strconv: new API

R=golang-dev, bradfitz, gri, r, agl
CC=golang-dev
https://golang.org/cl/5434095

13 files changed, 221 insertions, 269 deletions

diff --git a/src/pkg/strconv/atob.go b/src/pkg/strconv/atob.go
index e2d87bc0f2..1508118d2a 100644
--- a/src/pkg/strconv/atob.go
+++ b/src/pkg/strconv/atob.go
@@ -4,10 +4,10 @@
 
 package strconv
 
-// Atob returns the boolean value represented by the string.
+// ParseBool returns the boolean value represented by the string.
 // It accepts 1, t, T, TRUE, true, True, 0, f, F, FALSE, false, False.
 // Any other value returns an error.
-func Atob(str string) (value bool, err error) {
+func ParseBool(str string) (value bool, err error) {
 	switch str {
 	case "1", "t", "T", "true", "TRUE", "True":
 		return true, nil
@@ -17,10 +17,19 @@ func Atob(str string) (value bool, err error) {
 	return false, &NumError{str, ErrSyntax}
 }
 
-// Btoa returns "true" or "false" according to the value of the boolean argument
-func Btoa(b bool) string {
+// FormatBool returns "true" or "false" according to the value of b
+func FormatBool(b bool) string {
 	if b {
 		return "true"
 	}
 	return "false"
 }
+
+// AppendBool appends "true" or "false", according to the value of b,
+// to dst and returns the extended buffer.
+func AppendBool(dst []byte, b bool) []byte {
+	if b {
+		return append(dst, "true"...)
+	}
+	return append(dst, "false"...)
+}
diff --git a/src/pkg/strconv/atob_test.go b/src/pkg/strconv/atob_test.go
index 2f31eb5e07..a7c1454eb1 100644
--- a/src/pkg/strconv/atob_test.go
+++ b/src/pkg/strconv/atob_test.go
@@ -32,9 +32,9 @@ var atobtests = []atobTest{
 	{"True", true, nil},
 }
 
-func TestAtob(t *testing.T) {
+func TestParseBool(t *testing.T) {
 	for _, test := range atobtests {
-		b, e := Atob(test.in)
+		b, e := ParseBool(test.in)
 		if test.err != nil {
 			// expect an error
 			if e == nil {
diff --git a/src/pkg/strconv/atof.go b/src/pkg/strconv/atof.go
index 06dae8564d..1642c18d74 100644
--- a/src/pkg/strconv/atof.go
+++ b/src/pkg/strconv/atof.go
@@ -338,21 +338,7 @@ func (d *decimal) atof32() (f float32, ok bool) {
 	return
 }
 
-// Atof32 converts the string s to a 32-bit floating-point number.
-//
-// If s is well-formed and near a valid floating point number,
-// Atof32 returns the nearest floating point number rounded
-// using IEEE754 unbiased rounding.
-//
-// The errors that Atof32 returns have concrete type *NumError
-// and include err.Num = s.
-//
-// If s is not syntactically well-formed, Atof32 returns err.Error = ErrSyntax.
-//
-// If s is syntactically well-formed but is more than 1/2 ULP
-// away from the largest floating point number of the given size,
-// Atof32 returns f = ±Inf, err.Error = ErrRange.
-func Atof32(s string) (f float32, err error) {
+func atof32(s string) (f float32, err error) {
 	if val, ok := special(s); ok {
 		return float32(val), nil
 	}
@@ -374,10 +360,7 @@ func Atof32(s string) (f float32, err error) {
 	return f, err
 }
 
-// Atof64 converts the string s to a 64-bit floating-point number.
-// Except for the type of its result, its definition is the same as that
-// of Atof32.
-func Atof64(s string) (f float64, err error) {
+func atof64(s string) (f float64, err error) {
 	if val, ok := special(s); ok {
 		return val, nil
 	}
@@ -399,14 +382,28 @@ func Atof64(s string) (f float64, err error) {
 	return f, err
 }
 
