refactor(util/ascii): simplify AsciiToLowerCase()

Author: marjune163

src/util/ascii.go

@@ -1,18 +1,12 @@
 package util
 
-import "unicode/utf8"
-
 func AsciiToLowerCase(input string) string {
 	buffer := []byte(input)
-	length := len(buffer)
 
-	for i := 0; i < length; {
-		r, w := utf8.DecodeRune(buffer[i:])
-		if w == 1 && r >= 'A' && r <= 'Z' {
+	for i := range buffer {
+		if buffer[i] >= 'A' && buffer[i] <= 'Z' {
 			buffer[i] += 'a' - 'A'
 		}
-
-		i += w
 	}
 
 	return string(buffer)

src/util/ascii_test.go

@@ -10,3 +10,10 @@ func TestAsciiToLowerCase(t *testing.T) {
 		t.Error(lower)
 	}
 }
+
+func BenchmarkAsciiToLowerCase(b *testing.B) {
+	const str = "Confucius said: \"三人行，必有我师焉\""
+	for i := 0; i < b.N; i++ {
+		AsciiToLowerCase(str)
+	}
+}

src/util/path.go

@@ -51,7 +51,7 @@ func NormalizeFsPath(input string) (string, error) {
 
 	volume := filepath.VolumeName(abs)
 	if len(volume) > 0 {
-		// suppose on windows platform, ignore ascii case in path name
+		// assume on windows platform, ignore ascii case in path name
 		abs = AsciiToLowerCase(abs)
 	}