1 files changed, 702 insertions, 0 deletions
diff --git a/vendor/golang.org/x/text/collate/build/builder.go b/vendor/golang.org/x/text/collate/build/builder.go
new file mode 100644
index 0000000..1104284
--- /dev/null
+++ b/vendor/golang.org/x/text/collate/build/builder.go
@@ -0,0 +1,702 @@
+// 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 build // import "golang.org/x/text/collate/build"
+
+import (
+	"fmt"
+	"io"
+	"log"
+	"sort"
+	"strings"
+	"unicode/utf8"
+
+	"golang.org/x/text/internal/colltab"
+	"golang.org/x/text/language"
+	"golang.org/x/text/unicode/norm"
+)
+
+// TODO: optimizations:
+// - expandElem is currently 20K. By putting unique colElems in a separate
+//   table and having a byte array of indexes into this table, we can reduce
+//   the total size to about 7K. By also factoring out the length bytes, we
+//   can reduce this to about 6K.
+// - trie valueBlocks are currently 100K. There are a lot of sparse blocks
+//   and many consecutive values with the same stride. This can be further
+//   compacted.
+// - Compress secondary weights into 8 bits.
+// - Some LDML specs specify a context element. Currently we simply concatenate
+//   those.  Context can be implemented using the contraction trie. If Builder
+//   could analyze and detect when using a context makes sense, there is no
+//   need to expose this construct in the API.
+
+// A Builder builds a root collation table.  The user must specify the
+// collation elements for each entry.  A common use will be to base the weights
+// on those specified in the allkeys* file as provided by the UCA or CLDR.
+type Builder struct {
+	index  *trieBuilder
+	root   ordering
+	locale []*Tailoring
+	t      *table
+	err    error
+	built  bool
+
+	minNonVar int // lowest primary recorded for a variable
+	varTop    int // highest primary recorded for a non-variable
+
+	// indexes used for reusing expansions and contractions
+	expIndex map[string]int      // positions of expansions keyed by their string representation
+	ctHandle map[string]ctHandle // contraction handles keyed by a concatenation of the suffixes
+	ctElem   map[string]int      // contraction elements keyed by their string representation
+}
+
+// A Tailoring builds a collation table based on another collation table.
+// The table is defined by specifying tailorings to the underlying table.
+// See http://unicode.org/reports/tr35/ for an overview of tailoring
+// collation tables.  The CLDR contains pre-defined tailorings for a variety
+// of languages (See http://www.unicode.org/Public/cldr/<version>/core.zip.)
+type Tailoring struct {
+	id      string
+	builder *Builder
+	index   *ordering
+
+	anchor *entry
+	before bool
+}
+
+// NewBuilder returns a new Builder.
+func NewBuilder() *Builder {
+	return &Builder{
+		index:    newTrieBuilder(),
+		root:     makeRootOrdering(),
+		expIndex: make(map[string]int),
+		ctHandle: make(map[string]ctHandle),
+		ctElem:   make(map[string]int),
+	}
+}
+
+// Tailoring returns a Tailoring for the given locale.  One should
+// have completed all calls to Add before calling Tailoring.
+func (b *Builder) Tailoring(loc language.Tag) *Tailoring {
+	t := &Tailoring{
+		id:      loc.String(),
+		builder: b,
+		index:   b.root.clone(),
+	}
+	t.index.id = t.id
+	b.locale = append(b.locale, t)
+	return t
+}
+
+// Add adds an entry to the collation element table, mapping
+// a slice of runes to a sequence of collation elements.
+// A collation element is specified as list of weights: []int{primary, secondary, ...}.
+// The entries are typically obtained from a collation element table
+// as defined in http://www.unicode.org/reports/tr10/#Data_Table_Format.
+// Note that the collation elements specified by colelems are only used
+// as a guide.  The actual weights generated by Builder may differ.
+// The argument variables is a list of indices into colelems that should contain
+// a value for each colelem that is a variable. (See the reference above.)
