libgo: Update to weekly.2012-01-20.

From-SVN: r183540

4 files changed, 28 insertions, 0 deletions

diff --git a/libgo/go/regexp/syntax/compile.go b/libgo/go/regexp/syntax/compile.go
index 21c6565..41955bf 100644
--- a/libgo/go/regexp/syntax/compile.go
+++ b/libgo/go/regexp/syntax/compile.go
@@ -1,3 +1,7 @@
+// Copyright 2011 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 syntax
 
 import "unicode"
diff --git a/libgo/go/regexp/syntax/prog.go b/libgo/go/regexp/syntax/prog.go
index 84ebb83..902d3b3 100644
--- a/libgo/go/regexp/syntax/prog.go
+++ b/libgo/go/regexp/syntax/prog.go
@@ -1,3 +1,7 @@
+// Copyright 2011 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 syntax
 
 import (
diff --git a/libgo/go/regexp/syntax/prog_test.go b/libgo/go/regexp/syntax/prog_test.go
index 70959f6..0d96507 100644
--- a/libgo/go/regexp/syntax/prog_test.go
+++ b/libgo/go/regexp/syntax/prog_test.go
@@ -1,3 +1,7 @@
+// Copyright 2011 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 syntax_test
 
 import (
diff --git a/libgo/go/regexp/syntax/regexp.go b/libgo/go/regexp/syntax/regexp.go
index adcfe29..668a077 100644
--- a/libgo/go/regexp/syntax/regexp.go
+++ b/libgo/go/regexp/syntax/regexp.go
@@ -303,3 +303,19 @@ func (re *Regexp) MaxCap() int {
 	}
 	return m
 }
+
+// CapNames walks the regexp to find the names of capturing groups.
+func (re *Regexp) CapNames() []string {
+	names := make([]string, re.MaxCap()+1)
+	re.capNames(names)
+	return names
+}
+
+func (re *Regexp) capNames(names []string) {
+	if re.Op == OpCapture {
+		names[re.Cap] = re.Name
+	}
+	for _, sub := range re.Sub {
+		sub.capNames(names)
+	}
+}