strconv: use better errors than os.EINVAL, os.ERANGE

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/5327052

src/pkg/exp/sql/convert_test.go

@@ -52,7 +52,7 @@ var conversionTests = []conversionTest{
 	{s: "256", d: &scanuint8, wanterr: `string "256" overflows uint8`},
 	{s: "256", d: &scanuint16, wantuint: 256},
 	{s: "-1", d: &scanint, wantint: -1},
-	{s: "foo", d: &scanint, wanterr: `converting string "foo" to a int: parsing "foo": invalid argument`},
+	{s: "foo", d: &scanint, wanterr: `converting string "foo" to a int: parsing "foo": invalid syntax`},
 }
 
 func intValue(intptr interface{}) int64 {

src/pkg/strconv/atob.go

@@ -16,7 +16,7 @@ func Atob(str string) (value bool, err os.Error) {
 	case "0", "f", "F", "false", "FALSE", "False":
 		return false, nil
 	}
-	return false, &NumError{str, os.EINVAL}
+	return false, &NumError{str, ErrSyntax}
 }
 
 // Btoa returns "true" or "false" according to the value of the boolean argument

src/pkg/strconv/atob_test.go

@@ -17,8 +17,8 @@ type atobTest struct {
 }
 
 var atobtests = []atobTest{
-	{"", false, os.EINVAL},
-	{"asdf", false, os.EINVAL},
+	{"", false, ErrSyntax},
+	{"asdf", false, ErrSyntax},
 	{"0", false, nil},
 	{"f", false, nil},
 	{"F", false, nil},

src/pkg/strconv/atof.go

@@ -350,11 +350,11 @@ func (d *decimal) atof32() (f float32, ok bool) {
 // 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 = os.EINVAL.
+// 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 = os.ERANGE.
+// Atof32 returns f = ±Inf, err.Error = ErrRange.
 func Atof32(s string) (f float32, err os.Error) {
 	if val, ok := special(s); ok {
 		return float32(val), nil
@@ -362,7 +362,7 @@ func Atof32(s string) (f float32, err os.Error) {
 
 	var d decimal
 	if !d.set(s) {
-		return 0, &NumError{s, os.EINVAL}
+		return 0, &NumError{s, ErrSyntax}
 	}
 	if optimize {
 		if f, ok := d.atof32(); ok {
@@ -372,7 +372,7 @@ func Atof32(s string) (f float32, err os.Error) {
 	b, ovf := d.floatBits(&float32info)
 	f = math.Float32frombits(uint32(b))
 	if ovf {
-		err = &NumError{s, os.ERANGE}
+		err = &NumError{s, ErrRange}
 	}
 	return f, err
 }
@@ -387,7 +387,7 @@ func Atof64(s string) (f float64, err os.Error) {
 
 	var d decimal
 	if !d.set(s) {
-		return 0, &NumError{s, os.EINVAL}
+		return 0, &NumError{s, ErrSyntax}
 	}
 	if optimize {
 		if f, ok := d.atof64(); ok {
@@ -397,7 +397,7 @@ func Atof64(s string) (f float64, err os.Error) {
 	b, ovf := d.floatBits(&float64info)
 	f = math.Float64frombits(b)
 	if ovf {
-		err = &NumError{s, os.ERANGE}
+		err = &NumError{s, ErrRange}
 	}
 	return f, err
 }