+func (b *Builder) Add(runes []rune, colelems [][]int, variables []int) error {
+	str := string(runes)
+	elems := make([]rawCE, len(colelems))
+	for i, ce := range colelems {
+		if len(ce) == 0 {
+			break
+		}
+		elems[i] = makeRawCE(ce, 0)
+		if len(ce) == 1 {
+			elems[i].w[1] = defaultSecondary
+		}
+		if len(ce) <= 2 {
+			elems[i].w[2] = defaultTertiary
+		}
+		if len(ce) <= 3 {
+			elems[i].w[3] = ce[0]
+		}
+	}
+	for i, ce := range elems {
+		p := ce.w[0]
+		isvar := false
+		for _, j := range variables {
+			if i == j {
+				isvar = true
+			}
+		}
+		if isvar {
+			if p >= b.minNonVar && b.minNonVar > 0 {
+				return fmt.Errorf("primary value %X of variable is larger than the smallest non-variable %X", p, b.minNonVar)
+			}
+			if p > b.varTop {
+				b.varTop = p
+			}
+		} else if p > 1 { // 1 is a special primary value reserved for FFFE
+			if p <= b.varTop {
+				return fmt.Errorf("primary value %X of non-variable is smaller than the highest variable %X", p, b.varTop)
+			}
+			if b.minNonVar == 0 || p < b.minNonVar {
+				b.minNonVar = p
+			}
+		}
+	}
+	elems, err := convertLargeWeights(elems)
+	if err != nil {
+		return err
+	}
+	cccs := []uint8{}
+	nfd := norm.NFD.String(str)
+	for i := range nfd {
+		cccs = append(cccs, norm.NFD.PropertiesString(nfd[i:]).CCC())
+	}
+	if len(cccs) < len(elems) {
+		if len(cccs) > 2 {
+			return fmt.Errorf("number of decomposed characters should be greater or equal to the number of collation elements for len(colelems) > 3 (%d < %d)", len(cccs), len(elems))
+		}
+		p := len(elems) - 1
+		for ; p > 0 && elems[p].w[0] == 0; p-- {
+			elems[p].ccc = cccs[len(cccs)-1]
+		}
+		for ; p >= 0; p-- {
+			elems[p].ccc = cccs[0]
+		}
+	} else {
+		for i := range elems {
+			elems[i].ccc = cccs[i]
+		}
+	}
+	// doNorm in collate.go assumes that the following conditions hold.
+	if len(elems) > 1 && len(cccs) > 1 && cccs[0] != 0 && cccs[0] != cccs[len(cccs)-1] {
+		return fmt.Errorf("incompatible CCC values for expansion %X (%d)", runes, cccs)
+	}
+	b.root.newEntry(str, elems)
+	return nil
+}
+
+func (t *Tailoring) setAnchor(anchor string) error {
+	anchor = norm.NFC.String(anchor)
+	a := t.index.find(anchor)
+	if a == nil {
+		a = t.index.newEntry(anchor, nil)
+		a.implicit = true
+		a.modified = true
+		for _, r := range []rune(anchor) {
+			e := t.index.find(string(r))
+			e.lock = true
+		}
+	}
+	t.anchor = a
+	return nil
+}
+
+// SetAnchor sets the point after which elements passed in subsequent calls to
+// Insert will be inserted.  It is equivalent to the reset directive in an LDML
+// specification.  See Insert for an example.
+// SetAnchor supports the following logical reset positions:
+// <first_tertiary_ignorable/>, <last_teriary_ignorable/>, <first_primary_ignorable/>,
+// and <last_non_ignorable/>.
+func (t *Tailoring) SetAnchor(anchor string) error {
+	if err := t.setAnchor(anchor); err != nil {
+		return err
+	}
+	t.before = false
+	return nil
+}
+
+// SetAnchorBefore is similar to SetAnchor, except that subsequent calls to
+// Insert will insert entries before the anchor.
+func (t *Tailoring) SetAnchorBefore(anchor string) error {
+	if err := t.setAnchor(anchor); err != nil {
+		return err
+	}
+	t.before = true
+	return nil
+}
+
+// Insert sets the ordering of str relative to the entry set by the previous
+// call to SetAnchor or Insert.  The argument extend corresponds
+// to the extend elements as defined in LDML.  A non-empty value for extend
+// will cause the collation elements corresponding to extend to be appended
+// to the collation elements generated for the entry added by Insert.
+// This has the same net effect as sorting str after the string anchor+extend.
