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Diffstat (limited to 'vendor/github.com/dustin/go-humanize/number.go')
| -rw-r--r-- | vendor/github.com/dustin/go-humanize/number.go | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/vendor/github.com/dustin/go-humanize/number.go b/vendor/github.com/dustin/go-humanize/number.go new file mode 100644 index 000000000..dec618659 --- /dev/null +++ b/vendor/github.com/dustin/go-humanize/number.go @@ -0,0 +1,192 @@ +package humanize + +/* +Slightly adapted from the source to fit go-humanize. + +Author: https://github.com/gorhill +Source: https://gist.github.com/gorhill/5285193 + +*/ + +import ( + "math" + "strconv" +) + +var ( + renderFloatPrecisionMultipliers = [...]float64{ + 1, + 10, + 100, + 1000, + 10000, + 100000, + 1000000, + 10000000, + 100000000, + 1000000000, + } + + renderFloatPrecisionRounders = [...]float64{ + 0.5, + 0.05, + 0.005, + 0.0005, + 0.00005, + 0.000005, + 0.0000005, + 0.00000005, + 0.000000005, + 0.0000000005, + } +) + +// FormatFloat produces a formatted number as string based on the following user-specified criteria: +// * thousands separator +// * decimal separator +// * decimal precision +// +// Usage: s := RenderFloat(format, n) +// The format parameter tells how to render the number n. +// +// See examples: http://play.golang.org/p/LXc1Ddm1lJ +// +// Examples of format strings, given n = 12345.6789: +// "#,###.##" => "12,345.67" +// "#,###." => "12,345" +// "#,###" => "12345,678" +// "#\u202F###,##" => "12 345,68" +// "#.###,###### => 12.345,678900 +// "" (aka default format) => 12,345.67 +// +// The highest precision allowed is 9 digits after the decimal symbol. +// There is also a version for integer number, FormatInteger(), +// which is convenient for calls within template. +func FormatFloat(format string, n float64) string { + // Special cases: + // NaN = "NaN" + // +Inf = "+Infinity" + // -Inf = "-Infinity" + if math.IsNaN(n) { + return "NaN" + } + if n > math.MaxFloat64 { + return "Infinity" + } + if n < -math.MaxFloat64 { + return "-Infinity" + } + + // default format + precision := 2 + decimalStr := "." + thousandStr := "," + positiveStr := "" + negativeStr := "-" + + if len(format) > 0 { + format := []rune(format) + + // If there is an explicit format directive, + // then default values are these: + precision = 9 + thousandStr = "" + + // collect indices of meaningful formatting directives + formatIndx := []int{} + for i, char := range format { + if char != '#' && char != '0' { + formatIndx = append(formatIndx, i) + } + } + + if len(formatIndx) > 0 { + // Directive at index 0: + // Must be a '+' + // Raise an error if not the case + // index: 0123456789 + // +0.000,000 + // +000,000.0 + // +0000.00 + // +0000 + if formatIndx[0] == 0 { + if format[formatIndx[0]] != '+' { + panic("RenderFloat(): invalid positive sign directive") + } + positiveStr = "+" + formatIndx = formatIndx[1:] + } + + // Two directives: + // First is thousands separator + // Raise an error if not followed by 3-digit + // 0123456789 + // 0.000,000 + // 000,000.00 + if len(formatIndx) == 2 { + if (formatIndx[1] - formatIndx[0]) != 4 { + panic("RenderFloat(): thousands separator directive must be followed by 3 digit-specifiers") + } + thousandStr = string(format[formatIndx[0]]) + formatIndx = formatIndx[1:] + } + + // One directive: + // Directive is decimal separator + // The number of digit-specifier following the separator indicates wanted precision + // 0123456789 + // 0.00 + // 000,0000 + if len(formatIndx) == 1 { + decimalStr = string(format[formatIndx[0]]) + precision = len(format) - formatIndx[0] - 1 + } + } + } + + // generate sign part + var signStr string + if n >= 0.000000001 { + signStr = positiveStr + } else if n <= -0.000000001 { + signStr = negativeStr + n = -n + } else { + signStr = "" + n = 0.0 + } + + // split number into integer and fractional parts + intf, fracf := math.Modf(n + renderFloatPrecisionRounders[precision]) + + // generate integer part string + intStr := strconv.FormatInt(int64(intf), 10) + + // add thousand separator if required + if len(thousandStr) > 0 { + for i := len(intStr); i > 3; { + i -= 3 + intStr = intStr[:i] + thousandStr + intStr[i:] + } + } + + // no fractional part, we can leave now + if precision == 0 { + return signStr + intStr + } + + // generate fractional part + fracStr := strconv.Itoa(int(fracf * renderFloatPrecisionMultipliers[precision])) + // may need padding + if len(fracStr) < precision { + fracStr = "000000000000000"[:precision-len(fracStr)] + fracStr + } + + return signStr + intStr + decimalStr + fracStr +} + +// FormatInteger produces a formatted number as string. +// See FormatFloat. +func FormatInteger(format string, n int) string { + return FormatFloat(format, float64(n)) +} |