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-rw-r--r--vendor/golang.org/x/text/internal/number/format.go540
1 files changed, 540 insertions, 0 deletions
diff --git a/vendor/golang.org/x/text/internal/number/format.go b/vendor/golang.org/x/text/internal/number/format.go
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+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package number
+
+import (
+ "strconv"
+ "unicode/utf8"
+
+ "golang.org/x/text/language"
+)
+
+// TODO:
+// - grouping of fractions
+// - allow user-defined superscript notation (such as <sup>4</sup>)
+// - same for non-breaking spaces, like &nbsp;
+
+// A VisibleDigits computes digits, comma placement and trailing zeros as they
+// will be shown to the user.
+type VisibleDigits interface {
+ Digits(buf []byte, t language.Tag, scale int) Digits
+ // TODO: Do we also need to add the verb or pass a format.State?
+}
+
+// Formatting proceeds along the following lines:
+// 0) Compose rounding information from format and context.
+// 1) Convert a number into a Decimal.
+// 2) Sanitize Decimal by adding trailing zeros, removing leading digits, and
+// (non-increment) rounding. The Decimal that results from this is suitable
+// for determining the plural form.
+// 3) Render the Decimal in the localized form.
+
+// Formatter contains all the information needed to render a number.
+type Formatter struct {
+ Pattern
+ Info
+}
+
+func (f *Formatter) init(t language.Tag, index []uint8) {
+ f.Info = InfoFromTag(t)
+ for ; ; t = t.Parent() {
+ if ci, ok := language.CompactIndex(t); ok {
+ f.Pattern = formats[index[ci]]
+ break
+ }
+ }
+}
+
+// InitPattern initializes a Formatter for the given Pattern.
+func (f *Formatter) InitPattern(t language.Tag, pat *Pattern) {
+ f.Info = InfoFromTag(t)
+ f.Pattern = *pat
+}
+
+// InitDecimal initializes a Formatter using the default Pattern for the given
+// language.
+func (f *Formatter) InitDecimal(t language.Tag) {
+ f.init(t, tagToDecimal)
+}
+
+// InitScientific initializes a Formatter using the default Pattern for the
+// given language.
+func (f *Formatter) InitScientific(t language.Tag) {
+ f.init(t, tagToScientific)
+ f.Pattern.MinFractionDigits = 0
+ f.Pattern.MaxFractionDigits = -1
+}
+
+// InitEngineering initializes a Formatter using the default Pattern for the
+// given language.
+func (f *Formatter) InitEngineering(t language.Tag) {
+ f.init(t, tagToScientific)
+ f.Pattern.MinFractionDigits = 0
+ f.Pattern.MaxFractionDigits = -1
+ f.Pattern.MaxIntegerDigits = 3
+ f.Pattern.MinIntegerDigits = 1
+}
+
+// InitPercent initializes a Formatter using the default Pattern for the given
+// language.
+func (f *Formatter) InitPercent(t language.Tag) {
+ f.init(t, tagToPercent)
+}
+
+// InitPerMille initializes a Formatter using the default Pattern for the given
+// language.