src/pkg/strconv/atof_test.go

@@ -18,11 +18,11 @@ type atofTest struct {
 }
 
 var atoftests = []atofTest{
-	{"", "0", os.EINVAL},
+	{"", "0", ErrSyntax},
 	{"1", "1", nil},
 	{"+1", "1", nil},
-	{"1x", "0", os.EINVAL},
-	{"1.1.", "0", os.EINVAL},
+	{"1x", "0", ErrSyntax},
+	{"1.1.", "0", ErrSyntax},
 	{"1e23", "1e+23", nil},
 	{"1E23", "1e+23", nil},
 	{"100000000000000000000000", "1e+23", nil},
@@ -56,28 +56,28 @@ var atoftests = []atofTest{
 	{"1.7976931348623157e308", "1.7976931348623157e+308", nil},
 	{"-1.7976931348623157e308", "-1.7976931348623157e+308", nil},
 	// next float64 - too large
-	{"1.7976931348623159e308", "+Inf", os.ERANGE},
-	{"-1.7976931348623159e308", "-Inf", os.ERANGE},
+	{"1.7976931348623159e308", "+Inf", ErrRange},
+	{"-1.7976931348623159e308", "-Inf", ErrRange},
 	// the border is ...158079
 	// borderline - okay
 	{"1.7976931348623158e308", "1.7976931348623157e+308", nil},
 	{"-1.7976931348623158e308", "-1.7976931348623157e+308", nil},
 	// borderline - too large
-	{"1.797693134862315808e308", "+Inf", os.ERANGE},
-	{"-1.797693134862315808e308", "-Inf", os.ERANGE},
+	{"1.797693134862315808e308", "+Inf", ErrRange},
+	{"-1.797693134862315808e308", "-Inf", ErrRange},
 
 	// a little too large
 	{"1e308", "1e+308", nil},
-	{"2e308", "+Inf", os.ERANGE},
-	{"1e309", "+Inf", os.ERANGE},
+	{"2e308", "+Inf", ErrRange},
+	{"1e309", "+Inf", ErrRange},
 
 	// way too large
-	{"1e310", "+Inf", os.ERANGE},
-	{"-1e310", "-Inf", os.ERANGE},
-	{"1e400", "+Inf", os.ERANGE},
-	{"-1e400", "-Inf", os.ERANGE},
-	{"1e400000", "+Inf", os.ERANGE},
-	{"-1e400000", "-Inf", os.ERANGE},
+	{"1e310", "+Inf", ErrRange},
+	{"-1e310", "-Inf", ErrRange},
+	{"1e400", "+Inf", ErrRange},
+	{"-1e400", "-Inf", ErrRange},
+	{"1e400000", "+Inf", ErrRange},
+	{"-1e400000", "-Inf", ErrRange},
 
 	// denormalized
 	{"1e-305", "1e-305", nil},
@@ -99,14 +99,14 @@ var atoftests = []atofTest{
 
 	// try to overflow exponent
 	{"1e-4294967296", "0", nil},
-	{"1e+4294967296", "+Inf", os.ERANGE},
+	{"1e+4294967296", "+Inf", ErrRange},
 	{"1e-18446744073709551616", "0", nil},
-	{"1e+18446744073709551616", "+Inf", os.ERANGE},
+	{"1e+18446744073709551616", "+Inf", ErrRange},
 
 	// Parse errors
-	{"1e", "0", os.EINVAL},
-	{"1e-", "0", os.EINVAL},
-	{".e-1", "0", os.EINVAL},
+	{"1e", "0", ErrSyntax},
+	{"1e-", "0", ErrSyntax},
+	{".e-1", "0", ErrSyntax},
 
 	// http://www.exploringbinary.com/java-hangs-when-converting-2-2250738585072012e-308/
 	{"2.2250738585072012e-308", "2.2250738585072014e-308", nil},

src/pkg/strconv/atoi.go

@@ -6,9 +6,16 @@ package strconv
 
 import "os"
 
+// ErrRange indicates that a value is out of range for the target type.
+var ErrRange = os.NewError("value out of range")
+
+// ErrSyntax indicates that a value does not have the right syntax for the target type.
+var ErrSyntax = os.NewError("invalid syntax")
+
+// A NumError records a failed conversion.
 type NumError struct {
-	Num   string
-	Error os.Error
+	Num   string   // the input
+	Error os.Error // the reason the conversion failed (ErrRange, ErrSyntax)
 }
 
 func (e *NumError) String() string { return `parsing "` + e.Num + `": ` + e.Error.String() }
@@ -38,15 +45,15 @@ func cutoff64(base int) uint64 {
 //
 // The errors that Btoui64 returns have concrete type *NumError
 // and include err.Num = s.  If s is empty or contains invalid
-// digits, err.Error = os.EINVAL; if the value corresponding
-// to s cannot be represented by a uint64, err.Error = os.ERANGE.
+// 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 os.Error) {
 	var cutoff uint64
 