-// AtofN converts the string s to a 64-bit floating-point number,
-// but it rounds the result assuming that it will be stored in a value
-// of n bits (32 or 64).
-func AtofN(s string, n int) (f float64, err error) {
-	if n == 32 {
-		f1, err1 := Atof32(s)
+// ParseFloat converts the string s to a floating-point number
+// with the precision specified by bitSize: 32 for float32, or 64 for float64.
+// When bitSize=32, the result still has type float64, but it will be
+// convertible to float32 without changing its value.
+//
+// If s is well-formed and near a valid floating point number,
+// ParseFloat returns the nearest floating point number rounded
+// using IEEE754 unbiased rounding.
+//
+// The errors that ParseFloat returns have concrete type *NumError
+// and include err.Num = s.
+//
+// If s is not syntactically well-formed, ParseFloat returns err.Error = ErrSyntax.
+//
+// If s is syntactically well-formed but is more than 1/2 ULP
+// away from the largest floating point number of the given size,
+// ParseFloat returns f = ±Inf, err.Error = ErrRange.
+func ParseFloat(s string, bitSize int) (f float64, err error) {
+	if bitSize == 32 {
+		f1, err1 := atof32(s)
 		return float64(f1), err1
 	}
-	f1, err1 := Atof64(s)
+	f1, err1 := atof64(s)
 	return f1, err1
 }
diff --git a/src/pkg/strconv/atof_test.go b/src/pkg/strconv/atof_test.go
index 871bf0cd5e..a9820d1bba 100644
--- a/src/pkg/strconv/atof_test.go
+++ b/src/pkg/strconv/atof_test.go
@@ -128,33 +128,23 @@ func testAtof(t *testing.T, opt bool) {
 	oldopt := SetOptimize(opt)
 	for i := 0; i < len(atoftests); i++ {
 		test := &atoftests[i]
-		out, err := Atof64(test.in)
-		outs := Ftoa64(out, 'g', -1)
+		out, err := ParseFloat(test.in, 64)
+		outs := FormatFloat(out, 'g', -1, 64)
 		if outs != test.out || !reflect.DeepEqual(err, test.err) {
-			t.Errorf("Atof64(%v) = %v, %v want %v, %v",
-				test.in, out, err, test.out, test.err)
-		}
-
-		out, err = AtofN(test.in, 64)
-		outs = FtoaN(out, 'g', -1, 64)
-		if outs != test.out || !reflect.DeepEqual(err, test.err) {
-			t.Errorf("AtofN(%v, 64) = %v, %v want %v, %v",
+			t.Errorf("ParseFloat(%v, 64) = %v, %v want %v, %v",
 				test.in, out, err, test.out, test.err)
 		}
 
 		if float64(float32(out)) == out {
-			out32, err := Atof32(test.in)
-			outs := Ftoa32(out32, 'g', -1)
-			if outs != test.out || !reflect.DeepEqual(err, test.err) {
-				t.Errorf("Atof32(%v) = %v, %v want %v, %v  # %v",
-					test.in, out32, err, test.out, test.err, out)
+			out, err := ParseFloat(test.in, 32)
+			out32 := float32(out)
+			if float64(out32) != out {
+				t.Errorf("ParseFloat(%v, 32) = %v, not a float32 (closest is %v)", test.in, out, float64(out32))
+				continue
 			}
-
-			out, err := AtofN(test.in, 32)
-			out32 = float32(out)
-			outs = FtoaN(float64(out32), 'g', -1, 32)
+			outs := FormatFloat(float64(out32), 'g', -1, 32)
 			if outs != test.out || !reflect.DeepEqual(err, test.err) {
-				t.Errorf("AtofN(%v, 32) = %v, %v want %v, %v  # %v",
+				t.Errorf("ParseFloat(%v, 32) = %v, %v want %v, %v  # %v",
 					test.in, out32, err, test.out, test.err, out)
 			}
 		}
@@ -168,24 +158,24 @@ func TestAtofSlow(t *testing.T) { testAtof(t, false) }
 
 func BenchmarkAtof64Decimal(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		Atof64("33909")
+		ParseFloat("33909", 64)
 	}
 }
 
 func BenchmarkAtof64Float(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		Atof64("339.7784")
+		ParseFloat("339.7784", 64)
 	}
 }
 
 func BenchmarkAtof64FloatExp(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		Atof64("-5.09e75")
+		ParseFloat("-5.09e75", 64)
 	}
 }
 
 func BenchmarkAtof64Big(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		Atof64("123456789123456789123456789")
+		ParseFloat("123456789123456789123456789", 64)
 	}
 }
diff --git a/src/pkg/strconv/atoi.go b/src/pkg/strconv/atoi.go
index 2c6c3d58de..438d496948 100644
--- a/src/pkg/strconv/atoi.go
+++ b/src/pkg/strconv/atoi.go
@@ -20,15 +20,9 @@ type NumError struct {
 
 func (e *NumError) Error() string { return `parsing "` + e.Num + `": ` + e.Err.Error() }
 
-func computeIntsize() uint {
-	siz := uint(8)
-	for 1<<siz != 0 {
-		siz *= 2
-	}
-	return siz
-}
+const intSize = 32 << uint(^uint(0)>>63)
 
-var IntSize = computeIntsize()
+const IntSize = intSize // number of bits in int, uint (32 or 64)
 
 // Return the first number n such that n*base >= 1<<64.
 func cutoff64(base int) uint64 {
@@ -38,17 +32,13 @@ func cutoff64(base int) uint64 {
 	return (1<<64-1)/uint64(base) + 1
 }
 