+// See http://www.unicode.org/reports/tr10/#Tailoring_Example for details
+// on parametric tailoring and http://unicode.org/reports/tr35/#Collation_Elements
+// for full details on LDML.
+//
+// Examples: create a tailoring for Swedish, where "ä" is ordered after "z"
+// at the primary sorting level:
+//      t := b.Tailoring("se")
+// 		t.SetAnchor("z")
+// 		t.Insert(colltab.Primary, "ä", "")
+// Order "ü" after "ue" at the secondary sorting level:
+//		t.SetAnchor("ue")
+//		t.Insert(colltab.Secondary, "ü","")
+// or
+//		t.SetAnchor("u")
+//		t.Insert(colltab.Secondary, "ü", "e")
+// Order "q" afer "ab" at the secondary level and "Q" after "q"
+// at the tertiary level:
+// 		t.SetAnchor("ab")
+// 		t.Insert(colltab.Secondary, "q", "")
+// 		t.Insert(colltab.Tertiary, "Q", "")
+// Order "b" before "a":
+//      t.SetAnchorBefore("a")
+//      t.Insert(colltab.Primary, "b", "")
+// Order "0" after the last primary ignorable:
+//      t.SetAnchor("<last_primary_ignorable/>")
+//      t.Insert(colltab.Primary, "0", "")
+func (t *Tailoring) Insert(level colltab.Level, str, extend string) error {
+	if t.anchor == nil {
+		return fmt.Errorf("%s:Insert: no anchor point set for tailoring of %s", t.id, str)
+	}
+	str = norm.NFC.String(str)
+	e := t.index.find(str)
+	if e == nil {
+		e = t.index.newEntry(str, nil)
+	} else if e.logical != noAnchor {
+		return fmt.Errorf("%s:Insert: cannot reinsert logical reset position %q", t.id, e.str)
+	}
+	if e.lock {
+		return fmt.Errorf("%s:Insert: cannot reinsert element %q", t.id, e.str)
+	}
+	a := t.anchor
+	// Find the first element after the anchor which differs at a level smaller or
+	// equal to the given level.  Then insert at this position.
+	// See http://unicode.org/reports/tr35/#Collation_Elements, Section 5.14.5 for details.
+	e.before = t.before
+	if t.before {
+		t.before = false
+		if a.prev == nil {
+			a.insertBefore(e)
+		} else {
+			for a = a.prev; a.level > level; a = a.prev {
+			}
+			a.insertAfter(e)
+		}
+		e.level = level
+	} else {
+		for ; a.level > level; a = a.next {
+		}
+		e.level = a.level
+		if a != e {
+			a.insertAfter(e)
+			a.level = level
+		} else {
+			// We don't set a to prev itself. This has the effect of the entry
+			// getting new collation elements that are an increment of itself.
+			// This is intentional.
+			a.prev.level = level
+		}
+	}
+	e.extend = norm.NFD.String(extend)
+	e.exclude = false
+	e.modified = true
+	e.elems = nil
+	t.anchor = e
+	return nil
+}
+
+func (o *ordering) getWeight(e *entry) []rawCE {
+	if len(e.elems) == 0 && e.logical == noAnchor {
+		if e.implicit {
+			for _, r := range e.runes {
+				e.elems = append(e.elems, o.getWeight(o.find(string(r)))...)
+			}
+		} else if e.before {
+			count := [colltab.Identity + 1]int{}
+			a := e
+			for ; a.elems == nil && !a.implicit; a = a.next {
+				count[a.level]++
+			}
+			e.elems = []rawCE{makeRawCE(a.elems[0].w, a.elems[0].ccc)}
+			for i := colltab.Primary; i < colltab.Quaternary; i++ {
+				if count[i] != 0 {
+					e.elems[0].w[i] -= count[i]
+					break
+				}
+			}
+			if e.prev != nil {
+				o.verifyWeights(e.prev, e, e.prev.level)
+			}
+		} else {
+			prev := e.prev
+			e.elems = nextWeight(prev.level, o.getWeight(prev))
+			o.verifyWeights(e, e.next, e.level)
+		}
+	}
+	return e.elems
+}
+
+func (o *ordering) addExtension(e *entry) {
+	if ex := o.find(e.extend); ex != nil {
+		e.elems = append(e.elems, ex.elems...)
