bytes, strings: IndexOfAny

+ first use in go/doc

R=r
CC=golang-dev
https://golang.org/cl/781041

2 files changed, 31 insertions, 3 deletions

diff --git a/src/pkg/strings/strings.go b/src/pkg/strings/strings.go
index a8f3150c3e..1ceaeefbd4 100644
--- a/src/pkg/strings/strings.go
+++ b/src/pkg/strings/strings.go
@@ -106,6 +106,21 @@ func LastIndex(s, sep string) int {
 	return -1
 }
 
+// IndexAny returns the index of the first instance of any Unicode code point
+// from chars in s, or -1 if no Unicode code point from chars is present in s.
+func IndexAny(s, chars string) int {
+	if len(chars) > 0 {
+		for i, c := range s {
+			for _, m := range chars {
+				if c == m {
+					return i
+				}
+			}
+		}
+	}
+	return -1
+}
+
 // Generic split: splits after each instance of sep,
 // including sepSave bytes of sep in the subarrays.
 func genSplit(s, sep string, sepSave, n int) []string {
diff --git a/src/pkg/strings/strings_test.go b/src/pkg/strings/strings_test.go
index a88f6aae4d..fdf192db63 100644
--- a/src/pkg/strings/strings_test.go
+++ b/src/pkg/strings/strings_test.go
@@ -72,6 +72,20 @@ var lastIndexTests = []IndexTest{
 	IndexTest{"abcABCabc", "a", 6},
 }
 
+var indexAnyTests = []IndexTest{
+	IndexTest{"", "", -1},
+	IndexTest{"", "a", -1},
+	IndexTest{"", "abc", -1},
+	IndexTest{"a", "", -1},
+	IndexTest{"a", "a", 0},
+	IndexTest{"aaa", "a", 0},
+	IndexTest{"abc", "xyz", -1},
+	IndexTest{"abc", "xcz", 2},
+	IndexTest{"a☺b☻c☹d", "uvw☻xyz", 2 + len("☺")},
+	IndexTest{"aRegExp*", ".(|)*+?^$[]", 7},
+	IndexTest{dots + dots + dots, " ", -1},
+}
+
 // Execute f on each test case.  funcName should be the name of f; it's used
 // in failure reports.
 func runIndexTests(t *testing.T, f func(s, sep string) int, funcName string, testCases []IndexTest) {
@@ -83,10 +97,9 @@ func runIndexTests(t *testing.T, f func(s, sep string) int, funcName string, tes
 	}
 }
 
-func TestIndex(t *testing.T) { runIndexTests(t, Index, "Index", indexTests) }
-
+func TestIndex(t *testing.T)     { runIndexTests(t, Index, "Index", indexTests) }
 func TestLastIndex(t *testing.T) { runIndexTests(t, LastIndex, "LastIndex", lastIndexTests) }
-
+func TestIndexAny(t *testing.T)  { runIndexTests(t, IndexAny, "IndexAny", indexAnyTests) }
 
 type ExplodeTest struct {
 	s string