276 lines
7.1 KiB
Go
276 lines
7.1 KiB
Go
// Copyright 2012 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.
|
|
|
|
package colltab
|
|
|
|
import (
|
|
"unicode/utf8"
|
|
|
|
"golang.org/x/text/unicode/norm"
|
|
)
|
|
|
|
// Table holds all collation data for a given collation ordering.
|
|
type Table struct {
|
|
Index Trie // main trie
|
|
|
|
// expansion info
|
|
ExpandElem []uint32
|
|
|
|
// contraction info
|
|
ContractTries ContractTrieSet
|
|
ContractElem []uint32
|
|
MaxContractLen int
|
|
VariableTop uint32
|
|
}
|
|
|
|
func (t *Table) AppendNext(w []Elem, b []byte) (res []Elem, n int) {
|
|
return t.appendNext(w, source{bytes: b})
|
|
}
|
|
|
|
func (t *Table) AppendNextString(w []Elem, s string) (res []Elem, n int) {
|
|
return t.appendNext(w, source{str: s})
|
|
}
|
|
|
|
func (t *Table) Start(p int, b []byte) int {
|
|
// TODO: implement
|
|
panic("not implemented")
|
|
}
|
|
|
|
func (t *Table) StartString(p int, s string) int {
|
|
// TODO: implement
|
|
panic("not implemented")
|
|
}
|
|
|
|
func (t *Table) Domain() []string {
|
|
// TODO: implement
|
|
panic("not implemented")
|
|
}
|
|
|
|
func (t *Table) Top() uint32 {
|
|
return t.VariableTop
|
|
}
|
|
|
|
type source struct {
|
|
str string
|
|
bytes []byte
|
|
}
|
|
|
|
func (src *source) lookup(t *Table) (ce Elem, sz int) {
|
|
if src.bytes == nil {
|
|
return t.Index.lookupString(src.str)
|
|
}
|
|
return t.Index.lookup(src.bytes)
|
|
}
|
|
|
|
func (src *source) tail(sz int) {
|
|
if src.bytes == nil {
|
|
src.str = src.str[sz:]
|
|
} else {
|
|
src.bytes = src.bytes[sz:]
|
|
}
|
|
}
|
|
|
|
func (src *source) nfd(buf []byte, end int) []byte {
|
|
if src.bytes == nil {
|
|
return norm.NFD.AppendString(buf[:0], src.str[:end])
|
|
}
|
|
return norm.NFD.Append(buf[:0], src.bytes[:end]...)
|
|
}
|
|
|
|
func (src *source) rune() (r rune, sz int) {
|
|
if src.bytes == nil {
|
|
return utf8.DecodeRuneInString(src.str)
|
|
}
|
|
return utf8.DecodeRune(src.bytes)
|
|
}
|
|
|
|
func (src *source) properties(f norm.Form) norm.Properties {
|
|
if src.bytes == nil {
|
|
return f.PropertiesString(src.str)
|
|
}
|
|
return f.Properties(src.bytes)
|
|
}
|
|
|
|
// appendNext appends the weights corresponding to the next rune or
|
|
// contraction in s. If a contraction is matched to a discontinuous
|
|
// sequence of runes, the weights for the interstitial runes are
|
|
// appended as well. It returns a new slice that includes the appended
|
|
// weights and the number of bytes consumed from s.
|
|
func (t *Table) appendNext(w []Elem, src source) (res []Elem, n int) {
|
|
ce, sz := src.lookup(t)
|
|
tp := ce.ctype()
|
|
if tp == ceNormal {
|
|
if ce == 0 {
|
|
r, _ := src.rune()
|
|
const (
|
|
hangulSize = 3
|
|
firstHangul = 0xAC00
|
|
lastHangul = 0xD7A3
|
|
)
|
|
if r >= firstHangul && r <= lastHangul {
|
|
// TODO: performance can be considerably improved here.
|
|
n = sz
|
|
var buf [16]byte // Used for decomposing Hangul.
|
|
for b := src.nfd(buf[:0], hangulSize); len(b) > 0; b = b[sz:] {
|
|
ce, sz = t.Index.lookup(b)
|
|
w = append(w, ce)
|
|
}
|
|
return w, n
|
|
}
|
|
ce = makeImplicitCE(implicitPrimary(r))
|
|
}
|
|
w = append(w, ce)
|
|
} else if tp == ceExpansionIndex {
|
|
w = t.appendExpansion(w, ce)
|
|
} else if tp == ceContractionIndex {
|
|
n := 0
|
|
src.tail(sz)
|
|
if src.bytes == nil {
|
|
w, n = t.matchContractionString(w, ce, src.str)
|
|
} else {
|
|
w, n = t.matchContraction(w, ce, src.bytes)
|
|
}
|
|
sz += n
|
|
} else if tp == ceDecompose {
|
|
// Decompose using NFKD and replace tertiary weights.