 	s0 := s
 	switch {
 	case len(s) < 1:
-		err = os.EINVAL
+		err = ErrSyntax
 		goto Error
 
 	case 2 <= b && b <= 36:
@@ -59,7 +66,7 @@ func Btoui64(s string, b int) (n uint64, err os.Error) {
 			b = 16
 			s = s[2:]
 			if len(s) < 1 {
-				err = os.EINVAL
+				err = ErrSyntax
 				goto Error
 			}
 		case s[0] == '0':
@@ -88,19 +95,19 @@ func Btoui64(s string, b int) (n uint64, err os.Error) {
 			v = d - 'A' + 10
 		default:
 			n = 0
-			err = os.EINVAL
+			err = ErrSyntax
 			goto Error
 		}
 		if int(v) >= b {
 			n = 0
-			err = os.EINVAL
+			err = ErrSyntax
 			goto Error
 		}
 
 		if n >= cutoff {
 			// n*b overflows
 			n = 1<<64 - 1
-			err = os.ERANGE
+			err = ErrRange
 			goto Error
 		}
 		n *= uint64(b)
@@ -109,7 +116,7 @@ func Btoui64(s string, b int) (n uint64, err os.Error) {
 		if n1 < n {
 			// n+v overflows
 			n = 1<<64 - 1
-			err = os.ERANGE
+			err = ErrRange
 			goto Error
 		}
 		n = n1
@@ -124,8 +131,8 @@ Error:
 // Atoui64 interprets a string s as a decimal number and
 // returns the corresponding value n.
 //
-// Atoui64 returns err == os.EINVAL if s is empty or contains invalid digits.
-// It returns err == os.ERANGE if s cannot be represented by a uint64.
+// 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 os.Error) {
 	return Btoui64(s, 10)
 }
@@ -135,7 +142,7 @@ func Atoui64(s string) (n uint64, err os.Error) {
 func Btoi64(s string, base int) (i int64, err os.Error) {
 	// Empty string bad.
 	if len(s) == 0 {
-		return 0, &NumError{s, os.EINVAL}
+		return 0, &NumError{s, ErrSyntax}
 	}
 
 	// Pick off leading sign.
@@ -151,15 +158,15 @@ func Btoi64(s string, base int) (i int64, err os.Error) {
 	// Convert unsigned and check range.
 	var un uint64
 	un, err = Btoui64(s, base)
-	if err != nil && err.(*NumError).Error != os.ERANGE {
+	if err != nil && err.(*NumError).Error != ErrRange {
 		err.(*NumError).Num = s0
 		return 0, err
 	}
 	if !neg && un >= 1<<63 {
-		return 1<<63 - 1, &NumError{s0, os.ERANGE}
+		return 1<<63 - 1, &NumError{s0, ErrRange}
 	}
 	if neg && un > 1<<63 {
-		return -1 << 63, &NumError{s0, os.ERANGE}
+		return -1 << 63, &NumError{s0, ErrRange}
 	}
 	n := int64(un)
 	if neg {
@@ -175,12 +182,12 @@ func Atoi64(s string) (i int64, err os.Error) { return Btoi64(s, 10) }
 // Atoui is like Atoui64 but returns its result as a uint.
 func Atoui(s string) (i uint, err os.Error) {
 	i1, e1 := Atoui64(s)
-	if e1 != nil && e1.(*NumError).Error != os.ERANGE {
+	if e1 != nil && e1.(*NumError).Error != ErrRange {
 		return 0, e1
 	}
 	i = uint(i1)
 	if uint64(i) != i1 {
-		return ^uint(0), &NumError{s, os.ERANGE}
+		return ^uint(0), &NumError{s, ErrRange}
 	}
 	return i, nil
 }
@@ -188,15 +195,15 @@ func Atoui(s string) (i uint, err os.Error) {
 // Atoi is like Atoi64 but returns its result as an int.
 func Atoi(s string) (i int, err os.Error) {
 	i1, e1 := Atoi64(s)
-	if e1 != nil && e1.(*NumError).Error != os.ERANGE {
+	if e1 != nil && e1.(*NumError).Error != ErrRange {
 		return 0, e1
 	}
 	i = int(i1)
 	if int64(i) != i1 {
 		if i1 < 0 {
-			return -1 << (IntSize - 1), &NumError{s, os.ERANGE}
+			return -1 << (IntSize - 1), &NumError{s, ErrRange}
 		}
-		return 1<<(IntSize-1) - 1, &NumError{s, os.ERANGE}
+		return 1<<(IntSize-1) - 1, &NumError{s, ErrRange}
 	}
 	return i, nil
 }

