From c81d09d92bee8f21a79d8bbef3efc6f9f0e36a7e Mon Sep 17 00:00:00 2001
From: Rob Pike <r@golang.org>
Date: Fri, 15 May 2009 15:18:09 -0700
Subject: [PATCH] implement %#o %#x %#X formats

R=rsc
OCL=28936
CL=28936
---
 src/lib/fmt/fmt_test.go |  7 ++++++-
 src/lib/fmt/format.go   | 15 +++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/lib/fmt/fmt_test.go b/src/lib/fmt/fmt_test.go
index e4158624b0e..e8abc2f0d71 100644
--- a/src/lib/fmt/fmt_test.go
+++ b/src/lib/fmt/fmt_test.go
@@ -77,7 +77,6 @@ var fmttests = []fmtTest{
 	fmtTest{ "%+d",		12345,	"+12345" },
 	fmtTest{ "%+d",		-12345,	"-12345" },
 	fmtTest{ "% d",		12345,	" 12345" },
-	fmtTest{ "% d",		-12345,	"-12345" },
 
 	// arrays
 	fmtTest{ "%v",		array,			"[1 2 3 4 5]" },
@@ -92,12 +91,15 @@ var fmttests = []fmtTest{
 	fmtTest{ "%d",		uint32(b32),		"4294967295" },
 	fmtTest{ "%d",		uint64(b64),		"18446744073709551615" },
 	fmtTest{ "%o",		01234,			"1234" },
+	fmtTest{ "%#o",		01234,			"01234" },
 	fmtTest{ "%o",		uint32(b32),		"37777777777" },
 	fmtTest{ "%o",		uint64(b64),		"1777777777777777777777" },
 	fmtTest{ "%x",		0x1234abcd,		"1234abcd" },
+	fmtTest{ "%#x",		0x1234abcd,		"0x1234abcd" },
 	fmtTest{ "%x",		b32-0x1234567,		"fedcba98" },
 	fmtTest{ "%X",		0x1234abcd,		"1234ABCD" },
 	fmtTest{ "%X",		b32-0x1234567,		"FEDCBA98" },
+	fmtTest{ "%#X",		0,		"0X0" },
 	fmtTest{ "%x",		b64,			"ffffffffffffffff" },
 	fmtTest{ "%b",		7,			"111" },
 	fmtTest{ "%b",		b64,			"1111111111111111111111111111111111111111111111111111111111111111" },
@@ -125,6 +127,9 @@ var fmttests = []fmtTest{
 	fmtTest{ "%20d",	1234,			"                1234" },
 	fmtTest{ "%-20.8d",	1234,			"00001234            " },
 	fmtTest{ "%-20.8d",	-1234,			"-00001234           " },
+	fmtTest{ "%-#20.8x",		0x1234abc,		"0x01234abc          " },
+	fmtTest{ "%-#20.8X",		0x1234abc,		"0X01234ABC          " },
+	fmtTest{ "%-#20.8o",		01234,		"00001234            " },
 	fmtTest{ "%.20b",	7,			"00000000000000000111" },
 	fmtTest{ "%20.5s",	"qwertyuiop",		"               qwert" },
 	fmtTest{ "%.5s",	"qwertyuiop",		"qwert" },
diff --git a/src/lib/fmt/format.go b/src/lib/fmt/format.go
index a66440f2615..3cd492980db 100644
--- a/src/lib/fmt/format.go
+++ b/src/lib/fmt/format.go
@@ -202,6 +202,21 @@ func (f *Fmt) integer(a int64, base uint, is_signed bool, digits *string) string
 		i--;
 	}
 
+	if f.sharp {
+		switch base {
+		case 8:
+			if buf[i+1] != '0' {
+				buf[i] = '0';
+				i--;
+			}
+		case 16:
+			buf[i] = 'x' + digits[10]-'a';
+			i--;
+			buf[i] = '0';
+			i--;
+		}
+	}
+
 	if negative {
 		buf[i] = '-';
 		i--;