+	} else {
+		for _, r := range []rune(e.extend) {
+			e.elems = append(e.elems, o.find(string(r)).elems...)
+		}
+	}
+	e.extend = ""
+}
+
+func (o *ordering) verifyWeights(a, b *entry, level colltab.Level) error {
+	if level == colltab.Identity || b == nil || b.elems == nil || a.elems == nil {
+		return nil
+	}
+	for i := colltab.Primary; i < level; i++ {
+		if a.elems[0].w[i] < b.elems[0].w[i] {
+			return nil
+		}
+	}
+	if a.elems[0].w[level] >= b.elems[0].w[level] {
+		err := fmt.Errorf("%s:overflow: collation elements of %q (%X) overflows those of %q (%X) at level %d (%X >= %X)", o.id, a.str, a.runes, b.str, b.runes, level, a.elems, b.elems)
+		log.Println(err)
+		// TODO: return the error instead, or better, fix the conflicting entry by making room.
+	}
+	return nil
+}
+
+func (b *Builder) error(e error) {
+	if e != nil {
+		b.err = e
+	}
+}
+
+func (b *Builder) errorID(locale string, e error) {
+	if e != nil {
+		b.err = fmt.Errorf("%s:%v", locale, e)
+	}
+}
+
+// patchNorm ensures that NFC and NFD counterparts are consistent.
+func (o *ordering) patchNorm() {
+	// Insert the NFD counterparts, if necessary.
+	for _, e := range o.ordered {
+		nfd := norm.NFD.String(e.str)
+		if nfd != e.str {
+			if e0 := o.find(nfd); e0 != nil && !e0.modified {
+				e0.elems = e.elems
+			} else if e.modified && !equalCEArrays(o.genColElems(nfd), e.elems) {
+				e := o.newEntry(nfd, e.elems)
+				e.modified = true
+			}
+		}
+	}
+	// Update unchanged composed forms if one of their parts changed.
+	for _, e := range o.ordered {
+		nfd := norm.NFD.String(e.str)
+		if e.modified || nfd == e.str {
+			continue
+		}
+		if e0 := o.find(nfd); e0 != nil {
+			e.elems = e0.elems
+		} else {
+			e.elems = o.genColElems(nfd)
+			if norm.NFD.LastBoundary([]byte(nfd)) == 0 {
+				r := []rune(nfd)
+				head := string(r[0])
+				tail := ""
+				for i := 1; i < len(r); i++ {
+					s := norm.NFC.String(head + string(r[i]))
+					if e0 := o.find(s); e0 != nil && e0.modified {
+						head = s
+					} else {
+						tail += string(r[i])
+					}
+				}
+				e.elems = append(o.genColElems(head), o.genColElems(tail)...)
+			}
+		}
+	}
+	// Exclude entries for which the individual runes generate the same collation elements.
+	for _, e := range o.ordered {
+		if len(e.runes) > 1 && equalCEArrays(o.genColElems(e.str), e.elems) {
+			e.exclude = true
+		}
+	}
+}
+
+func (b *Builder) buildOrdering(o *ordering) {
+	for _, e := range o.ordered {
+		o.getWeight(e)
+	}
+	for _, e := range o.ordered {
+		o.addExtension(e)
+	}
+	o.patchNorm()
+	o.sort()
+	simplify(o)
+	b.processExpansions(o)   // requires simplify
+	b.processContractions(o) // requires simplify
+
+	t := newNode()
+	for e := o.front(); e != nil; e, _ = e.nextIndexed() {
+		if !e.skip() {
+			ce, err := e.encode()
+			b.errorID(o.id, err)
+			t.insert(e.runes[0], ce)
+		}
+	}
+	o.handle = b.index.addTrie(t)
+}
+
+func (b *Builder) build() (*table, error) {
+	if b.built {
+		return b.t, b.err
+	}
+	b.built = true
+	b.t = &table{
+		Table: colltab.Table{
+			MaxContractLen: utf8.UTFMax,
+			VariableTop:    uint32(b.varTop),
+		},
+	}
+
+	b.buildOrdering(&b.root)
+	b.t.root = b.root.handle
+	for _, t := range b.locale {
+		b.buildOrdering(t.index)
+		if b.err != nil {
+			break
+		}
+	}
+	i, err := b.index.generate()
+	b.t.trie = *i
+	b.t.Index = colltab.Trie{
+		Index:   i.index,
+		Values:  i.values,
+		Index0:  i.index[blockSize*b.t.root.lookupStart:],
+		Values0: i.values[blockSize*b.t.root.valueStart:],
+	}
+	b.error(err)
+	return b.t, b.err
+}
+
+// Build builds the root Collator.