src/pkg/strconv/atoi_test.go

@@ -18,36 +18,36 @@ type atoui64Test struct {
 }
 
 var atoui64tests = []atoui64Test{
-	{"", 0, os.EINVAL},
+	{"", 0, ErrSyntax},
 	{"0", 0, nil},
 	{"1", 1, nil},
 	{"12345", 12345, nil},
 	{"012345", 12345, nil},
-	{"12345x", 0, os.EINVAL},
+	{"12345x", 0, ErrSyntax},
 	{"98765432100", 98765432100, nil},
 	{"18446744073709551615", 1<<64 - 1, nil},
-	{"18446744073709551616", 1<<64 - 1, os.ERANGE},
-	{"18446744073709551620", 1<<64 - 1, os.ERANGE},
+	{"18446744073709551616", 1<<64 - 1, ErrRange},
+	{"18446744073709551620", 1<<64 - 1, ErrRange},
 }
 
 var btoui64tests = []atoui64Test{
-	{"", 0, os.EINVAL},
+	{"", 0, ErrSyntax},
 	{"0", 0, nil},
 	{"1", 1, nil},
 	{"12345", 12345, nil},
 	{"012345", 012345, nil},
 	{"0x12345", 0x12345, nil},
 	{"0X12345", 0x12345, nil},
-	{"12345x", 0, os.EINVAL},
+	{"12345x", 0, ErrSyntax},
 	{"98765432100", 98765432100, nil},
 	{"18446744073709551615", 1<<64 - 1, nil},
-	{"18446744073709551616", 1<<64 - 1, os.ERANGE},
-	{"18446744073709551620", 1<<64 - 1, os.ERANGE},
+	{"18446744073709551616", 1<<64 - 1, ErrRange},
+	{"18446744073709551620", 1<<64 - 1, ErrRange},
 	{"0xFFFFFFFFFFFFFFFF", 1<<64 - 1, nil},
-	{"0x10000000000000000", 1<<64 - 1, os.ERANGE},
+	{"0x10000000000000000", 1<<64 - 1, ErrRange},
 	{"01777777777777777777777", 1<<64 - 1, nil},
-	{"01777777777777777777778", 0, os.EINVAL},
-	{"02000000000000000000000", 1<<64 - 1, os.ERANGE},
+	{"01777777777777777777778", 0, ErrSyntax},
+	{"02000000000000000000000", 1<<64 - 1, ErrRange},
 	{"0200000000000000000000", 1 << 61, nil},
 }
 
@@ -58,7 +58,7 @@ type atoi64Test struct {
 }
 
 var atoi64tests = []atoi64Test{
-	{"", 0, os.EINVAL},
+	{"", 0, ErrSyntax},
 	{"0", 0, nil},
 	{"-0", 0, nil},
 	{"1", 1, nil},
@@ -71,14 +71,14 @@ var atoi64tests = []atoi64Test{
 	{"-98765432100", -98765432100, nil},
 	{"9223372036854775807", 1<<63 - 1, nil},
 	{"-9223372036854775807", -(1<<63 - 1), nil},
-	{"9223372036854775808", 1<<63 - 1, os.ERANGE},
+	{"9223372036854775808", 1<<63 - 1, ErrRange},
 	{"-9223372036854775808", -1 << 63, nil},
-	{"9223372036854775809", 1<<63 - 1, os.ERANGE},
-	{"-9223372036854775809", -1 << 63, os.ERANGE},
+	{"9223372036854775809", 1<<63 - 1, ErrRange},
+	{"-9223372036854775809", -1 << 63, ErrRange},
 }
 
