From 621e49bb465f500cc46d47e39e828cf76d6381d7 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Tue, 24 Jul 2018 14:35:44 +0200 Subject: update vendor --- .../golang.org/x/text/internal/number/pattern.go | 485 +++++++++++++++++++++ 1 file changed, 485 insertions(+) create mode 100644 vendor/golang.org/x/text/internal/number/pattern.go (limited to 'vendor/golang.org/x/text/internal/number/pattern.go') diff --git a/vendor/golang.org/x/text/internal/number/pattern.go b/vendor/golang.org/x/text/internal/number/pattern.go new file mode 100644 index 0000000..b95ca40 --- /dev/null +++ b/vendor/golang.org/x/text/internal/number/pattern.go @@ -0,0 +1,485 @@ +// Copyright 2015 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 ( + "errors" + "unicode/utf8" +) + +// This file contains a parser for the CLDR number patterns as described in +// http://unicode.org/reports/tr35/tr35-numbers.html#Number_Format_Patterns. +// +// The following BNF is derived from this standard. +// +// pattern := subpattern (';' subpattern)? +// subpattern := affix? number exponent? affix? +// number := decimal | sigDigits +// decimal := '#'* '0'* ('.' fraction)? | '#' | '0' +// fraction := '0'* '#'* +// sigDigits := '#'* '@' '@'* '#'* +// exponent := 'E' '+'? '0'* '0' +// padSpec := '*' \L +// +// Notes: +// - An affix pattern may contain any runes, but runes with special meaning +// should be escaped. +// - Sequences of digits, '#', and '@' in decimal and sigDigits may have +// interstitial commas. + +// TODO: replace special characters in affixes (-, +, ¤) with control codes. + +// Pattern holds information for formatting numbers. It is designed to hold +// information from CLDR number patterns. +// +// This pattern is precompiled for all patterns for all languages. Even though +// the number of patterns is not very large, we want to keep this small. +// +// This type is only intended for internal use. +type Pattern struct { + RoundingContext + + Affix string // includes prefix and suffix. First byte is prefix length. + Offset uint16 // Offset into Affix for prefix and suffix + NegOffset uint16 // Offset into Affix for negative prefix and suffix or 0. + PadRune rune + FormatWidth uint16 + + GroupingSize [2]uint8 + Flags PatternFlag +} + +// A RoundingContext indicates how a number should be converted to digits. +// It contains all information needed to determine the "visible digits" as +// required by the pluralization rules. +type RoundingContext struct { + // TODO: unify these two fields so that there is a more unambiguous meaning + // of how precision is handled. + MaxSignificantDigits int16 // -1 is unlimited + MaxFractionDigits int16 // -1 is unlimited + + Increment uint32 + IncrementScale uint8 // May differ from printed scale. + + Mode RoundingMode + + DigitShift uint8 // Number of decimals to shift. Used for % and ‰. + + // Number of digits. + MinIntegerDigits uint8 + + MaxIntegerDigits uint8 + MinFractionDigits uint8 + MinSignificantDigits uint8 + + MinExponentDigits uint8 +} + +// RoundSignificantDigits returns the number of significant digits an +// implementation of Convert may round to or n < 0 if there is no maximum or +// a maximum is not recommended. +func (r *RoundingContext) RoundSignificantDigits() (n int) { + if r.MaxFractionDigits == 0 && r.MaxSignificantDigits > 0 { + return int(r.MaxSignificantDigits) + } else if r.isScientific() && r.MaxIntegerDigits == 1 { + if r.MaxSignificantDigits == 0 || + int(r.MaxFractionDigits+1) == int(r.MaxSignificantDigits) { + // Note: don't add DigitShift: it is only used for decimals. + return int(r.MaxFractionDigits) + 1 + } + } + return -1 +} + +// RoundFractionDigits returns the number of fraction digits an implementation +// of Convert may round to or n < 0 if there is no maximum or a maximum is not +// recommended. +func (r *RoundingContext) RoundFractionDigits() (n int) { + if r.MinExponentDigits == 0 && + r.MaxSignificantDigits == 0 && + r.MaxFractionDigits >= 0 { + return int(r.MaxFractionDigits) + int(r.DigitShift) + } + return -1 +} + +// SetScale fixes the RoundingContext to a fixed number of fraction digits. +func (r *RoundingContext) SetScale(scale int) { + r.MinFractionDigits = uint8(scale) + r.MaxFractionDigits = int16(scale) +} + +func (r *RoundingContext) SetPrecision(prec int) { + r.MaxSignificantDigits = int16(prec) +} + +func (r *RoundingContext) isScientific() bool { + return r.MinExponentDigits > 0 +} + +func (f *Pattern) needsSep(pos int) bool { + p := pos - 1 + size := int(f.GroupingSize[0]) + if size == 0 || p == 0 { + return false + } + if p == size { + return true + } + if p -= size; p < 0 { + return false + } + // TODO: make second groupingsize the same as first if 0 so that we can + // avoid this check. + if x := int(f.GroupingSize[1]); x != 0 { + size = x + } + return p%size == 0 +} + +// A PatternFlag is a bit mask for the flag field of a Pattern. +type PatternFlag uint8 + +const ( + AlwaysSign PatternFlag = 1 << iota + ElideSign // Use space instead of plus sign. AlwaysSign must be true. + AlwaysExpSign + AlwaysDecimalSeparator + ParenthesisForNegative // Common pattern. Saves space. + + PadAfterNumber + PadAfterAffix + + PadBeforePrefix = 0 // Default + PadAfterPrefix = PadAfterAffix + PadBeforeSuffix = PadAfterNumber + PadAfterSuffix = PadAfterNumber | PadAfterAffix + PadMask = PadAfterNumber | PadAfterAffix +) + +type parser struct { + *Pattern + + leadingSharps int + + pos int + err error + doNotTerminate bool + groupingCount uint + hasGroup bool + buf []byte +} + +func (p *parser) setError(err error) { + if p.err == nil { + p.err = err + } +} + +func (p *parser) updateGrouping() { + if p.hasGroup && + 0 < p.groupingCount && p.groupingCount < 255 { + p.GroupingSize[1] = p.GroupingSize[0] + p.GroupingSize[0] = uint8(p.groupingCount) + } + p.groupingCount = 0 + p.hasGroup = true +} + +var ( + // TODO: more sensible and localizeable error messages. + errMultiplePadSpecifiers = errors.New("format: pattern has multiple pad specifiers") + errInvalidPadSpecifier = errors.New("format: invalid pad specifier") + errInvalidQuote = errors.New("format: invalid quote") + errAffixTooLarge = errors.New("format: prefix or suffix exceeds maximum UTF-8 length of 256 bytes") + errDuplicatePercentSign = errors.New("format: duplicate percent sign") + errDuplicatePermilleSign = errors.New("format: duplicate permille sign") + errUnexpectedEnd = errors.New("format: unexpected end of pattern") +) + +// ParsePattern extracts formatting information from a CLDR number pattern. +// +// See http://unicode.org/reports/tr35/tr35-numbers.html#Number_Format_Patterns. +func ParsePattern(s string) (f *Pattern, err error) { + p := parser{Pattern: &Pattern{}} + + s = p.parseSubPattern(s) + + if s != "" { + // Parse negative sub pattern. + if s[0] != ';' { + p.setError(errors.New("format: error parsing first sub pattern")) + return nil, p.err + } + neg := parser{Pattern: &Pattern{}} // just for extracting the affixes. + s = neg.parseSubPattern(s[len(";"):]) + p.NegOffset = uint16(len(p.buf)) + p.buf = append(p.buf, neg.buf...) + } + if s != "" { + p.setError(errors.New("format: spurious characters at end of pattern")) + } + if p.err != nil { + return nil, p.err + } + if affix := string(p.buf); affix == "\x00\x00" || affix == "\x00\x00\x00\x00" { + // No prefix or suffixes. + p.NegOffset = 0 + } else { + p.Affix = affix + } + if p.Increment == 0 { + p.IncrementScale = 0 + } + return p.Pattern, nil +} + +func (p *parser) parseSubPattern(s string) string { + s = p.parsePad(s, PadBeforePrefix) + s = p.parseAffix(s) + s = p.parsePad(s, PadAfterPrefix) + + s = p.parse(p.number, s) + p.updateGrouping() + + s = p.parsePad(s, PadBeforeSuffix) + s = p.parseAffix(s) + s = p.parsePad(s, PadAfterSuffix) + return s +} + +func (p *parser) parsePad(s string, f PatternFlag) (tail string) { + if len(s) >= 2 && s[0] == '*' { + r, sz := utf8.DecodeRuneInString(s[1:]) + if p.PadRune != 0 { + p.err = errMultiplePadSpecifiers + } else { + p.Flags |= f + p.PadRune = r + } + return s[1+sz:] + } + return s +} + +func (p *parser) parseAffix(s string) string { + x := len(p.buf) + p.buf = append(p.buf, 0) // placeholder for affix length + + s = p.parse(p.affix, s) + + n := len(p.buf) - x - 1 + if n > 0xFF { + p.setError(errAffixTooLarge) + } + p.buf[x] = uint8(n) + return s +} + +// state implements a state transition. It returns the new state. A state +// function may set an error on the parser or may simply return on an incorrect +// token and let the next phase fail. +type state func(r rune) state + +// parse repeatedly applies a state function on the given string until a +// termination condition is reached. +func (p *parser) parse(fn state, s string) (tail string) { + for i, r := range s { + p.doNotTerminate = false + if fn = fn(r); fn == nil || p.err != nil { + return s[i:] + } + p.FormatWidth++ + } + if p.doNotTerminate { + p.setError(errUnexpectedEnd) + } + return "" +} + +func (p *parser) affix(r rune) state { + switch r { + case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', + '#', '@', '.', '*', ',', ';': + return nil + case '\'': + p.FormatWidth-- + return p.escapeFirst + case '%': + if p.DigitShift != 0 { + p.setError(errDuplicatePercentSign) + } + p.DigitShift = 2 + case '\u2030': // ‰ Per mille + if p.DigitShift != 0 { + p.setError(errDuplicatePermilleSign) + } + p.DigitShift = 3 + // TODO: handle currency somehow: ¤, ¤¤, ¤¤¤, ¤¤¤¤ + } + p.buf = append(p.buf, string(r)...) + return p.affix +} + +func (p *parser) escapeFirst(r rune) state { + switch r { + case '\'': + p.buf = append(p.buf, "\\'"...) + return p.affix + default: + p.buf = append(p.buf, '\'') + p.buf = append(p.buf, string(r)...) + } + return p.escape +} + +func (p *parser) escape(r rune) state { + switch r { + case '\'': + p.FormatWidth-- + p.buf = append(p.buf, '\'') + return p.affix + default: + p.buf = append(p.buf, string(r)...) + } + return p.escape +} + +// number parses a number. The BNF says the integer part should always have +// a '0', but that does not appear to be the case according to the rest of the +// documentation. We will allow having only '#' numbers. +func (p *parser) number(r rune) state { + switch r { + case '#': + p.groupingCount++ + p.leadingSharps++ + case '@': + p.groupingCount++ + p.leadingSharps = 0 + p.MaxFractionDigits = -1 + return p.sigDigits(r) + case ',': + if p.leadingSharps == 0 { // no leading commas + return nil + } + p.updateGrouping() + case 'E': + p.MaxIntegerDigits = uint8(p.leadingSharps) + return p.exponent + case '.': // allow ".##" etc. + p.updateGrouping() + return p.fraction + case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9': + return p.integer(r) + default: + return nil + } + return p.number +} + +func (p *parser) integer(r rune) state { + if !('0' <= r && r <= '9') { + var next state + switch r { + case 'E': + if p.leadingSharps > 0 { + p.MaxIntegerDigits = uint8(p.leadingSharps) + p.MinIntegerDigits + } + next = p.exponent + case '.': + next = p.fraction + case ',': + next = p.integer + } + p.updateGrouping() + return next + } + p.Increment = p.Increment*10 + uint32(r-'0') + p.groupingCount++ + p.MinIntegerDigits++ + return p.integer +} + +func (p *parser) sigDigits(r rune) state { + switch r { + case '@': + p.groupingCount++ + p.MaxSignificantDigits++ + p.MinSignificantDigits++ + case '#': + return p.sigDigitsFinal(r) + case 'E': + p.updateGrouping() + return p.normalizeSigDigitsWithExponent() + default: + p.updateGrouping() + return nil + } + return p.sigDigits +} + +func (p *parser) sigDigitsFinal(r rune) state { + switch r { + case '#': + p.groupingCount++ + p.MaxSignificantDigits++ + case 'E': + p.updateGrouping() + return p.normalizeSigDigitsWithExponent() + default: + p.updateGrouping() + return nil + } + return p.sigDigitsFinal +} + +func (p *parser) normalizeSigDigitsWithExponent() state { + p.MinIntegerDigits, p.MaxIntegerDigits = 1, 1 + p.MinFractionDigits = p.MinSignificantDigits - 1 + p.MaxFractionDigits = p.MaxSignificantDigits - 1 + p.MinSignificantDigits, p.MaxSignificantDigits = 0, 0 + return p.exponent +} + +func (p *parser) fraction(r rune) state { + switch r { + case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9': + p.Increment = p.Increment*10 + uint32(r-'0') + p.IncrementScale++ + p.MinFractionDigits++ + p.MaxFractionDigits++ + case '#': + p.MaxFractionDigits++ + case 'E': + if p.leadingSharps > 0 { + p.MaxIntegerDigits = uint8(p.leadingSharps) + p.MinIntegerDigits + } + return p.exponent + default: + return nil + } + return p.fraction +} + +func (p *parser) exponent(r rune) state { + switch r { + case '+': + // Set mode and check it wasn't already set. + if p.Flags&AlwaysExpSign != 0 || p.MinExponentDigits > 0 { + break + } + p.Flags |= AlwaysExpSign + p.doNotTerminate = true + return p.exponent + case '0': + p.MinExponentDigits++ + return p.exponent + } + // termination condition + if p.MinExponentDigits == 0 { + p.setError(errors.New("format: need at least one digit")) + } + return nil +} -- cgit v1.2.3