-// Btoui64 interprets a string s in an arbitrary base b (2 to 36)
-// and returns the corresponding value n.  If b == 0, the base
-// is taken from the string prefix: base 16 for "0x", base 8 for "0",
-// and base 10 otherwise.
-//
-// The errors that Btoui64 returns have concrete type *NumError
-// and include err.Num = s.  If s is empty or contains invalid
-// digits, err.Error = ErrSyntax; if the value corresponding
-// to s cannot be represented by a uint64, err.Error = ErrRange.
-func Btoui64(s string, b int) (n uint64, err error) {
-	var cutoff uint64
+// ParseUint is like ParseInt but for unsigned numbers.
+func ParseUint(s string, b int, bitSize int) (n uint64, err error) {
+	var cutoff, maxVal uint64
+
+	if bitSize == 0 {
+		bitSize = int(IntSize)
+	}
 
 	s0 := s
 	switch {
@@ -82,6 +72,7 @@ func Btoui64(s string, b int) (n uint64, err error) {
 
 	n = 0
 	cutoff = cutoff64(b)
+	maxVal = 1<<uint(bitSize) - 1
 
 	for i := 0; i < len(s); i++ {
 		var v byte
@@ -113,7 +104,7 @@ func Btoui64(s string, b int) (n uint64, err error) {
 		n *= uint64(b)
 
 		n1 := n + uint64(v)
-		if n1 < n {
+		if n1 < n || n1 > maxVal {
 			// n+v overflows
 			n = 1<<64 - 1
 			err = ErrRange
@@ -128,18 +119,25 @@ Error:
 	return n, &NumError{s0, err}
 }
 
-// Atoui64 interprets a string s as a decimal number and
-// returns the corresponding value n.
+// ParseInt interprets a string s in an arbitrary base b (2 to 36)
+// and returns the corresponding value n.  If b == 0, the base
+// is taken from the string prefix: base 16 for "0x", base 8 for "0",
+// and base 10 otherwise.
 //
-// Atoui64 returns err.Error = ErrSyntax if s is empty or contains invalid digits.
-// It returns err.Error = ErrRange if s cannot be represented by a uint64.
-func Atoui64(s string) (n uint64, err error) {
-	return Btoui64(s, 10)
-}
+// The bitSize argument specifies the integer type
+// that the result must fit into.  Bit sizes 0, 8, 16, 32, and 64
+// correspond to int, int8, int16, int32, and int64.
+//
+// The errors that ParseInt returns have concrete type *NumError
+// and include err.Num = s.  If s is empty or contains invalid
+// digits, err.Error = ErrSyntax; if the value corresponding
+// to s cannot be represented by a signed integer of the
+// given size, err.Error = ErrRange.
+func ParseInt(s string, base int, bitSize int) (i int64, err error) {
+	if bitSize == 0 {
+		bitSize = int(IntSize)
+	}
 
-// Btoi64 is like Btoui64 but allows signed numbers and
-// returns its result in an int64.
-func Btoi64(s string, base int) (i int64, err error) {
 	// Empty string bad.
 	if len(s) == 0 {
 		return 0, &NumError{s, ErrSyntax}
@@ -157,16 +155,17 @@ func Btoi64(s string, base int) (i int64, err error) {
 
 	// Convert unsigned and check range.
 	var un uint64
-	un, err = Btoui64(s, base)
+	un, err = ParseUint(s, base, bitSize)
 	if err != nil && err.(*NumError).Err != ErrRange {
 		err.(*NumError).Num = s0
 		return 0, err
 	}
-	if !neg && un >= 1<<63 {
-		return 1<<63 - 1, &NumError{s0, ErrRange}
+	cutoff := uint64(1 << uint(bitSize-1))
+	if !neg && un >= cutoff {
+		return int64(cutoff - 1), &NumError{s0, ErrRange}
 	}
-	if neg && un > 1<<63 {
-		return -1 << 63, &NumError{s0, ErrRange}
+	if neg && un > cutoff {
+		return -int64(cutoff), &NumError{s0, ErrRange}
 	}
 	n := int64(un)
 	if neg {
@@ -175,35 +174,8 @@ func Btoi64(s string, base int) (i int64, err error) {
 	return n, nil
 }
 
-// Atoi64 is like Atoui64 but allows signed numbers and
-// returns its result in an int64.
-func Atoi64(s string) (i int64, err error) { return Btoi64(s, 10) }
-
-// Atoui is like Atoui64 but returns its result as a uint.
-func Atoui(s string) (i uint, err error) {
-	i1, e1 := Atoui64(s)
-	if e1 != nil && e1.(*NumError).Err != ErrRange {
-		return 0, e1
-	}
-	i = uint(i1)
-	if uint64(i) != i1 {
-		return ^uint(0), &NumError{s, ErrRange}
-	}
-	return i, nil
-}
-
-// Atoi is like Atoi64 but returns its result as an int.
+// Atoi is shorthand for ParseInt(s, 10, 0).
 func Atoi(s string) (i int, err error) {
-	i1, e1 := Atoi64(s)
-	if e1 != nil && e1.(*NumError).Err != ErrRange {
-		return 0, e1
-	}
-	i = int(i1)
-	if int64(i) != i1 {
-		if i1 < 0 {
-			return -1 << (IntSize - 1), &NumError{s, ErrRange}
-		}
-		return 1<<(IntSize-1) - 1, &NumError{s, ErrRange}
-	}
-	return i, nil
+	i64, err := ParseInt(s, 10, 0)
+	return int(i64), err
 }
diff --git a/src/pkg/strconv/atoi_test.go b/src/pkg/strconv/atoi_test.go
index 9ee11b7102..2d06efed0d 100644
--- a/src/pkg/strconv/atoi_test.go
+++ b/src/pkg/strconv/atoi_test.go
@@ -187,10 +187,10 @@ func init() {
 	}
 }
 
