bytes, strings: IndexOfAny

+ first use in go/doc

R=r
CC=golang-dev
http://codereview.appspot.com/781041

5 files changed, 102 insertions, 28 deletions

diff --git a/src/pkg/bytes/bytes.go b/src/pkg/bytes/bytes.go
index d69af0136..199f63042 100644
--- a/src/pkg/bytes/bytes.go
+++ b/src/pkg/bytes/bytes.go
@@ -125,6 +125,21 @@ func LastIndex(s, sep []byte) int {
 	return -1
 }
 
+// IndexAny returns the index of the first instance of any byte
+// from bytes in s, or -1 if no byte from bytes is present in s.
+func IndexAny(s, bytes []byte) int {
+	if len(bytes) > 0 {
+		for i, b := range s {
+			for _, m := range bytes {
+				if b == 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 []byte, sepSave, n int) [][]byte {
diff --git a/src/pkg/bytes/bytes_test.go b/src/pkg/bytes/bytes_test.go
index 51bed4e50..efec1eb8b 100644
--- a/src/pkg/bytes/bytes_test.go
+++ b/src/pkg/bytes/bytes_test.go
@@ -72,16 +72,19 @@ func TestCompare(t *testing.T) {
 	}
 }
 
-var indextests = []BinOpTest{
+var indexTests = []BinOpTest{
 	BinOpTest{"", "", 0},
-	BinOpTest{"a", "", 0},
 	BinOpTest{"", "a", -1},
-	BinOpTest{"abc", "abc", 0},
-	BinOpTest{"ab", "abc", -1},
-	BinOpTest{"abc", "bc", 1},
-	BinOpTest{"x", "ab", -1},
-	// one-byte tests for IndexByte
-	BinOpTest{"ab", "x", -1},
+	BinOpTest{"", "foo", -1},
+	BinOpTest{"fo", "foo", -1},
+	BinOpTest{"foo", "foo", 0},
+	BinOpTest{"oofofoofooo", "f", 2},
+	BinOpTest{"oofofoofooo", "foo", 4},
+	BinOpTest{"barfoobarfoo", "foo", 3},
+	BinOpTest{"foo", "", 0},
+	BinOpTest{"foo", "o", 1},
+	BinOpTest{"abcABCabc", "A", 3},
+	// cases with one byte strings - test IndexByte and special case in Index()
 	BinOpTest{"", "a", -1},
 	BinOpTest{"x", "a", -1},
 	BinOpTest{"x", "x", 0},
@@ -91,19 +94,54 @@ var indextests = []BinOpTest{
 	BinOpTest{"abc", "x", -1},
 }
 
-func TestIndex(t *testing.T) {
-	for _, tt := range indextests {
-		a := []byte(tt.a)
-		b := []byte(tt.b)
-		pos := Index(a, b)
-		if pos != tt.i {
-			t.Errorf(`Index(%q, %q) = %v`, tt.a, tt.b, pos)
+var lastIndexTests = []BinOpTest{
+	BinOpTest{"", "", 0},
+	BinOpTest{"", "a", -1},
+	BinOpTest{"", "foo", -1},
+	BinOpTest{"fo", "foo", -1},
+	BinOpTest{"foo", "foo", 0},
+	BinOpTest{"foo", "f", 0},
+	BinOpTest{"oofofoofooo", "f", 7},
+	BinOpTest{"oofofoofooo", "foo", 7},
+	BinOpTest{"barfoobarfoo", "foo", 9},
+	BinOpTest{"foo", "", 3},
+	BinOpTest{"foo", "o", 2},
+	BinOpTest{"abcABCabc", "A", 3},
+	BinOpTest{"abcABCabc", "a", 6},
+}
+
+var indexAnyTests = []BinOpTest{
+	BinOpTest{"", "", -1},
+	BinOpTest{"", "a", -1},
+	BinOpTest{"", "abc", -1},
+	BinOpTest{"a", "", -1},
+	BinOpTest{"a", "a", 0},
+	BinOpTest{"aaa", "a", 0},
+	BinOpTest{"abc", "xyz", -1},
+	BinOpTest{"abc", "xcz", 2},
+	BinOpTest{"aRegExp*", ".(|)*+?^$[]", 7},
+	BinOpTest{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 []byte) int, funcName string, testCases []BinOpTest) {
+	for _, test := range testCases {
+		a := []byte(test.a)
+		b := []byte(test.b)
+		actual := f(a, b)
+		if actual != test.i {
+			t.Errorf("%s(%q,%q) = %v; want %v", funcName, a, b, actual, test.i)
 		}
 	}
 }
 
+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) }
+
 func TestIndexByte(t *testing.T) {
-	for _, tt := range indextests {
+	for _, tt := range indexTests {
 		if len(tt.b) != 1 {
 			continue
 		}
diff --git a/src/pkg/go/doc/doc.go b/src/pkg/go/doc/doc.go
index 5ff3eafa6..d7e404f14 100644
--- a/src/pkg/go/doc/doc.go
+++ b/src/pkg/go/doc/doc.go
@@ -10,6 +10,7 @@ import (
 	"go/ast"
 	"go/token"
 	"regexp"
+	"strings"
 	"sort"
 )
 
@@ -564,15 +565,7 @@ func (doc *docReader) newDoc(importpath string, filenames []string) *PackageDoc
 
 // Does s look like a regular expression?
 func isRegexp(s string) bool {
-	metachars := ".(|)*+?^$[]"
-	for _, c := range s {
-		for _, m := range metachars {
-			if c == m {
-				return true
-			}
-		}
-	}
-	return false
+	return strings.IndexAny(s, ".(|)*+?^$[]") >= 0
 }
 
 
diff --git a/src/pkg/strings/strings.go b/src/pkg/strings/strings.go
index a8f3150c3..1ceaeefbd 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 a88f6aae4..fdf192db6 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