uca

package
v0.17.0-rc1 Latest Latest
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 Go to latest Published: Jun 6, 2023 License: Apache-2.0 Imports: 7 Imported by: 0

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Index

Constants

View Source 
const CodepointsPerPage = 256
View Source 
const MaxCodepoint = 0x10FFFF + 1
View Source 
const MaxCollationElementsPerCodepoint = 8

Variables

This section is empty.

Functions

func PageOffset 

func PageOffset(cp rune) (int, int)

func UnicodeDecomposeHangulSyllable 

func UnicodeDecomposeHangulSyllable(syl rune) []rune

UnicodeDecomposeHangulSyllable breaks down a Korean Hangul rune into its 2 or 3 composited codepoints. This is a straight port of the algorithm in http://www.unicode.org/versions/Unicode9.0.0/ch03.pdf

func UnicodeImplicitWeights900 

func UnicodeImplicitWeights900(weights []uint16, codepoint rune)

UnicodeImplicitWeights900 generates the implicit weights for this codepoint. This is a straight port of the algorithm in https://www.unicode.org/reports/tr10/tr10-34.html#Implicit_Weights It only applies to the UCA Standard v9.0.0

func UnicodeImplicitWeightsLegacy 

func UnicodeImplicitWeightsLegacy(weights []uint16, codepoint rune)

UnicodeImplicitWeightsLegacy generates the implicit weights for this codepoint. This is a straight port of the algorithm in https://www.unicode.org/reports/tr10/tr10-20.html#Implicit_Weights It only applies to the UCA Standard v4.0.0 and v5.2.0

Types

type Collation 

type Collation interface {
	Charset() charset.Charset
	Weights() (Weights, Layout)
	WeightForSpace() uint16
	WeightsEqual(left, right rune) bool
}

type Collation900 

type Collation900 struct {
	// contains filtered or unexported fields
}

func NewCollation 

func NewCollation(name string, weights Weights, weightPatches []Patch, reorder []Reorder, contract Contractor, upperCaseFirst bool, levels int) *Collation900

func (*Collation900) Charset 

func (c *Collation900) Charset() charset.Charset

func (*Collation900) Contractor added in v0.17.0 

func (c *Collation900) Contractor() Contractor

func (*Collation900) Iterator 

func (c *Collation900) Iterator(input []byte) WeightIterator

func (*Collation900) MaxLevel added in v0.17.0 

func (c *Collation900) MaxLevel() int

func (*Collation900) WeightForSpace 

func (c *Collation900) WeightForSpace() uint16

func (*Collation900) Weights 

func (c *Collation900) Weights() (Weights, Layout)

func (*Collation900) WeightsEqual 

func (c *Collation900) WeightsEqual(left, right rune) bool

type CollationLegacy 

type CollationLegacy struct {
	// contains filtered or unexported fields
}

func NewCollationLegacy 

func NewCollationLegacy(cs charset.Charset, weights Weights, weightPatches []Patch, contract Contractor, maxCodepoint rune) *CollationLegacy

func (*CollationLegacy) Charset 

func (c *CollationLegacy) Charset() charset.Charset

func (*CollationLegacy) Contractor added in v0.17.0 

func (c *CollationLegacy) Contractor() Contractor

func (*CollationLegacy) Iterator 

func (c *CollationLegacy) Iterator(input []byte) WeightIteratorLegacy

func (*CollationLegacy) WeightForSpace 

func (c *CollationLegacy) WeightForSpace() uint16

func (*CollationLegacy) Weights 

func (c *CollationLegacy) Weights() (Weights, Layout)

func (*CollationLegacy) WeightsEqual 

func (c *CollationLegacy) WeightsEqual(left, right rune) bool

type Contraction 

type Contraction struct {
	Path       []rune
	Weights    []uint16
	Contextual bool
}

type Contractor 

type Contractor interface {
	Find(cs charset.Charset, cp rune, remainder []byte) ([]uint16, []byte, int)
	FindContextual(cp1, cp0 rune) []uint16
}

