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Diffstat (limited to 'src/dma/vendor/golang.org/x/text/unicode/bidi/bidi.go')
| -rw-r--r-- | src/dma/vendor/golang.org/x/text/unicode/bidi/bidi.go | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/src/dma/vendor/golang.org/x/text/unicode/bidi/bidi.go b/src/dma/vendor/golang.org/x/text/unicode/bidi/bidi.go new file mode 100644 index 00000000..e8edc54c --- /dev/null +++ b/src/dma/vendor/golang.org/x/text/unicode/bidi/bidi.go @@ -0,0 +1,198 @@ +// 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: +// The following functionality would not be hard to implement, but hinges on +// the definition of a Segmenter interface. For now this is up to the user. +// - Iterate over paragraphs +// - Segmenter to iterate over runs directly from a given text. +// Also: +// - Transformer for reordering? +// - Transformer (validator, really) for Bidi Rule. + +// 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{} + +// 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 { + panic("unimplemented") +} + +// A Paragraph holds a single Paragraph for Bidi processing. +type Paragraph struct { + // buffers +} + +// 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) { + panic("unimplemented") +} + +// SetString 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) SetString(s string, opts ...Option) (n int, err error) { + panic("unimplemented") +} + +// 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 { + panic("unimplemented") +} + +// Direction returns the direction of the text of this paragraph. +// +// The direction may be LeftToRight, RightToLeft, Mixed, or Neutral. +func (p *Paragraph) Direction() Direction { + panic("unimplemented") +} + +// 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 { + panic("unimplemented") +} + +// Order computes the visual ordering of all the runs in a Paragraph. +func (p *Paragraph) Order() (Ordering, error) { + panic("unimplemented") +} + +// 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) { + panic("unimplemented") +} + +// 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{} + +// Direction reports the directionality of the runs. +// +// The direction may be LeftToRight, RightToLeft, Mixed, or Neutral. +func (o *Ordering) Direction() Direction { + panic("unimplemented") +} + +// NumRuns returns the number of runs. +func (o *Ordering) NumRuns() int { + panic("unimplemented") +} + +// Run returns the ith run within the ordering. +func (o *Ordering) Run(i int) Run { + panic("unimplemented") +} + +// 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 { +} + +// String returns the text of the run in its original order. +func (r *Run) String() string { + panic("unimplemented") +} + +// Bytes returns the text of the run in its original order. +func (r *Run) Bytes() []byte { + panic("unimplemented") +} + +// TODO: methods for +// - Display order +// - headers and footers +// - bracket replacement. + +// Direction reports the direction of the run. +func (r *Run) Direction() Direction { + panic("unimplemented") +} + +// Position of the Run within the text passed to SetBytes or SetString of the +// originating Paragraph value. +func (r *Run) Pos() (start, end int) { + panic("unimplemented") +} + +// 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 { + panic("unimplemented") +} + +// 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 { + panic("unimplemented") +} |