ActiveGo 1.8Package bidi
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Constants
UnicodeVersion is the Unicode version from which the tables in this package are derived.
const UnicodeVersion = "9.0.0"
func AppendReverse ¶
func AppendReverse(out, in []byte) []byte
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 ReverseString ¶
func ReverseString(s string) string
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.
type Class ¶
Class is the Unicode BiDi class. Each rune has a single class.
type Class uint
const (
L Class = iota // LeftToRight
R // RightToLeft
EN // EuropeanNumber
ES // EuropeanSeparator
ET // EuropeanTerminator
AN // ArabicNumber
CS // CommonSeparator
B // ParagraphSeparator
S // SegmentSeparator
WS // WhiteSpace
ON // OtherNeutral
BN // BoundaryNeutral
NSM // NonspacingMark
AL // ArabicLetter
Control // Control LRO - PDI
LRO // LeftToRightOverride
RLO // RightToLeftOverride
LRE // LeftToRightEmbedding
RLE // RightToLeftEmbedding
PDF // PopDirectionalFormat
LRI // LeftToRightIsolate
RLI // RightToLeftIsolate
FSI // FirstStrongIsolate
PDI // PopDirectionalIsolate
)
type Direction ¶
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 Option ¶
An Option is an option for Bidi processing.
type Option func(*options)
func DefaultDirection ¶
func DefaultDirection(d Direction) Option
DefaultDirection sets the default direction for a Paragraph. The direction is overridden if the text contains directional characters.
type Ordering ¶
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{}
func (*Ordering) Direction ¶
func (o *Ordering) Direction() Direction
Direction reports the directionality of the runs.
The direction may be LeftToRight, RightToLeft, Mixed, or Neutral.
func (*Ordering) NumRuns ¶
func (o *Ordering) NumRuns() int
NumRuns returns the number of runs.
func (*Ordering) Run ¶
func (o *Ordering) Run(i int) Run
Run returns the ith run within the ordering.
type Paragraph ¶
A Paragraph holds a single Paragraph for Bidi processing.
type Paragraph struct {
}
func (*Paragraph) Direction ¶
func (p *Paragraph) Direction() Direction
Direction returns the direction of the text of this paragraph.
The direction may be LeftToRight, RightToLeft, Mixed, or Neutral.
func (*Paragraph) IsLeftToRight ¶
func (p *Paragraph) IsLeftToRight() bool
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 (*Paragraph) Line ¶
func (p *Paragraph) Line(start, end int) (Ordering, error)
Line computes the visual ordering of runs for a single line starting and ending at the given positions in the original text.
func (*Paragraph) Order ¶
func (p *Paragraph) Order() (Ordering, error)
Order computes the visual ordering of all the runs in a Paragraph.
func (*Paragraph) RunAt ¶
func (p *Paragraph) RunAt(pos int) Run
RunAt reports the Run at the given position of the input text.
This method can be used for computing line breaks on paragraphs.
func (*Paragraph) SetBytes ¶
func (p *Paragraph) SetBytes(b []byte, opts ...Option) (n int, err error)
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 (*Paragraph) SetString ¶
func (p *Paragraph) SetString(s string, opts ...Option) (n int, err error)
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.
type Properties ¶
Properties provides access to BiDi properties of runes.
type Properties struct {
// contains filtered or unexported fields
}
func Lookup ¶
func Lookup(s []byte) (p Properties, sz int)
Lookup returns properties for the first rune in s and the width in bytes of its encoding. The size will be 0 if s does not hold enough bytes to complete the encoding.
func LookupRune ¶
func LookupRune(r rune) (p Properties, size int)
LookupRune returns properties for r.
func LookupString ¶
func LookupString(s string) (p Properties, sz int)
LookupString returns properties for the first rune in s and the width in bytes of its encoding. The size will be 0 if s does not hold enough bytes to complete the encoding.
func (Properties) Class ¶
func (p Properties) Class() Class
Class returns the Bidi class for p.
func (Properties) IsBracket ¶
func (p Properties) IsBracket() bool
IsBracket reports whether the rune is a bracket.
func (Properties) IsOpeningBracket ¶
func (p Properties) IsOpeningBracket() bool
IsOpeningBracket reports whether the rune is an opening bracket. IsBracket must return true.
type Run ¶
A Run is a continuous sequence of characters of a single direction.
type Run struct {
}
func (*Run) Bytes ¶
func (r *Run) Bytes() []byte
Bytes returns the text of the run in its original order.
func (*Run) Direction ¶
func (r *Run) Direction() Direction
Direction reports the direction of the run.
func (*Run) Pos ¶
func (r *Run) Pos() (start, end int)
Position of the Run within the text passed to SetBytes or SetString of the originating Paragraph value.
func (*Run) String ¶
func (r *Run) String() string
String returns the text of the run in its original order.