func NewTrieContractor 

func NewTrieContractor(all []Contraction) Contractor

type FastIterator900 

type FastIterator900 struct {
	// contains filtered or unexported fields
}

func (*FastIterator900) Done 

func (it *FastIterator900) Done()

func (*FastIterator900) FastForward32 added in v0.14.0 

func (it *FastIterator900) FastForward32(it2 *FastIterator900) int

FastForward32 fast-forwards this iterator and the given it2 in parallel until there is a mismatch in their weights, and returns their difference. This function is similar to NextWeightBlock64 in that it only succeeds if the iterators are composed of (mostly) ASCII characters. See the docs for NextWeightBlock64 for documentation on how these fast comparisons work.

func (*FastIterator900) Level 

func (it *FastIterator900) Level() int

func (*FastIterator900) Next 

func (it *FastIterator900) Next() (uint16, bool)

func (*FastIterator900) NextWeightBlock64 added in v0.14.0 

func (it *FastIterator900) NextWeightBlock64(dstbytes []byte) int

NextWeightBlock64 takes a byte slice of 16 bytes and fills it with the next chunk of weights from this iterator. If the input slice is smaller than 16 bytes, the function will panic.

The function returns the weights in Big Endian ordering: this is the same ordering that MySQL uses when generating weight strings, so the return of this function can be inserted directly into a weight string and the result will be compatible with MySQL. Likewise, the resulting slice can be compared byte-wise (bytes.Compare) to obtain a proper collation ordering against another string.

Returns the number of bytes written to `dstbytes`. If 0, this iterator has been fully consumed.

Implementation notes: This is a fast-path algorithm that can only work for UCA900 collations that do not have reorderings, contractions or any weight patches. The idea is detecting runs of 8 ASCII characters in a row, which are very frequent in most UTF8 code, particularly in English, and generating the weights for these 8 characters directly from an optimized table, instead of going through the whole Unicode Collation Algorithm. This is feasible because in UCA900, all characters in the ASCII range have either 0 or 1 weight triplets, so their weight can be calculated with a single lookup in a 128-entry table for each level (0, 1, 2).

func (*FastIterator900) SkipLevel 

func (it *FastIterator900) SkipLevel() int

type Layout 

type Layout interface {
	MaxCodepoint() rune
	DebugWeights(table Weights, codepoint rune) []uint16
	// contains filtered or unexported methods
}

type Layout_uca900 

type Layout_uca900 struct{}

func (Layout_uca900) DebugWeights 

func (Layout_uca900) DebugWeights(table Weights, codepoint rune) (result []uint16)

func (Layout_uca900) MaxCodepoint 

func (Layout_uca900) MaxCodepoint() rune

type Layout_uca_legacy 

type Layout_uca_legacy struct {
	Max rune
}

func (Layout_uca_legacy) DebugWeights 

func (l Layout_uca_legacy) DebugWeights(table Weights, codepoint rune) (result []uint16)

func (Layout_uca_legacy) MaxCodepoint 

func (l Layout_uca_legacy) MaxCodepoint() rune

type Patch 

type Patch struct {
	Codepoint rune
	Patch     []uint16
}

type Reorder 

type Reorder struct {
	FromMin, FromMax uint16
	ToMin, ToMax     uint16
}

type WeightIterator 

type WeightIterator interface {
	Next() (uint16, bool)
	Level() int
	SkipLevel() int
	Done()
	// contains filtered or unexported methods
}

type WeightIteratorLegacy 

type WeightIteratorLegacy struct {
	// Constant
	*CollationLegacy
	// contains filtered or unexported fields
}

func (*WeightIteratorLegacy) DebugCodepoint 

func (it *WeightIteratorLegacy) DebugCodepoint() (rune, int)

func (*WeightIteratorLegacy) Length 

func (it *WeightIteratorLegacy) Length() int

func (*WeightIteratorLegacy) Next 

func (it *WeightIteratorLegacy) Next() (uint16, bool)

type Weights 

type Weights []*[]uint16

func ApplyTailoring 

func ApplyTailoring(layout Layout, base Weights, patches []Patch) Weights

Source Files

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