-func TestAtoui64(t *testing.T) {
+func TestParseUint64(t *testing.T) {
 	for i := range atoui64tests {
 		test := &atoui64tests[i]
-		out, err := Atoui64(test.in)
+		out, err := ParseUint(test.in, 10, 64)
 		if test.out != out || !reflect.DeepEqual(test.err, err) {
 			t.Errorf("Atoui64(%q) = %v, %v want %v, %v",
 				test.in, out, err, test.out, test.err)
@@ -198,21 +198,21 @@ func TestAtoui64(t *testing.T) {
 	}
 }
 
-func TestBtoui64(t *testing.T) {
+func TestParseUint64Base(t *testing.T) {
 	for i := range btoui64tests {
 		test := &btoui64tests[i]
-		out, err := Btoui64(test.in, 0)
+		out, err := ParseUint(test.in, 0, 64)
 		if test.out != out || !reflect.DeepEqual(test.err, err) {
-			t.Errorf("Btoui64(%q) = %v, %v want %v, %v",
+			t.Errorf("ParseUint(%q) = %v, %v want %v, %v",
 				test.in, out, err, test.out, test.err)
 		}
 	}
 }
 
-func TestAtoi64(t *testing.T) {
+func TestParseInt64(t *testing.T) {
 	for i := range atoi64tests {
 		test := &atoi64tests[i]
-		out, err := Atoi64(test.in)
+		out, err := ParseInt(test.in, 10, 64)
 		if test.out != out || !reflect.DeepEqual(test.err, err) {
 			t.Errorf("Atoi64(%q) = %v, %v want %v, %v",
 				test.in, out, err, test.out, test.err)
@@ -220,23 +220,23 @@ func TestAtoi64(t *testing.T) {
 	}
 }
 
-func TestBtoi64(t *testing.T) {
+func TestParseInt64Base(t *testing.T) {
 	for i := range btoi64tests {
 		test := &btoi64tests[i]
-		out, err := Btoi64(test.in, 0)
+		out, err := ParseInt(test.in, 0, 64)
 		if test.out != out || !reflect.DeepEqual(test.err, err) {
-			t.Errorf("Btoi64(%q) = %v, %v want %v, %v",
+			t.Errorf("ParseInt(%q) = %v, %v want %v, %v",
 				test.in, out, err, test.out, test.err)
 		}
 	}
 }
 
-func TestAtoui(t *testing.T) {
+func TestParseUint(t *testing.T) {
 	switch IntSize {
 	case 32:
 		for i := range atoui32tests {
 			test := &atoui32tests[i]
-			out, err := Atoui(test.in)
+			out, err := ParseUint(test.in, 10, 0)
 			if test.out != uint32(out) || !reflect.DeepEqual(test.err, err) {
 				t.Errorf("Atoui(%q) = %v, %v want %v, %v",
 					test.in, out, err, test.out, test.err)
@@ -245,7 +245,7 @@ func TestAtoui(t *testing.T) {
 	case 64:
 		for i := range atoui64tests {
 			test := &atoui64tests[i]
-			out, err := Atoui(test.in)
+			out, err := ParseUint(test.in, 10, 0)
 			if test.out != uint64(out) || !reflect.DeepEqual(test.err, err) {
 				t.Errorf("Atoui(%q) = %v, %v want %v, %v",
 					test.in, out, err, test.out, test.err)
@@ -254,12 +254,12 @@ func TestAtoui(t *testing.T) {
 	}
 }
 
-func TestAtoi(t *testing.T) {
+func TestParseInt(t *testing.T) {
 	switch IntSize {
 	case 32:
 		for i := range atoi32tests {
 			test := &atoi32tests[i]
-			out, err := Atoi(test.in)
+			out, err := ParseInt(test.in, 10, 0)
 			if test.out != int32(out) || !reflect.DeepEqual(test.err, err) {
 				t.Errorf("Atoi(%q) = %v, %v want %v, %v",
 					test.in, out, err, test.out, test.err)
@@ -268,7 +268,7 @@ func TestAtoi(t *testing.T) {
 	case 64:
 		for i := range atoi64tests {
 			test := &atoi64tests[i]
-			out, err := Atoi(test.in)
+			out, err := ParseInt(test.in, 10, 0)
 			if test.out != int64(out) || !reflect.DeepEqual(test.err, err) {
 				t.Errorf("Atoi(%q) = %v, %v want %v, %v",
 					test.in, out, err, test.out, test.err)
@@ -279,24 +279,24 @@ func TestAtoi(t *testing.T) {
 
 func BenchmarkAtoi(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		Atoi("12345678")
+		ParseInt("12345678", 10, 0)
 	}
 }
 