+func (b *Builder) Build() (colltab.Weighter, error) {
+	table, err := b.build()
+	if err != nil {
+		return nil, err
+	}
+	return table, nil
+}
+
+// Build builds a Collator for Tailoring t.
+func (t *Tailoring) Build() (colltab.Weighter, error) {
+	// TODO: implement.
+	return nil, nil
+}
+
+// Print prints the tables for b and all its Tailorings as a Go file
+// that can be included in the Collate package.
+func (b *Builder) Print(w io.Writer) (n int, err error) {
+	p := func(nn int, e error) {
+		n += nn
+		if err == nil {
+			err = e
+		}
+	}
+	t, err := b.build()
+	if err != nil {
+		return 0, err
+	}
+	p(fmt.Fprintf(w, `var availableLocales = "und`))
+	for _, loc := range b.locale {
+		if loc.id != "und" {
+			p(fmt.Fprintf(w, ",%s", loc.id))
+		}
+	}
+	p(fmt.Fprint(w, "\"\n\n"))
+	p(fmt.Fprintf(w, "const varTop = 0x%x\n\n", b.varTop))
+	p(fmt.Fprintln(w, "var locales = [...]tableIndex{"))
+	for _, loc := range b.locale {
+		if loc.id == "und" {
+			p(t.fprintIndex(w, loc.index.handle, loc.id))
+		}
+	}
+	for _, loc := range b.locale {
+		if loc.id != "und" {
+			p(t.fprintIndex(w, loc.index.handle, loc.id))
+		}
+	}
+	p(fmt.Fprint(w, "}\n\n"))
+	n, _, err = t.fprint(w, "main")
+	return
+}
+
+// reproducibleFromNFKD checks whether the given expansion could be generated
+// from an NFKD expansion.
+func reproducibleFromNFKD(e *entry, exp, nfkd []rawCE) bool {
+	// Length must be equal.
+	if len(exp) != len(nfkd) {
+		return false
+	}
+	for i, ce := range exp {
+		// Primary and secondary values should be equal.
+		if ce.w[0] != nfkd[i].w[0] || ce.w[1] != nfkd[i].w[1] {
+			return false
+		}
+		// Tertiary values should be equal to maxTertiary for third element onwards.
+		// TODO: there seem to be a lot of cases in CLDR (e.g. ㏭ in zh.xml) that can
+		// simply be dropped.  Try this out by dropping the following code.
+		if i >= 2 && ce.w[2] != maxTertiary {
+			return false
+		}
+		if _, err := makeCE(ce); err != nil {
+			// Simply return false. The error will be caught elsewhere.
+			return false
+		}
+	}
+	return true
+}
+
+func simplify(o *ordering) {
+	// Runes that are a starter of a contraction should not be removed.
+	// (To date, there is only Kannada character 0CCA.)
+	keep := make(map[rune]bool)
+	for e := o.front(); e != nil; e, _ = e.nextIndexed() {
+		if len(e.runes) > 1 {
+			keep[e.runes[0]] = true
+		}
+	}
+	// Tag entries for which the runes NFKD decompose to identical values.
+	for e := o.front(); e != nil; e, _ = e.nextIndexed() {
+		s := e.str
+		nfkd := norm.NFKD.String(s)
+		nfd := norm.NFD.String(s)
+		if e.decompose || len(e.runes) > 1 || len(e.elems) == 1 || keep[e.runes[0]] || nfkd == nfd {
+			continue
+		}
+		if reproducibleFromNFKD(e, e.elems, o.genColElems(nfkd)) {
+			e.decompose = true
+		}
+	}
+}
+
+// appendExpansion converts the given collation sequence to
+// collation elements and adds them to the expansion table.