+func (f *Formatter) InitPerMille(t language.Tag) {
+ f.init(t, tagToPercent)
+ f.Pattern.DigitShift = 3
+}
+
+func (f *Formatter) Append(dst []byte, x interface{}) []byte {
+ var d Decimal
+ r := f.RoundingContext
+ d.Convert(r, x)
+ return f.Render(dst, FormatDigits(&d, r))
+}
+
+func FormatDigits(d *Decimal, r RoundingContext) Digits {
+ if r.isScientific() {
+ return scientificVisibleDigits(r, d)
+ }
+ return decimalVisibleDigits(r, d)
+}
+
+func (f *Formatter) Format(dst []byte, d *Decimal) []byte {
+ return f.Render(dst, FormatDigits(d, f.RoundingContext))
+}
+
+func (f *Formatter) Render(dst []byte, d Digits) []byte {
+ var result []byte
+ var postPrefix, preSuffix int
+ if d.IsScientific {
+ result, postPrefix, preSuffix = appendScientific(dst, f, &d)
+ } else {
+ result, postPrefix, preSuffix = appendDecimal(dst, f, &d)
+ }
+ if f.PadRune == 0 {
+ return result
+ }
+ width := int(f.FormatWidth)
+ if count := utf8.RuneCount(result); count < width {
+ insertPos := 0
+ switch f.Flags & PadMask {
+ case PadAfterPrefix:
+ insertPos = postPrefix
+ case PadBeforeSuffix:
+ insertPos = preSuffix
+ case PadAfterSuffix:
+ insertPos = len(result)
+ }
+ num := width - count
+ pad := [utf8.UTFMax]byte{' '}
+ sz := 1
+ if r := f.PadRune; r != 0 {
+ sz = utf8.EncodeRune(pad[:], r)
+ }
+ extra := sz * num
+ if n := len(result) + extra; n < cap(result) {
+ result = result[:n]
+ copy(result[insertPos+extra:], result[insertPos:])
+ } else {
+ buf := make([]byte, n)
+ copy(buf, result[:insertPos])
+ copy(buf[insertPos+extra:], result[insertPos:])
+ result = buf
+ }
+ for ; num > 0; num-- {
+ insertPos += copy(result[insertPos:], pad[:sz])
+ }
+ }
+ return result
+}
+
+// decimalVisibleDigits converts d according to the RoundingContext. Note that
+// the exponent may change as a result of this operation.
+func decimalVisibleDigits(r RoundingContext, d *Decimal) Digits {
+ if d.NaN || d.Inf {
+ return Digits{digits: digits{Neg: d.Neg, NaN: d.NaN, Inf: d.Inf}}
+ }
+ n := Digits{digits: d.normalize().digits}
+
+ exp := n.Exp
+ exp += int32(r.DigitShift)
+
+ // Cap integer digits. Remove *most-significant* digits.
+ if r.MaxIntegerDigits > 0 {
+ if p := int(exp) - int(r.MaxIntegerDigits); p > 0 {
+ if p > len(n.Digits) {
+ p = len(n.Digits)
+ }
+ if n.Digits = n.Digits[p:]; len(n.Digits) == 0 {
+ exp = 0
+ } else {
+ exp -= int32(p)
+ }
+ // Strip leading zeros.
+ for len(n.Digits) > 0 && n.Digits[0] == 0 {
+ n.Digits = n.Digits[1:]
+ exp--
+ }
+ }
+ }
+
+ // Rounding if not already done by Convert.
+ p := len(n.Digits)
+ if maxSig := int(r.MaxSignificantDigits); maxSig > 0 {
+ p = maxSig
+ }
+ if maxFrac := int(r.MaxFractionDigits); maxFrac >= 0 {
+ if cap := int(exp) + maxFrac; cap < p {
+ p = int(exp) + maxFrac
+ }
+ if p < 0 {
+ p = 0
+ }
+ }
+ n.round(r.Mode, p)
+
+ // set End (trailing zeros)
+ n.End = int32(len(n.Digits))
+ if n.End == 0 {
+ exp = 0
+ if r.MinFractionDigits > 0 {
+ n.End = int32(r.MinFractionDigits)
+ }
+ if p := int32(r.MinSignificantDigits) - 1; p > n.End {
+ n.End = p
+ }
+ } else {
+ if end := exp + int32(r.MinFractionDigits); end > n.End {
+ n.End = end
+ }
+ if n.End < int32(r.MinSignificantDigits) {
+ n.End = int32(r.MinSignificantDigits)
+ }
+ }
+ n.Exp = exp
+ return n
+}
+
+// appendDecimal appends a formatted number to dst. It returns two possible
+// insertion points for padding.