 func BenchmarkAtoiNeg(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		Atoi("-12345678")
+		ParseInt("-12345678", 10, 0)
 	}
 }
 
 func BenchmarkAtoi64(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		Atoi64("12345678901234")
+		ParseInt("12345678901234", 10, 64)
 	}
 }
 
 func BenchmarkAtoi64Neg(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		Atoi64("-12345678901234")
+		ParseInt("-12345678901234", 10, 64)
 	}
 }
diff --git a/src/pkg/strconv/fp_test.go b/src/pkg/strconv/fp_test.go
index 9785ca6916..47877e373a 100644
--- a/src/pkg/strconv/fp_test.go
+++ b/src/pkg/strconv/fp_test.go
@@ -31,7 +31,7 @@ func pow2(i int) float64 {
 func myatof64(s string) (f float64, ok bool) {
 	a := strings.SplitN(s, "p", 2)
 	if len(a) == 2 {
-		n, err := strconv.Atoi64(a[0])
+		n, err := strconv.ParseInt(a[0], 10, 64)
 		if err != nil {
 			return 0, false
 		}
@@ -63,7 +63,7 @@ func myatof64(s string) (f float64, ok bool) {
 		}
 		return v * pow2(e), true
 	}
-	f1, err := strconv.Atof64(s)
+	f1, err := strconv.ParseFloat(s, 64)
 	if err != nil {
 		return 0, false
 	}
@@ -87,7 +87,8 @@ func myatof32(s string) (f float32, ok bool) {
 		}
 		return float32(float64(n) * pow2(e)), true
 	}
-	f1, err1 := strconv.Atof32(s)
+	f64, err1 := strconv.ParseFloat(s, 32)
+	f1 := float32(f64)
 	if err1 != nil {
 		return 0, false
 	}
diff --git a/src/pkg/strconv/ftoa.go b/src/pkg/strconv/ftoa.go
index 8342b6abe7..e1ea0a3503 100644
--- a/src/pkg/strconv/ftoa.go
+++ b/src/pkg/strconv/ftoa.go
@@ -22,8 +22,10 @@ type floatInfo struct {
 var float32info = floatInfo{23, 8, -127}
 var float64info = floatInfo{52, 11, -1023}
 
-// Ftoa32 converts the 32-bit floating-point number f to a string,
-// according to the format fmt and precision prec.
+// FormatFloat converts the floating-point number f to a string,
+// according to the format fmt and precision prec.  It rounds the
+// result assuming that the original was obtained from a floating-point
+// value of bitSize bits (32 for float32, 64 for float64).
 //
 // The format fmt is one of
 // 'b' (-ddddp±ddd, a binary exponent),
@@ -43,24 +45,17 @@ var float64info = floatInfo{52, 11, -1023}
 // Ftoa32(f) is not the same as Ftoa64(float32(f)),
 // because correct rounding and the number of digits
 // needed to identify f depend on the precision of the representation.
-func Ftoa32(f float32, fmt byte, prec int) string {
-	return genericFtoa(uint64(math.Float32bits(f)), fmt, prec, &float32info)
-}
-
-// Ftoa64 is like Ftoa32 but converts a 64-bit floating-point number.
-func Ftoa64(f float64, fmt byte, prec int) string {
+func FormatFloat(f float64, fmt byte, prec int, n int) string {
+	if n == 32 {
+		return genericFtoa(uint64(math.Float32bits(float32(f))), fmt, prec, &float32info)
+	}
 	return genericFtoa(math.Float64bits(f), fmt, prec, &float64info)
 }
 
-// FtoaN converts the 64-bit floating-point number f to a string,
-// according to the format fmt and precision prec, but it rounds the
-// result assuming that it was obtained from a floating-point value
-// of n bits (32 or 64).
-func FtoaN(f float64, fmt byte, prec int, n int) string {
-	if n == 32 {
-		return Ftoa32(float32(f), fmt, prec)
-	}
-	return Ftoa64(f, fmt, prec)
+// AppendFloat appends the string form of the floating-point number f,
+// as generated by FormatFloat, to dst and returns the extended buffer.
+func AppendFloat(dst []byte, f float64, fmt byte, prec int, n int) []byte {
+	return append(dst, FormatFloat(f, fmt, prec, n)...)
 }
 
