strconv: add QuoteRune, which is analogous to Quote, but for runes rather than strings.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/4556059
diff --git a/src/pkg/strconv/quote.go b/src/pkg/strconv/quote.go
index ed58897..bbc0b26 100644
--- a/src/pkg/strconv/quote.go
+++ b/src/pkg/strconv/quote.go
@@ -14,17 +14,14 @@
const lowerhex = "0123456789abcdef"
-// Quote returns a double-quoted Go string literal
-// representing s. The returned string s uses Go escape
-// sequences (\t, \n, \xFF, \u0100) for control characters
-// and non-ASCII characters.
-func Quote(s string) string {
+func quoteWith(s string, quote byte) string {
var buf bytes.Buffer
- buf.WriteByte('"')
+ buf.WriteByte(quote)
for ; len(s) > 0; s = s[1:] {
switch c := s[0]; {
- case c == '"':
- buf.WriteString(`\"`)
+ case c == quote:
+ buf.WriteByte('\\')
+ buf.WriteByte(quote)
case c == '\\':
buf.WriteString(`\\`)
case ' ' <= c && c <= '~':
@@ -69,8 +66,26 @@
buf.WriteByte(lowerhex[c&0xF])
}
}
- buf.WriteByte('"')
+ buf.WriteByte(quote)
return buf.String()
+
+}
+
+// Quote returns a double-quoted Go string literal
+// representing s. The returned string uses Go escape
+// sequences (\t, \n, \xFF, \u0100) for control characters
+// and non-ASCII characters.
+func Quote(s string) string {
+ return quoteWith(s, '"')
+}
+
+// QuoteRune returns a single-quoted Go character literal
+// representing the rune. The returned string uses Go escape
+// sequences (\t, \n, \xFF, \u0100) for control characters
+// and non-ASCII characters.
+func QuoteRune(rune int) string {
+ // TODO: avoid the allocation here.
+ return quoteWith(string(rune), '\'')
}
// CanBackquote returns whether the string s would be
diff --git a/src/pkg/strconv/quote_test.go b/src/pkg/strconv/quote_test.go
index 1235fcb..3232d61 100644
--- a/src/pkg/strconv/quote_test.go
+++ b/src/pkg/strconv/quote_test.go
@@ -25,14 +25,37 @@
}
func TestQuote(t *testing.T) {
- for i := 0; i < len(quotetests); i++ {
- tt := quotetests[i]
+ for _, tt := range quotetests {
if out := Quote(tt.in); out != tt.out {
t.Errorf("Quote(%s) = %s, want %s", tt.in, out, tt.out)
}
}
}
+type quoteRuneTest struct {
+ in int
+ out string
+}
+
+var quoterunetests = []quoteRuneTest{
+ {'a', `'a'`},
+ {'\a', `'\a'`},
+ {'\\', `'\\'`},
+ {0xFF, `'\u00ff'`},
+ {0x263a, `'\u263a'`},
+ {0x0010ffff, `'\U0010ffff'`},
+ {0x0010ffff + 1, `'\ufffd'`},
+ {0x04, `'\x04'`},
+}
+
+func TestQuoteRune(t *testing.T) {
+ for _, tt := range quoterunetests {
+ if out := QuoteRune(tt.in); out != tt.out {
+ t.Errorf("QuoteRune(%U) = %s, want %s", tt.in, out, tt.out)
+ }
+ }
+}
+
type canBackquoteTest struct {
in string
out bool
@@ -80,8 +103,7 @@
}
func TestCanBackquote(t *testing.T) {
- for i := 0; i < len(canbackquotetests); i++ {
- tt := canbackquotetests[i]
+ for _, tt := range canbackquotetests {
if out := CanBackquote(tt.in); out != tt.out {
t.Errorf("CanBackquote(%q) = %v, want %v", tt.in, out, tt.out)
}
@@ -146,23 +168,20 @@
}
func TestUnquote(t *testing.T) {
- for i := 0; i < len(unquotetests); i++ {
- tt := unquotetests[i]
+ for _, tt := range unquotetests {
if out, err := Unquote(tt.in); err != nil && out != tt.out {
t.Errorf("Unquote(%#q) = %q, %v want %q, nil", tt.in, out, err, tt.out)
}
}
// run the quote tests too, backward
- for i := 0; i < len(quotetests); i++ {
- tt := quotetests[i]
+ for _, tt := range quotetests {
if in, err := Unquote(tt.out); in != tt.in {
t.Errorf("Unquote(%#q) = %q, %v, want %q, nil", tt.out, in, err, tt.in)
}
}
- for i := 0; i < len(misquoted); i++ {
- s := misquoted[i]
+ for _, s := range misquoted {
if out, err := Unquote(s); out != "" || err != os.EINVAL {
t.Errorf("Unquote(%#q) = %q, %v want %q, %v", s, out, err, "", os.EINVAL)
}