+func appendDecimal(dst []byte, f *Formatter, n *Digits) (b []byte, postPre, preSuf int) {
+ if dst, ok := f.renderSpecial(dst, n); ok {
+ return dst, 0, len(dst)
+ }
+ digits := n.Digits
+ exp := n.Exp
+
+ // Split in integer and fraction part.
+ var intDigits, fracDigits []byte
+ numInt := 0
+ numFrac := int(n.End - n.Exp)
+ if exp > 0 {
+ numInt = int(exp)
+ if int(exp) >= len(digits) { // ddddd | ddddd00
+ intDigits = digits
+ } else { // ddd.dd
+ intDigits = digits[:exp]
+ fracDigits = digits[exp:]
+ }
+ } else {
+ fracDigits = digits
+ }
+
+ neg := n.Neg
+ affix, suffix := f.getAffixes(neg)
+ dst = appendAffix(dst, f, affix, neg)
+ savedLen := len(dst)
+
+ minInt := int(f.MinIntegerDigits)
+ if minInt == 0 && f.MinSignificantDigits > 0 {
+ minInt = 1
+ }
+ // add leading zeros
+ for i := minInt; i > numInt; i-- {
+ dst = f.AppendDigit(dst, 0)
+ if f.needsSep(i) {
+ dst = append(dst, f.Symbol(SymGroup)...)
+ }
+ }
+ i := 0
+ for ; i < len(intDigits); i++ {
+ dst = f.AppendDigit(dst, intDigits[i])
+ if f.needsSep(numInt - i) {
+ dst = append(dst, f.Symbol(SymGroup)...)
+ }
+ }
+ for ; i < numInt; i++ {
+ dst = f.AppendDigit(dst, 0)
+ if f.needsSep(numInt - i) {
+ dst = append(dst, f.Symbol(SymGroup)...)
+ }
+ }
+
+ if numFrac > 0 || f.Flags&AlwaysDecimalSeparator != 0 {
+ dst = append(dst, f.Symbol(SymDecimal)...)
+ }
+ // Add trailing zeros
+ i = 0
+ for n := -int(n.Exp); i < n; i++ {
+ dst = f.AppendDigit(dst, 0)
+ }
+ for _, d := range fracDigits {
+ i++
+ dst = f.AppendDigit(dst, d)
+ }
+ for ; i < numFrac; i++ {
+ dst = f.AppendDigit(dst, 0)
+ }
+ return appendAffix(dst, f, suffix, neg), savedLen, len(dst)
+}
+
+func scientificVisibleDigits(r RoundingContext, d *Decimal) Digits {
+ if d.NaN || d.Inf {
+ return Digits{digits: digits{Neg: d.Neg, NaN: d.NaN, Inf: d.Inf}}
+ }
+ n := Digits{digits: d.normalize().digits, IsScientific: true}
+
+ // Normalize to have at least one digit. This simplifies engineering
+ // notation.
+ if len(n.Digits) == 0 {
+ n.Digits = append(n.Digits, 0)
+ n.Exp = 1
+ }
+
+ // Significant digits are transformed by the parser for scientific notation
+ // and do not need to be handled here.
+ maxInt, numInt := int(r.MaxIntegerDigits), int(r.MinIntegerDigits)
+ if numInt == 0 {
+ numInt = 1
+ }
+
+ // If a maximum number of integers is specified, the minimum must be 1
+ // and the exponent is grouped by this number (e.g. for engineering)
+ if maxInt > numInt {
+ // Correct the exponent to reflect a single integer digit.
