diff --git a/decimal.go b/decimal.go index c614ea79..4f9df0e7 100644 --- a/decimal.go +++ b/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 Struct 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 @@ -95,8 +94,8 @@ func New(value int64, exp int32) 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), @@ -108,8 +107,8 @@ func NewFromInt(value int64) 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)), @@ -130,10 +129,9 @@ func NewFromBigInt(value *big.Int, exp int32) Decimal { // // 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 +209,14 @@ 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) @@ -234,9 +231,8 @@ func NewFromFormattedString(value string, replRegexp *regexp.Regexp) (Decimal, e // // 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 +328,7 @@ 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)) @@ -430,7 +425,7 @@ 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 +437,6 @@ func (d Decimal) Copy() Decimal { // 1.2345 // 1.2 // 1.2000 -// func (d Decimal) rescale(exp int32) Decimal { d.ensureInitialized() @@ -554,9 +548,11 @@ 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() @@ -599,8 +595,10 @@ 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 @@ -655,9 +653,8 @@ 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 +744,14 @@ func (d Decimal) ExpHullAbrham(overallPrecision uint32) (Decimal, error) { // // Example: // -// d, err := NewFromFloat(26.1).ExpTaylor(2).String() -// d.String() // output: "216314672147.06" -// -// NewFromFloat(26.1).ExpTaylor(20).String() -// d.String() // output: "216314672147.05767284062928674083" +// d, err := NewFromFloat(26.1).ExpTaylor(2).String() +// d.String() // output: "216314672147.06" // -// 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() { @@ -851,10 +847,9 @@ 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() @@ -905,7 +900,6 @@ 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 +1008,12 @@ 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 +1023,13 @@ 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 +1040,13 @@ 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 +1064,8 @@ 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 +1094,10 @@ 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: "-1.5" func (d Decimal) RoundCeil(places int32) Decimal { if d.exp >= -places { return d @@ -1130,11 +1119,10 @@ 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: "-1.4" func (d Decimal) RoundFloor(places int32) Decimal { if d.exp >= -places { return d @@ -1156,11 +1144,10 @@ 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: "-1.4" func (d Decimal) RoundUp(places int32) Decimal { if d.exp >= -places { return d @@ -1184,11 +1171,10 @@ 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: "-1.5" func (d Decimal) RoundDown(places int32) Decimal { if d.exp >= -places { return d @@ -1209,13 +1195,12 @@ 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 +1222,13 @@ 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 +1297,7 @@ 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 { @@ -1330,7 +1316,10 @@ func (d *Decimal) UnmarshalJSON(decimalBytes []byte) error { if err != nil { return fmt.Errorf("error decoding string '%s': %s", decimalBytes, err) } - + if len(str) == 0 { + *d = Zero + return nil + } decimal, err := NewFromString(str) *d = decimal if err != nil { @@ -1515,7 +1504,7 @@ 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 +1521,7 @@ 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 { @@ -1599,7 +1588,7 @@ func unquoteIfQuoted(value interface{}) (string, error) { } // If the amount is quoted, strip the quotes - if len(bytes) > 2 && bytes[0] == '"' && bytes[len(bytes)-1] == '"' { + if len(bytes) >= 2 && bytes[0] == '"' && bytes[len(bytes)-1] == '"' { bytes = bytes[1 : len(bytes)-1] } return string(bytes), nil diff --git a/decimal_test.go b/decimal_test.go index 2b3a99e1..3557e937 100644 --- a/decimal_test.go +++ b/decimal_test.go @@ -623,12 +623,26 @@ func TestUnmarshalJSONNull(t *testing.T) { } } +func TestUnmarshalJSONEmptyString(t *testing.T) { + var doc struct { + Amount Decimal `json:"amount"` + } + docStr := `{"amount": ""}` + err := json.Unmarshal([]byte(docStr), &doc) + if err != nil { + t.Errorf("error unmarshaling %s: %v", docStr, err) + } else if !doc.Amount.Equal(Zero) { + t.Errorf("expected Zero, got %s (%s, %d)", + doc.Amount.String(), + doc.Amount.value.String(), doc.Amount.exp) + } +} + func TestBadJSON(t *testing.T) { for _, testCase := range []string{ "]o_o[", "{", `{"amount":""`, - `{"amount":""}`, `{"amount":"nope"}`, `0.333`, } { @@ -720,7 +734,6 @@ func TestNullDecimalBadJSON(t *testing.T) { "]o_o[", "{", `{"amount":""`, - `{"amount":""}`, `{"amount":"nope"}`, `{"amount":nope}`, `0.333`,