 func genericFtoa(bits uint64, fmt byte, prec int, flt *floatInfo) string {
diff --git a/src/pkg/strconv/ftoa_test.go b/src/pkg/strconv/ftoa_test.go
index 8bac5da452..02206d5ad2 100644
--- a/src/pkg/strconv/ftoa_test.go
+++ b/src/pkg/strconv/ftoa_test.go
@@ -128,47 +128,47 @@ var ftoatests = []ftoaTest{
 func TestFtoa(t *testing.T) {
 	for i := 0; i < len(ftoatests); i++ {
 		test := &ftoatests[i]
-		s := Ftoa64(test.f, test.fmt, test.prec)
-		if s != test.s {
-			t.Error("test", test.f, string(test.fmt), test.prec, "want", test.s, "got", s)
-		}
-		s = FtoaN(test.f, test.fmt, test.prec, 64)
+		s := FormatFloat(test.f, test.fmt, test.prec, 64)
 		if s != test.s {
 			t.Error("testN=64", test.f, string(test.fmt), test.prec, "want", test.s, "got", s)
 		}
+		x := AppendFloat([]byte("abc"), test.f, test.fmt, test.prec, 64)
+		if string(x) != "abc"+test.s {
+			t.Error("AppendFloat testN=64", test.f, string(test.fmt), test.prec, "want", "abc"+test.s, "got", string(x))
+		}
 		if float64(float32(test.f)) == test.f && test.fmt != 'b' {
-			s := Ftoa32(float32(test.f), test.fmt, test.prec)
-			if s != test.s {
-				t.Error("test32", test.f, string(test.fmt), test.prec, "want", test.s, "got", s)
-			}
-			s = FtoaN(test.f, test.fmt, test.prec, 32)
+			s := FormatFloat(test.f, test.fmt, test.prec, 32)
 			if s != test.s {
 				t.Error("testN=32", test.f, string(test.fmt), test.prec, "want", test.s, "got", s)
 			}
+			x := AppendFloat([]byte("abc"), test.f, test.fmt, test.prec, 32)
+			if string(x) != "abc"+test.s {
+				t.Error("AppendFloat testN=32", test.f, string(test.fmt), test.prec, "want", "abc"+test.s, "got", string(x))
+			}
 		}
 	}
 }
 
 func BenchmarkFtoa64Decimal(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		Ftoa64(33909, 'g', -1)
+		FormatFloat(33909, 'g', -1, 64)
 	}
 }
 
 func BenchmarkFtoa64Float(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		Ftoa64(339.7784, 'g', -1)
+		FormatFloat(339.7784, 'g', -1, 64)
 	}
 }
 
 func BenchmarkFtoa64FloatExp(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		Ftoa64(-5.09e75, 'g', -1)
+		FormatFloat(-5.09e75, 'g', -1, 64)
 	}
 }
 
 func BenchmarkFtoa64Big(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		Ftoa64(123456789123456789123456789, 'g', -1)
+		FormatFloat(123456789123456789123456789, 'g', -1, 64)
 	}
 }
diff --git a/src/pkg/strconv/itoa.go b/src/pkg/strconv/itoa.go
index a0a7496641..29a1a81d86 100644
--- a/src/pkg/strconv/itoa.go
+++ b/src/pkg/strconv/itoa.go
@@ -4,10 +4,11 @@
 
 package strconv
 
-// Uitob64 returns the string representation of i in the given base.
-func Uitob64(u uint64, base uint) string {
+// FormatUint returns the string representation of i in the given base.
+func FormatUint(i uint64, base int) string {
+	u := i
 	if base < 2 || 36 < base {
-		panic("invalid base " + Uitoa(base))
+		panic("invalid base " + Itoa(base))
 	}
 	if u == 0 {
 		return "0"
@@ -26,32 +27,31 @@ func Uitob64(u uint64, base uint) string {
 	return string(buf[j:])
 }
 
-// Itob64 returns the string representation of i in the given base.
-func Itob64(i int64, base uint) string {
+// FormatInt returns the string representation of i in the given base.
+func FormatInt(i int64, base int) string {
 	if i == 0 {
 		return "0"
 	}
 
 	if i < 0 {
-		return "-" + Uitob64(-uint64(i), base)
+		return "-" + FormatUint(-uint64(i), base)
 	}
-	return Uitob64(uint64(i), base)
+	return FormatUint(uint64(i), base)
 }
 
-// Itoa64 returns the decimal string representation of i.
-func Itoa64(i int64) string { return Itob64(i, 10) }
-
-// Uitoa64 returns the decimal string representation of i.
-func Uitoa64(i uint64) string { return Uitob64(i, 10) }
-
-// Uitob returns the string representation of i in the given base.
-func Uitob(i uint, base uint) string { return Uitob64(uint64(i), base) }
-
-// Itob returns the string representation of i in the given base.
-func Itob(i int, base uint) string { return Itob64(int64(i), base) }
+// Itoa is shorthand for FormatInt(i, 10).
+func Itoa(i int) string {
+	return FormatInt(int64(i), 10)
+}
 
-// Itoa returns the decimal string representation of i.
-func Itoa(i int) string { return Itob64(int64(i), 10) }
+// AppendInt appends the string form of the integer i,
+// as generated by FormatInt, to dst and returns the extended buffer.
+func AppendInt(dst []byte, i int64, base int) []byte {
+	return append(dst, FormatInt(i, base)...)
+}
 
