Checking in vendor folder for ease of using go get.

vendor/golang.org/x/text/internal/cldrtree/tree.go

@@ -0,0 +1,181 @@
+// Copyright 2017 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 cldrtree
+
+import (
+	"golang.org/x/text/internal"
+	"golang.org/x/text/language"
+)
+
+const (
+	inheritOffsetShift        = 12
+	inheritMask        uint16 = 0x8000
+	inheritValueMask   uint16 = 0x0FFF
+
+	missingValue uint16 = 0xFFFF
+)
+
+// Tree holds a tree of CLDR data.
+type Tree struct {
+	Locales []uint32
+	Indices []uint16
+	Buckets []string
+}
+
+// Lookup looks up CLDR data for the given path. The lookup adheres to the alias
+// and locale inheritance rules as defined in CLDR.
+//
+// Each subsequent element in path indicates which subtree to select data from.
+// The last element of the path must select a leaf node. All other elements
+// of the path select a subindex.
+func (t *Tree) Lookup(tag int, path ...uint16) string {
+	return t.lookup(tag, false, path...)
+}
+
+// LookupFeature is like Lookup, but will first check whether a value of "other"
+// as a fallback before traversing the inheritance chain.
+func (t *Tree) LookupFeature(tag int, path ...uint16) string {
+	return t.lookup(tag, true, path...)
+}
+
+func (t *Tree) lookup(tag int, isFeature bool, path ...uint16) string {
+	origLang := tag
+outer:
+	for {
+		index := t.Indices[t.Locales[tag]:]
+
+		k := uint16(0)
+		for i := range path {
+			max := index[k]
+			if i < len(path)-1 {
+				// index (non-leaf)
+				if path[i] >= max {
+					break
+				}
+				k = index[k+1+path[i]]
+				if k == 0 {
+					break
+				}
+				if v := k &^ inheritMask; k != v {
+					offset := v >> inheritOffsetShift
+					value := v & inheritValueMask
+					path[uint16(i)-offset] = value
+					tag = origLang
+					continue outer
+				}
+			} else {
+				// leaf value
+				offset := missingValue
+				if path[i] < max {
+					offset = index[k+2+path[i]]
+				}
+				if offset == missingValue {
+					if !isFeature {
+						break
+					}
+					// "other" feature must exist
+					offset = index[k+2]
+				}
+				data := t.Buckets[index[k+1]]
+				n := uint16(data[offset])
+				return data[offset+1 : offset+n+1]
+			}
+		}
+		if tag == 0 {
+			break
+		}
+		tag = int(internal.Parent[tag])
+	}
+	return ""
+}
+
+func build(b *Builder) (*Tree, error) {
+	var t Tree
+
+	t.Locales = make([]uint32, language.NumCompactTags)
+
+	for _, loc := range b.locales {
+		tag, _ := language.CompactIndex(loc.tag)
+		t.Locales[tag] = uint32(len(t.Indices))
+		var x indexBuilder
+		x.add(loc.root)
+		t.Indices = append(t.Indices, x.index...)
+	}
+	// Set locales for which we don't have data to the parent's data.
+	for i, v := range t.Locales {
+		p := uint16(i)
+		for v == 0 && p != 0 {
+			p = internal.Parent[p]
+			v = t.Locales[p]
+		}
+		t.Locales[i] = v
+	}
+
+	for _, b := range b.buckets {
+		t.Buckets = append(t.Buckets, string(b))
+	}
+	if b.err != nil {
+		return nil, b.err
+	}
+	return &t, nil
+}
+
+type indexBuilder struct {
+	index []uint16
+}
+
+func (b *indexBuilder) add(i *Index) uint16 {
+	offset := len(b.index)
+
+	max := enumIndex(0)
+	switch {
+	case len(i.values) > 0:
+		for _, v := range i.values {
+			if v.key > max {
+				max = v.key
+			}
+		}
+		b.index = append(b.index, make([]uint16, max+3)...)
+
+		b.index[offset] = uint16(max) + 1
+
+		b.index[offset+1] = i.values[0].value.bucket
+		for i := offset + 2; i < len(b.index); i++ {
+			b.index[i] = missingValue
+		}
+		for _, v := range i.values {
+			b.index[offset+2+int(v.key)] = v.value.bucketPos
+		}
+		return uint16(offset)
+
+	case len(i.subIndex) > 0:
+		for _, s := range i.subIndex {
+			if s.meta.index > max {
+				max = s.meta.index
+			}
+		}
+		b.index = append(b.index, make([]uint16, max+2)...)
+
+		b.index[offset] = uint16(max) + 1
+
+		for _, s := range i.subIndex {
+			x := b.add(s)
+			b.index[offset+int(s.meta.index)+1] = x
+		}
+		return uint16(offset)
+
+	case i.meta.inheritOffset < 0:
+		v := uint16(-(i.meta.inheritOffset + 1)) << inheritOffsetShift
+		p := i.meta
+		for k := i.meta.inheritOffset; k < 0; k++ {
+			p = p.parent
+		}
+		v += uint16(p.typeInfo.enum.lookup(i.meta.inheritIndex))
+		v |= inheritMask
+		return v
+	}
+
+	return 0
+}