+ numInt = 1
+ // engineering
+ // 0.01234 ([12345]e-1) -> 1.2345e-2 12.345e-3
+ // 12345 ([12345]e+5) -> 1.2345e4 12.345e3
+ d := int(n.Exp-1) % maxInt
+ if d < 0 {
+ d += maxInt
+ }
+ numInt += d
+ }
+
+ p := len(n.Digits)
+ if maxSig := int(r.MaxSignificantDigits); maxSig > 0 {
+ p = maxSig
+ }
+ if maxFrac := int(r.MaxFractionDigits); maxFrac >= 0 && numInt+maxFrac < p {
+ p = numInt + maxFrac
+ }
+ n.round(r.Mode, p)
+
+ n.Comma = uint8(numInt)
+ n.End = int32(len(n.Digits))
+ if minSig := int32(r.MinFractionDigits) + int32(numInt); n.End < minSig {
+ n.End = minSig
+ }
+ return n
+}
+
+// appendScientific appends a formatted number to dst. It returns two possible
+// insertion points for padding.
+func appendScientific(dst []byte, f *Formatter, n *Digits) (b []byte, postPre, preSuf int) {
+ if dst, ok := f.renderSpecial(dst, n); ok {
+ return dst, 0, 0
+ }
+ digits := n.Digits
+ numInt := int(n.Comma)
+ numFrac := int(n.End) - int(n.Comma)
+
+ var intDigits, fracDigits []byte
+ if numInt <= len(digits) {
+ intDigits = digits[:numInt]
+ fracDigits = digits[numInt:]
+ } else {
+ intDigits = digits
+ }
+ neg := n.Neg
+ affix, suffix := f.getAffixes(neg)
+ dst = appendAffix(dst, f, affix, neg)
+ savedLen := len(dst)
+
+ i := 0
+ for ; i < len(intDigits); i++ {
+ dst = f.AppendDigit(dst, intDigits[i])
+ if f.needsSep(numInt - i) {
+ dst = append(dst, f.Symbol(SymGroup)...)
+ }
+ }
+ for ; i < numInt; i++ {
+ dst = f.AppendDigit(dst, 0)
+ if f.needsSep(numInt - i) {
+ dst = append(dst, f.Symbol(SymGroup)...)
+ }
+ }
+
+ if numFrac > 0 || f.Flags&AlwaysDecimalSeparator != 0 {
+ dst = append(dst, f.Symbol(SymDecimal)...)
+ }
+ i = 0
+ for ; i < len(fracDigits); i++ {
+ dst = f.AppendDigit(dst, fracDigits[i])
+ }
+ for ; i < numFrac; i++ {
+ dst = f.AppendDigit(dst, 0)
+ }
+
+ // exp
+ buf := [12]byte{}
+ // TODO: use exponential if superscripting is not available (no Latin
+ // numbers or no tags) and use exponential in all other cases.
+ exp := n.Exp - int32(n.Comma)
+ exponential := f.Symbol(SymExponential)
+ if exponential == "E" {
+ dst = append(dst, "\u202f"...) // NARROW NO-BREAK SPACE
+ dst = append(dst, f.Symbol(SymSuperscriptingExponent)...)
+ dst = append(dst, "\u202f"...) // NARROW NO-BREAK SPACE
+ dst = f.AppendDigit(dst, 1)
+ dst = f.AppendDigit(dst, 0)
+ switch {
+ case exp < 0:
+ dst = append(dst, superMinus...)
+ exp = -exp
+ case f.Flags&AlwaysExpSign != 0:
+ dst = append(dst, superPlus...)
+ }
+ b = strconv.AppendUint(buf[:0], uint64(exp), 10)
+ for i := len(b); i < int(f.MinExponentDigits); i++ {
+ dst = append(dst, superDigits[0]...)
+ }
+ for _, c := range b {
+ dst = append(dst, superDigits[c-'0']...)
+ }
+ } else {
+ dst = append(dst, exponential...)
+ switch {
+ case exp < 0:
+ dst = append(dst, f.Symbol(SymMinusSign)...)
+ exp = -exp
+ case f.Flags&AlwaysExpSign != 0:
+ dst = append(dst, f.Symbol(SymPlusSign)...)