-// Uitoa returns the decimal string representation of i.
-func Uitoa(i uint) string { return Uitob64(uint64(i), 10) }
+// AppendUint appends the string form of the unsigned integer i,
+// as generated by FormatUint, to dst and returns the extended buffer.
+func AppendUint(dst []byte, i uint64, base int) []byte {
+	return append(dst, FormatUint(i, base)...)
+}
diff --git a/src/pkg/strconv/itoa_test.go b/src/pkg/strconv/itoa_test.go
index 8514b21e47..99be968fff 100644
--- a/src/pkg/strconv/itoa_test.go
+++ b/src/pkg/strconv/itoa_test.go
@@ -11,7 +11,7 @@ import (
 
 type itob64Test struct {
 	in   int64
-	base uint
+	base int
 	out  string
 }
 
@@ -60,73 +60,43 @@ var itob64tests = []itob64Test{
 
 func TestItoa(t *testing.T) {
 	for _, test := range itob64tests {
-		s := Itob64(test.in, test.base)
+		s := FormatInt(test.in, test.base)
 		if s != test.out {
-			t.Errorf("Itob64(%v, %v) = %v want %v",
+			t.Errorf("FormatInt(%v, %v) = %v want %v",
 				test.in, test.base, s, test.out)
 		}
+		x := AppendInt([]byte("abc"), test.in, test.base)
+		if string(x) != "abc"+test.out {
+			t.Errorf("AppendInt(%q, %v, %v) = %q want %v",
+				"abc", test.in, test.base, x, test.out)
+		}
 
 		if test.in >= 0 {
-			s := Uitob64(uint64(test.in), test.base)
+			s := FormatUint(uint64(test.in), test.base)
 			if s != test.out {
-				t.Errorf("Uitob64(%v, %v) = %v want %v",
+				t.Errorf("FormatUint(%v, %v) = %v want %v",
 					test.in, test.base, s, test.out)
 			}
-		}
-
-		if int64(int(test.in)) == test.in {
-			s := Itob(int(test.in), test.base)
-			if s != test.out {
-				t.Errorf("Itob(%v, %v) = %v want %v",
-					test.in, test.base, s, test.out)
-			}
-
-			if test.in >= 0 {
-				s := Uitob(uint(test.in), test.base)
-				if s != test.out {
-					t.Errorf("Uitob(%v, %v) = %v want %v",
-						test.in, test.base, s, test.out)
-				}
+			x := AppendUint([]byte("abc"), uint64(test.in), test.base)
+			if string(x) != "abc"+test.out {
+				t.Errorf("AppendUint(%q, %v, %v) = %q want %v",
+					"abc", uint64(test.in), test.base, x, test.out)
 			}
 		}
 
-		if test.base == 10 {
-			s := Itoa64(test.in)
+		if test.base == 10 && int64(int(test.in)) == test.in {
+			s := Itoa(int(test.in))
 			if s != test.out {
-				t.Errorf("Itoa64(%v) = %v want %v",
+				t.Errorf("Itoa(%v) = %v want %v",
 					test.in, s, test.out)
 			}
-
-			if test.in >= 0 {
-				s := Uitob64(uint64(test.in), test.base)
-				if s != test.out {
-					t.Errorf("Uitob64(%v, %v) = %v want %v",
-						test.in, test.base, s, test.out)
-				}
-			}
-
-			if int64(int(test.in)) == test.in {
-				s := Itoa(int(test.in))
-				if s != test.out {
-					t.Errorf("Itoa(%v) = %v want %v",
-						test.in, s, test.out)
-				}
-
-				if test.in >= 0 {
-					s := Uitoa(uint(test.in))
-					if s != test.out {
-						t.Errorf("Uitoa(%v) = %v want %v",
-							test.in, s, test.out)
-					}
-				}
-			}
 		}
 	}
 }
 
 type uitob64Test struct {
 	in   uint64
-	base uint
+	base int
 	out  string
 }
 
@@ -141,34 +111,16 @@ var uitob64tests = []uitob64Test{
 
 func TestUitoa(t *testing.T) {
 	for _, test := range uitob64tests {
-		s := Uitob64(test.in, test.base)
+		s := FormatUint(test.in, test.base)
 		if s != test.out {
-			t.Errorf("Uitob64(%v, %v) = %v want %v",
+			t.Errorf("FormatUint(%v, %v) = %v want %v",
 				test.in, test.base, s, test.out)
 		}
-
-		if uint64(uint(test.in)) == test.in {
-			s := Uitob(uint(test.in), test.base)
-			if s != test.out {
-				t.Errorf("Uitob(%v, %v) = %v want %v",
-					test.in, test.base, s, test.out)
-			}
+		x := AppendUint([]byte("abc"), test.in, test.base)
+		if string(x) != "abc"+test.out {
+			t.Errorf("AppendUint(%q, %v, %v) = %q want %v",
+				"abc", test.in, test.base, x, test.out)
 		}
 
-		if test.base == 10 {
-			s := Uitoa64(test.in)
-			if s != test.out {
-				t.Errorf("Uitoa64(%v) = %v want %v",
-					test.in, s, test.out)
-			}
-
-			if uint64(uint(test.in)) == test.in {
-				s := Uitoa(uint(test.in))
-				if s != test.out {
-					t.Errorf("Uitoa(%v) = %v want %v",
-						test.in, s, test.out)
-				}
-			}
-		}
 	}
 }
diff --git a/src/pkg/strconv/quote.go b/src/pkg/strconv/quote.go
index 9b48c07fb1..30b384df8e 100644
--- a/src/pkg/strconv/quote.go
+++ b/src/pkg/strconv/quote.go
@@ -92,6 +92,12 @@ func Quote(s string) string {
 	return quoteWith(s, '"', false)
 }
 
