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1 files changed, 256 insertions, 0 deletions

diff --git a/vendor/golang.org/x/text/language/parse.go b/vendor/golang.org/x/text/language/parse.go
new file mode 100644
index 0000000..053336e
--- /dev/null
+++ b/vendor/golang.org/x/text/language/parse.go
@@ -0,0 +1,256 @@
+// Copyright 2013 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 language
+
+import (
+        "errors"
+        "sort"
+        "strconv"
+        "strings"
+
+        "golang.org/x/text/internal/language"
+)
+
+// ValueError is returned by any of the parsing functions when the
+// input is well-formed but the respective subtag is not recognized
+// as a valid value.
+type ValueError interface {
+        error
+
+        // Subtag returns the subtag for which the error occurred.
+        Subtag() string
+}
+
+// Parse parses the given BCP 47 string and returns a valid Tag. If parsing
+// failed it returns an error and any part of the tag that could be parsed.
+// If parsing succeeded but an unknown value was found, it returns
+// ValueError. The Tag returned in this case is just stripped of the unknown
+// value. All other values are preserved. It accepts tags in the BCP 47 format
+// and extensions to this standard defined in
+// https://www.unicode.org/reports/tr35/#Unicode_Language_and_Locale_Identifiers.
+// The resulting tag is canonicalized using the default canonicalization type.
+func Parse(s string) (t Tag, err error) {
+        return Default.Parse(s)
+}
+
+// Parse parses the given BCP 47 string and returns a valid Tag. If parsing
+// failed it returns an error and any part of the tag that could be parsed.
+// If parsing succeeded but an unknown value was found, it returns
+// ValueError. The Tag returned in this case is just stripped of the unknown
+// value. All other values are preserved. It accepts tags in the BCP 47 format
+// and extensions to this standard defined in
+// https://www.unicode.org/reports/tr35/#Unicode_Language_and_Locale_Identifiers.
+// The resulting tag is canonicalized using the canonicalization type c.
+func (c CanonType) Parse(s string) (t Tag, err error) {
+        defer func() {
+                if recover() != nil {
+                        t = Tag{}
+                        err = language.ErrSyntax
+                }
+        }()
+
+        tt, err := language.Parse(s)
+        if err != nil {
+                return makeTag(tt), err
+        }
+        tt, changed := canonicalize(c, tt)
+        if changed {
+                tt.RemakeString()
+        }
+        return makeTag(tt), nil
+}
+
+// Compose creates a Tag from individual parts, which may be of type Tag, Base,
+// Script, Region, Variant, []Variant, Extension, []Extension or error. If a
+// Base, Script or Region or slice of type Variant or Extension is passed more
+// than once, the latter will overwrite the former. Variants and Extensions are
+// accumulated, but if two extensions of the same type are passed, the latter
+// will replace the former. For -u extensions, though, the key-type pairs are
+// added, where later values overwrite older ones. A Tag overwrites all former
+// values and typically only makes sense as the first argument. The resulting
+// tag is returned after canonicalizing using the Default CanonType. If one or
+// more errors are encountered, one of the errors is returned.
+func Compose(part ...interface{}) (t Tag, err error) {
+        return Default.Compose(part...)
+}
+
+// Compose creates a Tag from individual parts, which may be of type Tag, Base,
+// Script, Region, Variant, []Variant, Extension, []Extension or error. If a
+// Base, Script or Region or slice of type Variant or Extension is passed more
+// than once, the latter will overwrite the former. Variants and Extensions are
+// accumulated, but if two extensions of the same type are passed, the latter
+// will replace the former. For -u extensions, though, the key-type pairs are
+// added, where later values overwrite older ones. A Tag overwrites all former
+// values and typically only makes sense as the first argument. The resulting
+// tag is returned after canonicalizing using CanonType c. If one or more errors
+// are encountered, one of the errors is returned.
