with message: %s", err)
|
||||
|
||||
} else {
|
||||
// Scan succeeded... test resulting values
|
||||
if !a.Equal(expected) {
|
||||
t.Errorf("%s does not equal to %s", a, expected)
|
||||
}
|
||||
}
|
||||
|
||||
dbvalueInt16 := int16(21)
|
||||
expected = New(int64(21), 0)
|
||||
|
||||
err = a.Scan(dbvalueInt16)
|
||||
if err != nil {
|
||||
// Scan failed... no need to test result value
|
||||
t.Errorf("a.Scan(21) failed with message: %s", err)
|
||||
|
||||
} else {
|
||||
// Scan succeeded... test resulting values
|
||||
if !a.Equal(expected) {
|
||||
t.Errorf("%s does not equal to %s", a, expected)
|
||||
}
|
||||
}
|
||||
|
||||
dbvalueInt32 := int32(32)
|
||||
expected = New(int64(32), 0)
|
||||
|
||||
err = a.Scan(dbvalueInt32)
|
||||
if err != nil {
|
||||
// Scan failed... no need to test result value
|
||||
t.Errorf("a.Scan(32) failed with message: %s", err)
|
||||
|
||||
} else {
|
||||
// Scan succeeded... test resulting values
|
||||
if !a.Equal(expected) {
|
||||
t.Errorf("%s does not equal to %s", a, expected)
|
||||
}
|
||||
}
|
||||
|
||||
dbvalueIntNatural := 3264
|
||||
expected = New(int64(3264), 0)
|
||||
|
||||
err = a.Scan(dbvalueIntNatural)
|
||||
if err != nil {
|
||||
// Scan failed... no need to test result value
|
||||
t.Errorf("a.Scan(3264) failed with message: %s", err)
|
||||
|
||||
} else {
|
||||
// Scan succeeded... test resulting values
|
||||
if !a.Equal(expected) {
|
||||
t.Errorf("%s does not equal to %s", a, expected)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestDecimal_Value(t *testing.T) {
|
||||
|
@ -2745,6 +2856,67 @@ func TestDecimal_ExpTaylor(t *testing.T) {
|
|||
}
|
||||
}
|
||||
|
||||
func TestDecimal_Ln(t *testing.T) {
|
||||
for _, testCase := range []struct {
|
||||
Dec string
|
||||
Precision int32
|
||||
Expected string
|
||||
}{
|
||||
{"0.1", 25, "-2.3025850929940456840179915"},
|
||||
{"0.01", 25, "-4.6051701859880913680359829"},
|
||||
{"0.001", 25, "-6.9077552789821370520539744"},
|
||||
{"0.00000001", 25, "-18.4206807439523654721439316"},
|
||||
{"1.0", 10, "0.0"},
|
||||
{"1.01", 25, "0.0099503308531680828482154"},
|
||||
{"1.001", 25, "0.0009995003330835331668094"},
|
||||
{"1.0001", 25, "0.0000999950003333083353332"},
|
||||
{"1.1", 25, "0.0953101798043248600439521"},
|
||||
{"1.13", 25, "0.1222176327242492005461486"},
|
||||
{"3.13", 10, "1.1410330046"},
|
||||
{"3.13", 25, "1.1410330045520618486427824"},
|
||||
{"3.13", 50, "1.14103300455206184864278239988848193837089629107972"},
|
||||
{"3.13", 100, "1.1410330045520618486427823998884819383708962910797239760817078430268177216960996098918971117211892839"},
|
||||
{"5.71", 25, "1.7422190236679188486939833"},
|
||||
{"5.7185108151957193571930205", 50, "1.74370842450178929149992165925283704012576949094645"},
|
||||
{"839101.0351", 25, "13.6400864014410013994397240"},
|
||||
{"839101.0351094726488848490572028502", 50, "13.64008640145229044389152437468283605382056561604272"},
|
||||
{"5023583755703750094849.03519358513093500275017501750602739169823", 25, "49.9684305274348922267409953"},
|
||||
{"5023583755703750094849.03519358513093500275017501750602739169823", -1, "50.0"},
|
||||
} {
|
||||
d, _ := NewFromString(testCase.Dec)
|
||||
expected, _ := NewFromString(testCase.Expected)
|
||||
|
||||
ln, err := d.Ln(testCase.Precision)
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
|
||||
if ln.Cmp(expected) != 0 {
|
||||
t.Errorf("expected %s, got %s, for decimal %s", testCase.Expected, ln.String(), testCase.Dec)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func TestDecimal_LnZero(t *testing.T) {
|
||||
d := New(0, 0)
|
||||
|
||||
_, err := d.Ln(5)
|
||||
|
||||
if err == nil {
|
||||
t.Errorf("expected error, natural logarithm of 0 cannot be represented (-infinity)")
|
||||
}
|
||||
}
|
||||
|
||||
func TestDecimal_LnNegative(t *testing.T) {
|
||||
d := New(-20, 2)
|
||||
|
||||
_, err := d.Ln(5)
|
||||
|
||||
if err == nil {
|
||||
t.Errorf("expected error, natural logarithm cannot be calculated for nagative decimals")
|
||||
}
|
||||
}
|
||||
|
||||
func TestDecimal_NumDigits(t *testing.T) {
|
||||
for _, testCase := range []struct {
|
||||
Dec string
|
||||
|
@ -2764,6 +2936,7 @@ func TestDecimal_NumDigits(t *testing.T) {
|
|||
{"-5.26", 3},
|
||||
{"-5.2663117716", 11},
|
||||
{"-26.1", 3},
|
||||
{"", 1},
|
||||
} {
|
||||
d, _ := NewFromString(testCase.Dec)
|
||||
|
||||
|
|
2
go.mod
2
go.mod
|
@ -1,3 +1,3 @@
|
|||
module github.com/shopspring/decimal
|
||||
|
||||
go 1.13
|
||||
go 1.7
|
||||
|
|
Loading…
Reference in a new issue