fmt: debugging formats for characters: %+q %#U
%+q uses strconv.Quote[Rune]ToASCII, guaranteeing ASCII-only output.
%#U a quoted character if the rune is printable: 'x'=U+0078; otherwise
it's as before: U+000A.
R=golang-dev, gri, rsc
CC=golang-dev
https://golang.org/cl/4589047
diff --git a/src/pkg/fmt/format.go b/src/pkg/fmt/format.go
index 5dcfb96..bec55f7 100644
--- a/src/pkg/fmt/format.go
+++ b/src/pkg/fmt/format.go
@@ -7,6 +7,7 @@
import (
"bytes"
"strconv"
+ "unicode"
"utf8"
)
@@ -50,6 +51,7 @@
sharp bool
space bool
unicode bool
+ uniQuote bool // Use 'x'= prefix for %U if printable.
zero bool
}
@@ -63,6 +65,7 @@
f.sharp = false
f.space = false
f.unicode = false
+ f.uniQuote = false
f.zero = false
}
@@ -232,6 +235,24 @@
i--
buf[i] = ' '
}
+
+ // If we want a quoted char for %#U, move the data up to make room.
+ if f.unicode && f.uniQuote && a >= 0 && a <= unicode.MaxRune && unicode.IsPrint(int(a)) {
+ runeWidth := utf8.RuneLen(int(a))
+ width := 1 + 1 + runeWidth + 1 // space, quote, rune, quote
+ copy(buf[i-width:], buf[i:]) // guaranteed to have enough room.
+ i -= width
+ // Now put " 'x'" at the end.
+ j := len(buf) - width
+ buf[j] = ' '
+ j++
+ buf[j] = '\''
+ j++
+ utf8.EncodeRune(buf[j:], int(a))
+ j += runeWidth
+ buf[j] = '\''
+ }
+
f.pad(buf[i:])
}
@@ -291,7 +312,11 @@
if f.sharp && strconv.CanBackquote(s) {
quoted = "`" + s + "`"
} else {
- quoted = strconv.Quote(s)
+ if f.plus {
+ quoted = strconv.QuoteToASCII(s)
+ } else {
+ quoted = strconv.Quote(s)
+ }
}
f.padString(quoted)
}
@@ -299,7 +324,12 @@
// fmt_qc formats the integer as a single-quoted, escaped Go character constant.
// If the character is not valid Unicode, it will print '\ufffd'.
func (f *fmt) fmt_qc(c int64) {
- quoted := strconv.QuoteRune(int(c))
+ var quoted string
+ if f.plus {
+ quoted = strconv.QuoteRuneToASCII(int(c))
+ } else {
+ quoted = strconv.QuoteRune(int(c))
+ }
f.padString(quoted)
}