+// AppendQuote appends a double-quoted Go string literal representing s,
+// as generated by Quote, to dst and returns the extended buffer.
+func AppendQuote(dst []byte, s string) []byte {
+	return append(dst, Quote(s)...)
+}
+
 // QuoteToASCII returns a double-quoted Go string literal representing s.
 // The returned string uses Go escape sequences (\t, \n, \xFF, \u0100) for
 // non-ASCII characters and non-printable characters as defined by
@@ -100,6 +106,12 @@ func QuoteToASCII(s string) string {
 	return quoteWith(s, '"', true)
 }
 
+// AppendQuoteToASCII appends a double-quoted Go string literal representing s,
+// as generated by QuoteToASCII, to dst and returns the extended buffer.
+func AppendQuoteToASCII(dst []byte, s string) []byte {
+	return append(dst, QuoteToASCII(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-printable characters as defined by
@@ -109,6 +121,12 @@ func QuoteRune(rune int) string {
 	return quoteWith(string(rune), '\'', false)
 }
 
+// AppendQuoteRune appends a single-quoted Go character literal representing the rune,
+// as generated by QuoteRune, to dst and returns the extended buffer.
+func AppendQuoteRune(dst []byte, rune int) []byte {
+	return append(dst, QuoteRune(rune)...)
+}
+
 // QuoteRuneToASCII returns a single-quoted Go character literal representing
 // the rune.  The returned string uses Go escape sequences (\t, \n, \xFF,
 // \u0100) for non-ASCII characters and non-printable characters as defined
@@ -118,6 +136,12 @@ func QuoteRuneToASCII(rune int) string {
 	return quoteWith(string(rune), '\'', true)
 }
 
+// AppendQuoteRune appends a single-quoted Go character literal representing the rune,
+// as generated by QuoteRuneToASCII, to dst and returns the extended buffer.
+func AppendQuoteRuneToASCII(dst []byte, rune int) []byte {
+	return append(dst, QuoteRuneToASCII(rune)...)
+}
+
 // CanBackquote returns whether the string s would be
 // a valid Go string literal if enclosed in backquotes.
 func CanBackquote(s string) bool {
diff --git a/src/pkg/strconv/quote_test.go b/src/pkg/strconv/quote_test.go
index 9a597700d2..e440797162 100644
--- a/src/pkg/strconv/quote_test.go
+++ b/src/pkg/strconv/quote_test.go
@@ -29,6 +29,9 @@ func TestQuote(t *testing.T) {
 		if out := Quote(tt.in); out != tt.out {
 			t.Errorf("Quote(%s) = %s, want %s", tt.in, out, tt.out)
 		}
+		if out := AppendQuote([]byte("abc"), tt.in); string(out) != "abc"+tt.out {
+			t.Errorf("AppendQuote(%q, %s) = %s, want %s", "abc", tt.in, out, "abc"+tt.out)
+		}
 	}
 }
 
@@ -37,6 +40,9 @@ func TestQuoteToASCII(t *testing.T) {
 		if out := QuoteToASCII(tt.in); out != tt.ascii {
 			t.Errorf("QuoteToASCII(%s) = %s, want %s", tt.in, out, tt.ascii)
 		}
+		if out := AppendQuoteToASCII([]byte("abc"), tt.in); string(out) != "abc"+tt.ascii {
+			t.Errorf("AppendQuoteToASCII(%q, %s) = %s, want %s", "abc", tt.in, out, "abc"+tt.ascii)
+		}
 	}
 }
 
@@ -63,6 +69,9 @@ func TestQuoteRune(t *testing.T) {
 		if out := QuoteRune(tt.in); out != tt.out {
 			t.Errorf("QuoteRune(%U) = %s, want %s", tt.in, out, tt.out)
 		}
+		if out := AppendQuoteRune([]byte("abc"), tt.in); string(out) != "abc"+tt.out {
+			t.Errorf("AppendQuoteRune(%q, %U) = %s, want %s", "abc", tt.in, out, "abc"+tt.out)
+		}
 	}
 }
 
@@ -71,6 +80,9 @@ func TestQuoteRuneToASCII(t *testing.T) {
 		if out := QuoteRuneToASCII(tt.in); out != tt.ascii {
 			t.Errorf("QuoteRuneToASCII(%U) = %s, want %s", tt.in, out, tt.ascii)
 		}
+		if out := AppendQuoteRuneToASCII([]byte("abc"), tt.in); string(out) != "abc"+tt.ascii {
+			t.Errorf("AppendQuoteRuneToASCII(%q, %U) = %s, want %s", "abc", tt.in, out, "abc"+tt.ascii)
+		}
 	}
 }