From 2f0b35e3c25bc4394f3288e1baa77d250cb510ed Mon Sep 17 00:00:00 2001 From: Jordan Date: Thu, 10 Feb 2022 19:10:54 -0700 Subject: misc: go mod vendor --- vendor/golang.org/x/text/unicode/bidi/bidi.go | 359 ++++++++++++++++++++++++++ 1 file changed, 359 insertions(+) create mode 100644 vendor/golang.org/x/text/unicode/bidi/bidi.go (limited to 'vendor/golang.org/x/text/unicode/bidi/bidi.go') diff --git a/vendor/golang.org/x/text/unicode/bidi/bidi.go b/vendor/golang.org/x/text/unicode/bidi/bidi.go new file mode 100644 index 0000000..fd05760 --- /dev/null +++ b/vendor/golang.org/x/text/unicode/bidi/bidi.go @@ -0,0 +1,359 @@ +// 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. + +//go:generate go run gen.go gen_trieval.go gen_ranges.go + +// Package bidi contains functionality for bidirectional text support. +// +// See https://www.unicode.org/reports/tr9. +// +// NOTE: UNDER CONSTRUCTION. This API may change in backwards incompatible ways +// and without notice. +package bidi // import "golang.org/x/text/unicode/bidi" + +// TODO +// - Transformer for reordering? +// - Transformer (validator, really) for Bidi Rule. + +import ( + "bytes" +) + +// This API tries to avoid dealing with embedding levels for now. Under the hood +// these will be computed, but the question is to which extent the user should +// know they exist. We should at some point allow the user to specify an +// embedding hierarchy, though. + +// A Direction indicates the overall flow of text. +type Direction int + +const ( + // LeftToRight indicates the text contains no right-to-left characters and + // that either there are some left-to-right characters or the option + // DefaultDirection(LeftToRight) was passed. + LeftToRight Direction = iota + + // RightToLeft indicates the text contains no left-to-right characters and + // that either there are some right-to-left characters or the option + // DefaultDirection(RightToLeft) was passed. + RightToLeft + + // Mixed indicates text contains both left-to-right and right-to-left + // characters. + Mixed + + // Neutral means that text contains no left-to-right and right-to-left + // characters and that no default direction has been set. + Neutral +) + +type options struct { + defaultDirection Direction +} + +// An Option is an option for Bidi processing. +type Option func(*options) + +// ICU allows the user to define embedding levels. This may be used, for example, +// to use hierarchical structure of markup languages to define embeddings. +// The following option may be a way to expose this functionality in this API. +// // LevelFunc sets a function that associates nesting levels with the given text. +// // The levels function will be called with monotonically increasing values for p. +// func LevelFunc(levels func(p int) int) Option { +// panic("unimplemented") +// } + +// DefaultDirection sets the default direction for a Paragraph. The direction is +// overridden if the text contains directional characters. +func DefaultDirection(d Direction) Option { + return func(opts *options) { + opts.defaultDirection = d + } +} + +// A Paragraph holds a single Paragraph for Bidi processing. +type Paragraph struct { + p []byte + o Ordering + opts []Option + types []Class + pairTypes []bracketType + pairValues []rune + runes []rune + options options +} + +// Initialize the p.pairTypes, p.pairValues and p.types from the input previously +// set by p.SetBytes() or p.SetString(). Also limit the input up to (and including) a paragraph +// separator (bidi class B). +// +// The function p.Order() needs these values to be set, so this preparation could be postponed. +// But since the SetBytes and SetStrings functions return the length of the input up to the paragraph +// separator, the whole input needs to be processed anyway and should not be done twice. +// +// The function has the same return values as SetBytes() / SetString() +func (p *Paragraph) prepareInput() (n int, err error) { + p.runes = bytes.Runes(p.p) + bytecount := 0 + // clear slices from previous SetString or SetBytes + p.pairTypes = nil + p.pairValues = nil + p.types = nil + + for _, r := range p.runes { + props, i := LookupRune(r) + bytecount += i + cls := props.Class() + if cls == B { + return bytecount, nil + } + p.types = append(p.types, cls) + if props.IsOpeningBracket() { + p.pairTypes = append(p.pairTypes, bpOpen) + p.pairValues = append(p.pairValues, r) + } else if props.IsBracket() { + // this must be a closing bracket, + // since IsOpeningBracket is not true + p.pairTypes = append(p.pairTypes, bpClose) + p.pairValues = append(p.pairValues, r) + } else { + p.pairTypes = append(p.pairTypes, bpNone) + p.pairValues = append(p.pairValues, 0) + } + } + return bytecount, nil +} + +// SetBytes configures p for the given paragraph text. It replaces text +// previously set by SetBytes or SetString. If b contains a paragraph separator +// it will only process the first paragraph and report the number of bytes +// consumed from b including this separator. Error may be non-nil if options are +// given. +func (p *Paragraph) SetBytes(b []byte, opts ...Option) (n int, err error) { + p.p = b + p.opts = opts + return p.prepareInput() +} + +// SetString configures s for the given paragraph text. It replaces text +// previously set by SetBytes or SetString. If s contains a paragraph separator +// it will only process the first paragraph and report the number of bytes +// consumed from s including this separator. Error may be non-nil if options are +// given. +func (p *Paragraph) SetString(s string, opts ...Option) (n int, err error) { + p.p = []byte(s) + p.opts = opts + return p.prepareInput() +} + +// IsLeftToRight