 var btoi64tests = []atoi64Test{
-	{"", 0, os.EINVAL},
+	{"", 0, ErrSyntax},
 	{"0", 0, nil},
 	{"-0", 0, nil},
 	{"1", 1, nil},
@@ -89,16 +89,16 @@ var btoi64tests = []atoi64Test{
 	{"-012345", -012345, nil},
 	{"0x12345", 0x12345, nil},
 	{"-0X12345", -0x12345, nil},
-	{"12345x", 0, os.EINVAL},
-	{"-12345x", 0, os.EINVAL},
+	{"12345x", 0, ErrSyntax},
+	{"-12345x", 0, ErrSyntax},
 	{"98765432100", 98765432100, nil},
 	{"-98765432100", -98765432100, nil},
 	{"9223372036854775807", 1<<63 - 1, nil},
 	{"-9223372036854775807", -(1<<63 - 1), nil},
-	{"9223372036854775808", 1<<63 - 1, os.ERANGE},
+	{"9223372036854775808", 1<<63 - 1, ErrRange},
 	{"-9223372036854775808", -1 << 63, nil},
-	{"9223372036854775809", 1<<63 - 1, os.ERANGE},
-	{"-9223372036854775809", -1 << 63, os.ERANGE},
+	{"9223372036854775809", 1<<63 - 1, ErrRange},
+	{"-9223372036854775809", -1 << 63, ErrRange},
 }
 
 type atoui32Test struct {
@@ -108,15 +108,15 @@ type atoui32Test struct {
 }
 
 var atoui32tests = []atoui32Test{
-	{"", 0, os.EINVAL},
+	{"", 0, ErrSyntax},
 	{"0", 0, nil},
 	{"1", 1, nil},
 	{"12345", 12345, nil},
 	{"012345", 12345, nil},
-	{"12345x", 0, os.EINVAL},
+	{"12345x", 0, ErrSyntax},
 	{"987654321", 987654321, nil},
 	{"4294967295", 1<<32 - 1, nil},
-	{"4294967296", 1<<32 - 1, os.ERANGE},
+	{"4294967296", 1<<32 - 1, ErrRange},
 }
 
 type atoi32Test struct {
@@ -126,7 +126,7 @@ type atoi32Test struct {
 }
 
 var atoi32tests = []atoi32Test{
-	{"", 0, os.EINVAL},
+	{"", 0, ErrSyntax},
 	{"0", 0, nil},
 	{"-0", 0, nil},
 	{"1", 1, nil},
@@ -135,16 +135,16 @@ var atoi32tests = []atoi32Test{
 	{"-12345", -12345, nil},
 	{"012345", 12345, nil},
 	{"-012345", -12345, nil},
-	{"12345x", 0, os.EINVAL},
-	{"-12345x", 0, os.EINVAL},
+	{"12345x", 0, ErrSyntax},
+	{"-12345x", 0, ErrSyntax},
 	{"987654321", 987654321, nil},
 	{"-987654321", -987654321, nil},
 	{"2147483647", 1<<31 - 1, nil},
 	{"-2147483647", -(1<<31 - 1), nil},
-	{"2147483648", 1<<31 - 1, os.ERANGE},
+	{"2147483648", 1<<31 - 1, ErrRange},
 	{"-2147483648", -1 << 31, nil},
-	{"2147483649", 1<<31 - 1, os.ERANGE},
-	{"-2147483649", -1 << 31, os.ERANGE},
+	{"2147483649", 1<<31 - 1, ErrRange},
+	{"-2147483649", -1 << 31, ErrRange},
 }
 
 func init() {

src/pkg/strconv/quote.go

@@ -161,7 +161,7 @@ func UnquoteChar(s string, quote byte) (value rune, multibyte bool, tail string,
 	// easy cases
 	switch c := s[0]; {
 	case c == quote && (quote == '\'' || quote == '"'):
-		err = os.EINVAL
+		err = ErrSyntax
 		return
 	case c >= utf8.RuneSelf:
 		r, size := utf8.DecodeRuneInString(s)
@@ -172,7 +172,7 @@ func UnquoteChar(s string, quote byte) (value rune, multibyte bool, tail string,
 
