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authorGibheer <gibheer+git@zero-knowledge.org>2024-09-05 19:38:25 +0200
committerGibheer <gibheer+git@zero-knowledge.org>2024-09-05 19:38:25 +0200
commit6ea4d2c82de80efc87708e5e182034b7c6c2019e (patch)
tree35c0856a929040216c82153ca62d43b27530a887 /vendor/golang.org/x/text/unicode/bidi/bidi.go
parent6f64eeace1b66639b9380b44e88a8d54850a4306 (diff)
switch from github.com/lib/pq to github.com/jackc/pgx/v5HEAD20240905master
lib/pq is out of maintenance for some time now, so switch to the newer more active library. Looks like it finally stabilized after a long time.
Diffstat (limited to 'vendor/golang.org/x/text/unicode/bidi/bidi.go')
-rw-r--r--vendor/golang.org/x/text/unicode/bidi/bidi.go359
1 files changed, 359 insertions, 0 deletions
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)
+}