+ }
+ b = strconv.AppendUint(buf[:0], uint64(exp), 10)
+ for i := len(b); i < int(f.MinExponentDigits); i++ {
+ dst = f.AppendDigit(dst, 0)
+ }
+ for _, c := range b {
+ dst = f.AppendDigit(dst, c-'0')
+ }
+ }
+ return appendAffix(dst, f, suffix, neg), savedLen, len(dst)
+}
+
+const (
+ superMinus = "\u207B" // SUPERSCRIPT HYPHEN-MINUS
+ superPlus = "\u207A" // SUPERSCRIPT PLUS SIGN
+)
+
+var (
+ // Note: the digits are not sequential!!!
+ superDigits = []string{
+ "\u2070", // SUPERSCRIPT DIGIT ZERO
+ "\u00B9", // SUPERSCRIPT DIGIT ONE
+ "\u00B2", // SUPERSCRIPT DIGIT TWO
+ "\u00B3", // SUPERSCRIPT DIGIT THREE
+ "\u2074", // SUPERSCRIPT DIGIT FOUR
+ "\u2075", // SUPERSCRIPT DIGIT FIVE
+ "\u2076", // SUPERSCRIPT DIGIT SIX
+ "\u2077", // SUPERSCRIPT DIGIT SEVEN
+ "\u2078", // SUPERSCRIPT DIGIT EIGHT
+ "\u2079", // SUPERSCRIPT DIGIT NINE
+ }
+)
+
+func (f *Formatter) getAffixes(neg bool) (affix, suffix string) {
+ str := f.Affix
+ if str != "" {
+ if f.NegOffset > 0 {
+ if neg {
+ str = str[f.NegOffset:]
+ } else {
+ str = str[:f.NegOffset]
+ }
+ }
+ sufStart := 1 + str[0]
+ affix = str[1:sufStart]
+ suffix = str[sufStart+1:]
+ }
+ // TODO: introduce a NeedNeg sign to indicate if the left pattern already
+ // has a sign marked?
+ if f.NegOffset == 0 && (neg || f.Flags&AlwaysSign != 0) {
+ affix = "-" + affix
+ }
+ return affix, suffix
+}
+
+func (f *Formatter) renderSpecial(dst []byte, d *Digits) (b []byte, ok bool) {
+ if d.NaN {
+ return fmtNaN(dst, f), true
+ }
+ if d.Inf {
+ return fmtInfinite(dst, f, d), true
+ }
+ return dst, false
+}
+
+func fmtNaN(dst []byte, f *Formatter) []byte {
+ return append(dst, f.Symbol(SymNan)...)
+}
+
+func fmtInfinite(dst []byte, f *Formatter, d *Digits) []byte {
+ affix, suffix := f.getAffixes(d.Neg)
+ dst = appendAffix(dst, f, affix, d.Neg)
+ dst = append(dst, f.Symbol(SymInfinity)...)
+ dst = appendAffix(dst, f, suffix, d.Neg)
+ return dst
+}
+
+func appendAffix(dst []byte, f *Formatter, affix string, neg bool) []byte {
+ quoting := false
+ escaping := false
+ for _, r := range affix {
+ switch {
+ case escaping:
+ // escaping occurs both inside and outside of quotes
+ dst = append(dst, string(r)...)
+ escaping = false
+ case r == '\\':
+ escaping = true
+ case r == '\'':
+ quoting = !quoting
+ case quoting:
+ dst = append(dst, string(r)...)
+ case r == '%':
+ if f.DigitShift == 3 {
+ dst = append(dst, f.Symbol(SymPerMille)...)
+ } else {
+ dst = append(dst, f.Symbol(SymPercentSign)...)
+ }
+ case r == '-' || r == '+':
+ if neg {
+ dst = append(dst, f.Symbol(SymMinusSign)...)
+ } else if f.Flags&ElideSign == 0 {
+ dst = append(dst, f.Symbol(SymPlusSign)...)
+ } else {
+ dst = append(dst, ' ')
+ }
+ default:
+ dst = append(dst, string(r)...)
+ }
+ }
+ return dst
+}