+func (c CanonType) Compose(part ...interface{}) (t Tag, err error) {
+        defer func() {
+                if recover() != nil {
+                        t = Tag{}
+                        err = language.ErrSyntax
+                }
+        }()
+
+        var b language.Builder
+        if err = update(&b, part...); err != nil {
+                return und, err
+        }
+        b.Tag, _ = canonicalize(c, b.Tag)
+        return makeTag(b.Make()), err
+}
+
+var errInvalidArgument = errors.New("invalid Extension or Variant")
+
+func update(b *language.Builder, part ...interface{}) (err error) {
+        for _, x := range part {
+                switch v := x.(type) {
+                case Tag:
+                        b.SetTag(v.tag())
+                case Base:
+                        b.Tag.LangID = v.langID
+                case Script:
+                        b.Tag.ScriptID = v.scriptID
+                case Region:
+                        b.Tag.RegionID = v.regionID
+                case Variant:
+                        if v.variant == "" {
+                                err = errInvalidArgument
+                                break
+                        }
+                        b.AddVariant(v.variant)
+                case Extension:
+                        if v.s == "" {
+                                err = errInvalidArgument
+                                break
+                        }
+                        b.SetExt(v.s)
+                case []Variant:
+                        b.ClearVariants()
+                        for _, v := range v {
+                                b.AddVariant(v.variant)
+                        }
+                case []Extension:
+                        b.ClearExtensions()
+                        for _, e := range v {
+                                b.SetExt(e.s)
+                        }
+                // TODO: support parsing of raw strings based on morphology or just extensions?
+                case error:
+                        if v != nil {
+                                err = v
+                        }
+                }
+        }
+        return
+}
+
+var errInvalidWeight = errors.New("ParseAcceptLanguage: invalid weight")
+var errTagListTooLarge = errors.New("tag list exceeds max length")
+
+// ParseAcceptLanguage parses the contents of an Accept-Language header as
+// defined in http://www.ietf.org/rfc/rfc2616.txt and returns a list of Tags and
+// a list of corresponding quality weights. It is more permissive than RFC 2616
+// and may return non-nil slices even if the input is not valid.
+// The Tags will be sorted by highest weight first and then by first occurrence.
+// Tags with a weight of zero will be dropped. An error will be returned if the
+// input could not be parsed.
+func ParseAcceptLanguage(s string) (tag []Tag, q []float32, err error) {
+        defer func() {
+                if recover() != nil {
+                        tag = nil
+                        q = nil
+                        err = language.ErrSyntax
+                }
+        }()
+
+        if strings.Count(s, "-") > 1000 {
+                return nil, nil, errTagListTooLarge
+        }
+
+        var entry string
+        for s != "" {
+                if entry, s = split(s, ','); entry == "" {
+                        continue
+                }
+
+                entry, weight := split(entry, ';')
+
+                // Scan the language.
+                t, err := Parse(entry)
+                if err != nil {
+                        id, ok := acceptFallback[entry]
+                        if !ok {
+                                return nil, nil, err
+                        }
+                        t = makeTag(language.Tag{LangID: id})
+                }
+
+                // Scan the optional weight.
+                w := 1.0
+                if weight != "" {
+                        weight = consume(weight, 'q')
+                        weight = consume(weight, '=')
+                        // consume returns the empty string when a token could not be
+                        // consumed, resulting in an error for ParseFloat.
+                        if w, err = strconv.ParseFloat(weight, 32); err != nil {
+                                return nil, nil, errInvalidWeight
+                        }
+                        // Drop tags with a quality weight of 0.
+                        if w <= 0 {
+                                continue
+                        }
+                }
+
+                tag = append(tag, t)
+                q = append(q, float32(w))
+        }
+        sort.Stable(&tagSort{tag, q})
+        return tag, q, nil
+}
+
+// consume removes a leading token c from s and returns the result or the empty
+// string if there is no such token.
+func consume(s string, c byte) string {
+        if s == "" || s[0] != c {
+                return ""
+        }
+        return strings.TrimSpace(s[1:])
+}
+
+func split(s string, c byte) (head, tail string) {
+        if i := strings.IndexByte(s, c); i >= 0 {
+                return strings.TrimSpace(s[:i]), strings.TrimSpace(s[i+1:])
+        }
+        return strings.TrimSpace(s), ""
+}
+
+// Add hack mapping to deal with a small number of cases that occur
+// in Accept-Language (with reasonable frequency).
+var acceptFallback = map[string]language.Language{
+        "english": _en,
+        "deutsch": _de,
+        "italian": _it,
+        "french":  _fr,
+        "*":       _mul, // defined in the spec to match all languages.
+}
+
+type tagSort struct {
+        tag []Tag
+        q   []float32
+}
+
+func (s *tagSort) Len() int {
+        return len(s.q)
+}
+
+func (s *tagSort) Less(i, j int) bool {
+        return s.q[i] > s.q[j]
+}
+
+func (s *tagSort) Swap(i, j int) {
+        s.tag[i], s.tag[j] = s.tag[j], s.tag[i]
+        s.q[i], s.q[j] = s.q[j], s.q[i]
+}