reports whether the principle direction of rendering for this +// paragraphs is left-to-right. If this returns false, the principle direction +// of rendering is right-to-left. +func (p *Paragraph) IsLeftToRight() bool { + return p.Direction() == LeftToRight +} + +// Direction returns the direction of the text of this paragraph. +// +// The direction may be LeftToRight, RightToLeft, Mixed, or Neutral. +func (p *Paragraph) Direction() Direction { + return p.o.Direction() +} + +// TODO: what happens if the position is > len(input)? This should return an error. + +// RunAt reports the Run at the given position of the input text. +// +// This method can be used for computing line breaks on paragraphs. +func (p *Paragraph) RunAt(pos int) Run { + c := 0 + runNumber := 0 + for i, r := range p.o.runes { + c += len(r) + if pos < c { + runNumber = i + } + } + return p.o.Run(runNumber) +} + +func calculateOrdering(levels []level, runes []rune) Ordering { + var curDir Direction + + prevDir := Neutral + prevI := 0 + + o := Ordering{} + // lvl = 0,2,4,...: left to right + // lvl = 1,3,5,...: right to left + for i, lvl := range levels { + if lvl%2 == 0 { + curDir = LeftToRight + } else { + curDir = RightToLeft + } + if curDir != prevDir { + if i > 0 { + o.runes = append(o.runes, runes[prevI:i]) + o.directions = append(o.directions, prevDir) + o.startpos = append(o.startpos, prevI) + } + prevI = i + prevDir = curDir + } + } + o.runes = append(o.runes, runes[prevI:]) + o.directions = append(o.directions, prevDir) + o.startpos = append(o.startpos, prevI) + return o +} + +// Order computes the visual ordering of all the runs in a Paragraph. +func (p *Paragraph) Order() (Ordering, error) { + if len(p.types) == 0 { + return Ordering{}, nil + } + + for _, fn := range p.opts { + fn(&p.options) + } + lvl := level(-1) + if p.options.defaultDirection == RightToLeft { + lvl = 1 + } + para, err := newParagraph(p.types, p.pairTypes, p.pairValues, lvl) + if err != nil { + return Ordering{}, err + } + + levels := para.getLevels([]int{len(p.types)}) + + p.o = calculateOrdering(levels, p.runes) + return p.o, nil +} + +// Line computes the visual ordering of runs for a single line starting and +// ending at the given positions in the original text. +func (p *Paragraph) Line(start, end int) (Ordering, error) { + lineTypes := p.types[start:end] + para, err := newParagraph(lineTypes, p.pairTypes[start:end], p.pairValues[start:end], -1) + if err != nil { + return Ordering{}, err + } + levels := para.getLevels([]int{len(lineTypes)}) + o := calculateOrdering(levels, p.runes[start:end]) + return o, nil +} + +// An Ordering holds the computed visual order of runs of a Paragraph. Calling +// SetBytes or SetString on the originating Paragraph invalidates an Ordering. +// The methods of an Ordering should only be called by one goroutine at a time. +type Ordering struct { + runes [][]rune + directions []Direction + startpos []int +} + +// Direction reports the directionality of the runs. +// +// The direction may be LeftToRight, RightToLeft, Mixed, or Neutral. +func (o *Ordering) Direction() Direction { + return o.directions[0] +} + +// NumRuns returns the number of runs. +func (o *Ordering) NumRuns() int { + return len(o.runes) +} + +// Run returns the ith run within the ordering. +func (o *Ordering) Run(i int) Run { + r := Run{ + runes: o.runes[i], + direction: o.directions[i], + startpos: o.startpos[i], + } + return r +} + +// TODO: perhaps with options. +// // Reorder creates a reader that reads the runes in visual order per character. +// // Modifiers remain after the runes they modify. +// func (l *Runs) Reorder() io.Reader { +// panic("unimplemented") +// } + +// A Run is a continuous sequence of characters of a single direction. +type Run struct { + runes []rune + direction Direction + startpos int +} + +// String returns the text of the run in its original order. +func (r *Run) String() string { + return string(r.runes) +} + +// Bytes returns the text of the run in its original order. +func (r *Run) Bytes() []byte { + return []byte(r.String()) +} + +// TODO: methods for +// - Display order +// - headers and footers +// - bracket replacement. + +// Direction reports the direction of the run. +func (r *Run) Direction() Direction { + return r.direction +} + +// Pos returns the position of the Run within the text passed to SetBytes or SetString of the +// originating Paragraph value. +func (r *Run) Pos() (start, end int) { + return r.startpos, r.startpos + len(r.runes) - 1 +} + +// AppendReverse reverses the order of characters of in, appends them to out, +// and returns the result. Modifiers will still follow the runes they modify. +// Brackets are replaced with their counterparts. +func AppendReverse(out, in []byte) []byte { + ret := make([]byte, len(in)+len(out)) + copy(ret, out) + inRunes := bytes.Runes(in) + + for i, r := range inRunes { + prop, _ := LookupRune(r) + if prop.IsBracket() { + inRunes[i] = prop.reverseBracket(r) + } + } + + for i, j := 0, len(inRunes)-1; i < j; i, j = i+1, j-1 { + inRunes[i], inRunes[j] = inRunes[j], inRunes[i] + } + copy(ret[len(out):], string(inRunes)) + + return ret +} + +// ReverseString reverses the order of characters in s and returns a new string. +// Modifiers will still follow the runes they modify. Brackets are replaced with +// their counterparts. +func ReverseString(s string) string { + input := []rune(s) + li := len(input) + ret := make([]rune, li) + for i, r := range input { + prop, _ := LookupRune(r) + if prop.IsBracket() { + ret[li-i-1] = prop.reverseBracket(r) + } else { + ret[li-i-1] = r + } + } + return string(ret) +} -- cgit v1.2.3-54-g00ecf