+// It returns an index to the expansion table.
+func (b *Builder) appendExpansion(e *entry) int {
+	t := b.t
+	i := len(t.ExpandElem)
+	ce := uint32(len(e.elems))
+	t.ExpandElem = append(t.ExpandElem, ce)
+	for _, w := range e.elems {
+		ce, err := makeCE(w)
+		if err != nil {
+			b.error(err)
+			return -1
+		}
+		t.ExpandElem = append(t.ExpandElem, ce)
+	}
+	return i
+}
+
+// processExpansions extracts data necessary to generate
+// the extraction tables.
+func (b *Builder) processExpansions(o *ordering) {
+	for e := o.front(); e != nil; e, _ = e.nextIndexed() {
+		if !e.expansion() {
+			continue
+		}
+		key := fmt.Sprintf("%v", e.elems)
+		i, ok := b.expIndex[key]
+		if !ok {
+			i = b.appendExpansion(e)
+			b.expIndex[key] = i
+		}
+		e.expansionIndex = i
+	}
+}
+
+func (b *Builder) processContractions(o *ordering) {
+	// Collate contractions per starter rune.
+	starters := []rune{}
+	cm := make(map[rune][]*entry)
+	for e := o.front(); e != nil; e, _ = e.nextIndexed() {
+		if e.contraction() {
+			if len(e.str) > b.t.MaxContractLen {
+				b.t.MaxContractLen = len(e.str)
+			}
+			r := e.runes[0]
+			if _, ok := cm[r]; !ok {
+				starters = append(starters, r)
+			}
+			cm[r] = append(cm[r], e)
+		}
+	}
+	// Add entries of single runes that are at a start of a contraction.
+	for e := o.front(); e != nil; e, _ = e.nextIndexed() {
+		if !e.contraction() {
+			r := e.runes[0]
+			if _, ok := cm[r]; ok {
+				cm[r] = append(cm[r], e)
+			}
+		}
+	}
+	// Build the tries for the contractions.
+	t := b.t
+	for _, r := range starters {
+		l := cm[r]
+		// Compute suffix strings. There are 31 different contraction suffix
+		// sets for 715 contractions and 82 contraction starter runes as of
+		// version 6.0.0.
+		sufx := []string{}
+		hasSingle := false
+		for _, e := range l {
+			if len(e.runes) > 1 {
+				sufx = append(sufx, string(e.runes[1:]))
+			} else {
+				hasSingle = true
+			}
+		}
+		if !hasSingle {
+			b.error(fmt.Errorf("no single entry for starter rune %U found", r))
+			continue
+		}
+		// Unique the suffix set.
+		sort.Strings(sufx)
+		key := strings.Join(sufx, "\n")
+		handle, ok := b.ctHandle[key]
+		if !ok {
+			var err error
+			handle, err = appendTrie(&t.ContractTries, sufx)
+			if err != nil {
+				b.error(err)
+			}
+			b.ctHandle[key] = handle
+		}
+		// Bucket sort entries in index order.
+		es := make([]*entry, len(l))
+		for _, e := range l {
+			var p, sn int
+			if len(e.runes) > 1 {
+				str := []byte(string(e.runes[1:]))
+				p, sn = lookup(&t.ContractTries, handle, str)
+				if sn != len(str) {
+					log.Fatalf("%s: processContractions: unexpected length for '%X'; len=%d; want %d", o.id, e.runes, sn, len(str))
+				}
+			}
+			if es[p] != nil {
+				log.Fatalf("%s: multiple contractions for position %d for rune %U", o.id, p, e.runes[0])
+			}
+			es[p] = e
+		}
+		// Create collation elements for contractions.
+		elems := []uint32{}
+		for _, e := range es {
+			ce, err := e.encodeBase()
+			b.errorID(o.id, err)
+			elems = append(elems, ce)
+		}
+		key = fmt.Sprintf("%v", elems)
+		i, ok := b.ctElem[key]
+		if !ok {
+			i = len(t.ContractElem)
+			b.ctElem[key] = i
+			t.ContractElem = append(t.ContractElem, elems...)
+		}
+		// Store info in entry for starter rune.
+		es[0].contractionIndex = i
+		es[0].contractionHandle = handle
+	}
+}