language: added PreferSameScript MatchOption
and added match options.
Change-Id: I7c772740515ff557b30fa03be034622b49ea544a
Reviewed-on: https://go-review.googlesource.com/47592
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
Reviewed-by: Nigel Tao <nigeltao@golang.org>
diff --git a/language/match.go b/language/match.go
index 71f1258..63bc744 100644
--- a/language/match.go
+++ b/language/match.go
@@ -6,6 +6,16 @@
import "errors"
+// A MatchOption configures a Matcher.
+type MatchOption func(*matcher)
+
+// PreferSameScript will, in the absence of a match, result in the first
+// preferred tag with the same script as a supported tag to match this supported
+// tag. The default is currently true, but this may change in the future.
+func PreferSameScript(preferSame bool) MatchOption {
+ return func(m *matcher) { m.preferSameScript = preferSame }
+}
+
// Matcher is the interface that wraps the Match method.
//
// Match returns the best match for any of the given tags, along with
@@ -36,8 +46,8 @@
// matched tag in t, but is augmented with the Unicode extension ('u')of the
// corresponding preferred tag. This allows user locale options to be passed
// transparently.
-func NewMatcher(t []Tag) Matcher {
- return newMatcher(t)
+func NewMatcher(t []Tag, options ...MatchOption) Matcher {
+ return newMatcher(t, options)
}
func (m *matcher) Match(want ...Tag) (t Tag, index int, c Confidence) {
@@ -47,18 +57,20 @@
} else {
// TODO: this should be an option
t = m.default_.tag
- outer:
- for _, w := range want {
- script, _ := w.Script()
- if script.scriptID == 0 {
- // Don't do anything if there is no script, such as with
- // private subtags.
- continue
- }
- for i, h := range m.supported {
- if script.scriptID == h.maxScript {
- t, index = h.tag, i
- break outer
+ if m.preferSameScript {
+ outer:
+ for _, w := range want {
+ script, _ := w.Script()
+ if script.scriptID == 0 {
+ // Don't do anything if there is no script, such as with
+ // private subtags.
+ continue
+ }
+ for i, h := range m.supported {
+ if script.scriptID == h.maxScript {
+ t, index = h.tag, i
+ break outer
+ }
}
}
}
@@ -407,10 +419,11 @@
// matcher keeps a set of supported language tags, indexed by language.
type matcher struct {
- default_ *haveTag
- supported []*haveTag
- index map[langID]*matchHeader
- passSettings bool
+ default_ *haveTag
+ supported []*haveTag
+ index map[langID]*matchHeader
+ passSettings bool
+ preferSameScript bool
}
// matchHeader has the lists of tags for exact matches and matches based on
@@ -521,9 +534,13 @@
// newMatcher builds an index for the given supported tags and returns it as
// a matcher. It also expands the index by considering various equivalence classes
// for a given tag.
-func newMatcher(supported []Tag) *matcher {
+func newMatcher(supported []Tag, options []MatchOption) *matcher {
m := &matcher{
- index: make(map[langID]*matchHeader),
+ index: make(map[langID]*matchHeader),
+ preferSameScript: true,
+ }
+ for _, o := range options {
+ o(m)
}
if len(supported) == 0 {
m.default_ = &haveTag{}
diff --git a/language/match_test.go b/language/match_test.go
index cbb847c..4fb56a0 100644
--- a/language/match_test.go
+++ b/language/match_test.go
@@ -381,7 +381,7 @@
func TestBestMatch(t *testing.T) {
for _, tt := range matchTests {
supported := parseSupported(tt.supported)
- m := newMatcher(supported)
+ m := newMatcher(supported, nil)
if *verbose {
fmt.Printf("%s:\n%v\n", tt.comment, m)
}
@@ -475,7 +475,7 @@
}
func BenchmarkMatch(b *testing.B) {
- m := newMatcher(benchHave)
+ m := newMatcher(benchHave, nil)
for i := 0; i < b.N; i++ {
for _, want := range benchWant {
m.getBest(want...)
@@ -485,7 +485,7 @@
func BenchmarkMatchExact(b *testing.B) {
want := mk("en")
- m := newMatcher(benchHave)
+ m := newMatcher(benchHave, nil)
for i := 0; i < b.N; i++ {
m.getBest(want)
}
@@ -493,7 +493,7 @@
func BenchmarkMatchAltLanguagePresent(b *testing.B) {
want := mk("hr")
- m := newMatcher(benchHave)
+ m := newMatcher(benchHave, nil)
for i := 0; i < b.N; i++ {
m.getBest(want)
}
@@ -501,7 +501,7 @@
func BenchmarkMatchAltLanguageNotPresent(b *testing.B) {
want := mk("nn")
- m := newMatcher(benchHave)
+ m := newMatcher(benchHave, nil)
for i := 0; i < b.N; i++ {
m.getBest(want)
}
@@ -509,7 +509,7 @@
func BenchmarkMatchAltScriptPresent(b *testing.B) {
want := mk("zh-Hant-CN")
- m := newMatcher(benchHave)
+ m := newMatcher(benchHave, nil)
for i := 0; i < b.N; i++ {
m.getBest(want)
}
@@ -517,7 +517,7 @@
func BenchmarkMatchAltScriptNotPresent(b *testing.B) {
want := mk("fr-Cyrl")
- m := newMatcher(benchHave)
+ m := newMatcher(benchHave, nil)
for i := 0; i < b.N; i++ {
m.getBest(want)
}
@@ -525,7 +525,7 @@
func BenchmarkMatchLimitedExact(b *testing.B) {
want := []Tag{mk("he-NL"), mk("iw-NL")}
- m := newMatcher(benchHave)
+ m := newMatcher(benchHave, nil)
for i := 0; i < b.N; i++ {
m.getBest(want...)
}