|
|
t1, t2 := splitDecompose(ce)
|
|
i := len(w)
|
|
nfkd := src.properties(norm.NFKD).Decomposition()
|
|
for p := 0; len(nfkd) > 0; nfkd = nfkd[p:] {
|
|
w, p = t.appendNext(w, source{bytes: nfkd})
|
|
}
|
|
w[i] = w[i].updateTertiary(t1)
|
|
if i++; i < len(w) {
|
|
w[i] = w[i].updateTertiary(t2)
|
|
for i++; i < len(w); i++ {
|
|
w[i] = w[i].updateTertiary(maxTertiary)
|
|
}
|
|
}
|
|
}
|
|
return w, sz
|
|
}
|
|
|
|
func (t *Table) appendExpansion(w []Elem, ce Elem) []Elem {
|
|
i := splitExpandIndex(ce)
|
|
n := int(t.ExpandElem[i])
|
|
i++
|
|
for _, ce := range t.ExpandElem[i : i+n] {
|
|
w = append(w, Elem(ce))
|
|
}
|
|
return w
|
|
}
|
|
|
|
func (t *Table) matchContraction(w []Elem, ce Elem, suffix []byte) ([]Elem, int) {
|
|
index, n, offset := splitContractIndex(ce)
|
|
|
|
scan := t.ContractTries.scanner(index, n, suffix)
|
|
buf := [norm.MaxSegmentSize]byte{}
|
|
bufp := 0
|
|
p := scan.scan(0)
|
|
|
|
if !scan.done && p < len(suffix) && suffix[p] >= utf8.RuneSelf {
|
|
// By now we should have filtered most cases.
|
|
p0 := p
|
|
bufn := 0
|
|
rune := norm.NFD.Properties(suffix[p:])
|
|
p += rune.Size()
|
|
if rune.LeadCCC() != 0 {
|
|
prevCC := rune.TrailCCC()
|
|
// A gap may only occur in the last normalization segment.
|
|
// This also ensures that len(scan.s) < norm.MaxSegmentSize.
|
|
if end := norm.NFD.FirstBoundary(suffix[p:]); end != -1 {
|
|
scan.s = suffix[:p+end]
|
|
}
|
|
for p < len(suffix) && !scan.done && suffix[p] >= utf8.RuneSelf {
|
|
rune = norm.NFD.Properties(suffix[p:])
|
|
if ccc := rune.LeadCCC(); ccc == 0 || prevCC >= ccc {
|
|
break
|
|
}
|
|
prevCC = rune.TrailCCC()
|
|
if pp := scan.scan(p); pp != p {
|
|
// Copy the interstitial runes for later processing.
|
|
bufn += copy(buf[bufn:], suffix[p0:p])
|
|
if scan.pindex == pp {
|
|
bufp = bufn
|
|
}
|
|
p, p0 = pp, pp
|
|
} else {
|
|
p += rune.Size()
|
|
}
|
|
}
|
|
}
|
|
}
|
|
// Append weights for the matched contraction, which may be an expansion.
|
|
i, n := scan.result()
|
|
ce = Elem(t.ContractElem[i+offset])
|
|
if ce.ctype() == ceNormal {
|
|
w = append(w, ce)
|
|
} else {
|
|
w = t.appendExpansion(w, ce)
|
|
}
|
|
// Append weights for the runes in the segment not part of the contraction.
|
|
for b, p := buf[:bufp], 0; len(b) > 0; b = b[p:] {
|
|
w, p = t.appendNext(w, source{bytes: b})
|
|
}
|
|
return w, n
|
|
}
|
|
|
|
// TODO: unify the two implementations. This is best done after first simplifying
|
|
// the algorithm taking into account the inclusion of both NFC and NFD forms
|
|
// in the table.
|
|
func (t *Table) matchContractionString(w []Elem, ce Elem, suffix string) ([]Elem, int) {
|
|
index, n, offset := splitContractIndex(ce)
|
|
|
|
scan := t.ContractTries.scannerString(index, n, suffix)
|
|
buf := [norm.MaxSegmentSize]byte{}
|
|
bufp := 0
|
|
p := scan.scan(0)
|
|
|
|
if !scan.done && p < len(suffix) && suffix[p] >= utf8.RuneSelf {
|
|
// By now we should have filtered most cases.
|
|
p0 := p
|
|
bufn := 0
|
|
rune := norm.NFD.PropertiesString(suffix[p:])
|
|
p += rune.Size()
|
|
if rune.LeadCCC() != 0 {
|
|
prevCC := rune.TrailCCC()
|
|
// A gap may only occur in the last normalization segment.
|
|
// This also ensures that len(scan.s) < norm.MaxSegmentSize.
|
|
if end := norm.NFD.FirstBoundaryInString(suffix[p:]); end != -1 {
|
|
scan.s = suffix[:p+end]
|
|
}
|
|
for p < len(suffix) && !scan.done && suffix[p] >= utf8.RuneSelf {
|
|
rune = norm.NFD.PropertiesString(suffix[p:])
|
|
if ccc := rune.LeadCCC(); ccc == 0 || prevCC >= ccc {
|
|
break
|
|
}
|
|
prevCC = rune.TrailCCC()
|
|
if pp := scan.scan(p); pp != p {
|
|
// Copy the interstitial runes for later processing.
|
|
bufn += copy(buf[bufn:], suffix[p0:p])
|
|
if scan.pindex == pp {
|
|
bufp = bufn
|
|
}
|
|
p, p0 = pp, pp
|
|
} else {
|
|
p += rune.Size()
|
|
}
|
|
}
|
|
}
|
|
}
|
|
// Append weights for the matched contraction, which may be an expansion.
|
|
i, n := scan.result()
|
|
ce = Elem(t.ContractElem[i+offset])
|
|
if ce.ctype() == ceNormal {
|
|
w = append(w, ce)
|
|
} else {
|
|
w = t.appendExpansion(w, ce)
|
|
}
|
|
// Append weights for the runes in the segment not part of the contraction.
|
|
for b, p := buf[:bufp], 0; len(b) > 0; b = b[p:] {
|
|
w, p = t.appendNext(w, source{bytes: b})
|
|
}
|
|
return w, n
|
|
}
|