 	// hard case: c is backslash
 	if len(s) <= 1 {
-		err = os.EINVAL
+		err = ErrSyntax
 		return
 	}
 	c := s[1]
@@ -205,13 +205,13 @@ func UnquoteChar(s string, quote byte) (value rune, multibyte bool, tail string,
 		}
 		var v rune
 		if len(s) < n {
-			err = os.EINVAL
+			err = ErrSyntax
 			return
 		}
 		for j := 0; j < n; j++ {
 			x, ok := unhex(s[j])
 			if !ok {
-				err = os.EINVAL
+				err = ErrSyntax
 				return
 			}
 			v = v<<4 | x
@@ -223,7 +223,7 @@ func UnquoteChar(s string, quote byte) (value rune, multibyte bool, tail string,
 			break
 		}
 		if v > unicode.MaxRune {
-			err = os.EINVAL
+			err = ErrSyntax
 			return
 		}
 		value = v
@@ -231,7 +231,7 @@ func UnquoteChar(s string, quote byte) (value rune, multibyte bool, tail string,
 	case '0', '1', '2', '3', '4', '5', '6', '7':
 		v := rune(c) - '0'
 		if len(s) < 2 {
-			err = os.EINVAL
+			err = ErrSyntax
 			return
 		}
 		for j := 0; j < 2; j++ { // one digit already; two more
@@ -243,7 +243,7 @@ func UnquoteChar(s string, quote byte) (value rune, multibyte bool, tail string,
 		}
 		s = s[2:]
 		if v > 255 {
-			err = os.EINVAL
+			err = ErrSyntax
 			return
 		}
 		value = v
@@ -251,12 +251,12 @@ func UnquoteChar(s string, quote byte) (value rune, multibyte bool, tail string,
 		value = '\\'
 	case '\'', '"':
 		if c != quote {
-			err = os.EINVAL
+			err = ErrSyntax
 			return
 		}
 		value = rune(c)
 	default:
-		err = os.EINVAL
+		err = ErrSyntax
 		return
 	}
 	tail = s
@@ -271,25 +271,25 @@ func UnquoteChar(s string, quote byte) (value rune, multibyte bool, tail string,
 func Unquote(s string) (t string, err os.Error) {
 	n := len(s)
 	if n < 2 {
-		return "", os.EINVAL
+		return "", ErrSyntax
 	}
 	quote := s[0]
 	if quote != s[n-1] {
-		return "", os.EINVAL
+		return "", ErrSyntax
 	}
 	s = s[1 : n-1]
 
 	if quote == '`' {
 		if strings.Contains(s, "`") {
-			return "", os.EINVAL
+			return "", ErrSyntax
 		}
 		return s, nil
 	}
 	if quote != '"' && quote != '\'' {
-		return "", os.EINVAL
+		return "", ErrSyntax
 	}
 	if strings.Index(s, "\n") >= 0 {
-		return "", os.EINVAL
+		return "", ErrSyntax
 	}
 
 	// Is it trivial?  Avoid allocation.
@@ -319,7 +319,7 @@ func Unquote(s string) (t string, err os.Error) {
 		}
 		if quote == '\'' && len(s) != 0 {
 			// single-quoted must be single character
-			return "", os.EINVAL
+			return "", ErrSyntax
 		}
 	}
 	return buf.String(), nil

src/pkg/strconv/quote_test.go

@@ -5,7 +5,6 @@
 package strconv_test
 
 import (
-	"os"
 	. "strconv"
 	"testing"
 )
@@ -210,8 +209,8 @@ func TestUnquote(t *testing.T) {
 	}
 
 	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)
+		if out, err := Unquote(s); out != "" || err != ErrSyntax {
+			t.Errorf("Unquote(%#q) = %q, %v want %q, %v", s, out, err, "", ErrSyntax)
 		}
 	}
 }