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cmd/compile: accept 'i' suffix orthogonally on all numbers

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This change accepts the 'i' suffix on binary and octal integer
literals as well as hexadecimal floats. The suffix was already
accepted on decimal integers and floats.

Note that 0123i == 123i for backward-compatibility (and 09i is
valid).

See also the respective language in the spec change:
https://golang.org/cl/161098

Change-Id: I9d2d755cba36a3fa7b9e24308c73754d4568daaf
Reviewed-on: https://go-review.googlesource.com/c/162878
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This commit is contained in:
Robert Griesemer 2019-02-14 17:34:29 -08:00
parent c3b49186a6
commit 4ad5537bfa
5 changed files with 58 additions and 34 deletions
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28
src/cmd/compile/internal/gc/mpfloat.go
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@ -183,15 +183,33 @@ func (a *Mpflt) SetString(as string) {
// TODO(gri) remove this code once math/big.Float.Parse can handle separators
as = strings.Replace(as, "_", "", -1) // strip separators
// TODO(gri) why is this needed?
for len(as) > 0 && (as[0] == ' ' || as[0] == '\t') {
as = as[1:]
}
f, _, err := a.Val.Parse(as, 0)
if err != nil {
yyerror("malformed constant: %s (%v)", as, err)
a.Val.SetFloat64(0)
return
// Currently, Val.Parse below (== math/big.Float.Parse) does not
// handle the 0o-octal prefix which can appear with octal integers
// with 'i' suffix, which end up here as imaginary components of
// complex numbers. Handle explicitly for now.
// TODO(gri) remove once Float.Parse can handle octals (it handles 0b/0B)
var f *big.Float
if strings.HasPrefix(as, "0o") || strings.HasPrefix(as, "0O") {
x, ok := new(big.Int).SetString(as[2:], 8)
if !ok {
yyerror("malformed constant: %s", as)
a.Val.SetFloat64(0)
return
}
f = a.Val.SetInt(x)
} else {
var err error
f, _, err = a.Val.Parse(as, 0)
if err != nil {
yyerror("malformed constant: %s (%v)", as, err)
a.Val.SetFloat64(0)
return
}
}
if f.IsInf() {

3
src/cmd/compile/internal/syntax/scanner.go
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@ -512,9 +512,6 @@ func (s *scanner) number(c rune) {
// suffix 'i'
if c == 'i' {
s.kind = ImagLit
if prefix != 0 && prefix != '0' {
s.error("invalid suffix 'i' on " + litname(prefix))
}
c = s.getr()
}
s.ungetr()

20
src/cmd/compile/internal/syntax/scanner_test.go
View File

@ -347,13 +347,14 @@ func TestNumbers(t *testing.T) {
{IntLit, "0b0190", "0b0190", "invalid digit '9' in binary literal"},
{IntLit, "0b01a0", "0b01 a0", ""}, // only accept 0-9
// binary floats and imaginaries (invalid)
{FloatLit, "0b.", "0b.", "invalid radix point in binary literal"},
{FloatLit, "0b.1", "0b.1", "invalid radix point in binary literal"},
{FloatLit, "0b1.0", "0b1.0", "invalid radix point in binary literal"},
{FloatLit, "0b1e10", "0b1e10", "'e' exponent requires decimal mantissa"},
{FloatLit, "0b1P-1", "0b1P-1", "'P' exponent requires hexadecimal mantissa"},
{ImagLit, "0b10i", "0b10i", "invalid suffix 'i' on binary literal"},
{ImagLit, "0b10i", "0b10i", ""},
{ImagLit, "0b10.0i", "0b10.0i", "invalid radix point in binary literal"},
// octals
{IntLit, "0o0", "0o0", ""},
@ -365,13 +366,14 @@ func TestNumbers(t *testing.T) {
{IntLit, "0o1293", "0o1293", "invalid digit '9' in octal literal"},
{IntLit, "0o12a3", "0o12 a3", ""}, // only accept 0-9
// octal floats and imaginaries (invalid)
{FloatLit, "0o.", "0o.", "invalid radix point in octal literal"},
{FloatLit, "0o.2", "0o.2", "invalid radix point in octal literal"},
{FloatLit, "0o1.2", "0o1.2", "invalid radix point in octal literal"},
{FloatLit, "0o1E+2", "0o1E+2", "'E' exponent requires decimal mantissa"},
{FloatLit, "0o1p10", "0o1p10", "'p' exponent requires hexadecimal mantissa"},
{ImagLit, "0o10i", "0o10i", "invalid suffix 'i' on octal literal"},
{ImagLit, "0o10i", "0o10i", ""},
{ImagLit, "0o10e0i", "0o10e0i", "'e' exponent requires decimal mantissa"},
// 0-octals
{IntLit, "0", "0", ""},
@ -389,6 +391,9 @@ func TestNumbers(t *testing.T) {
{IntLit, "1f", "1 f", ""}, // only accept 0-9
{ImagLit, "0i", "0i", ""},
{ImagLit, "0678i", "0678i", ""},
// decimal floats
{FloatLit, "0.", "0.", ""},
{FloatLit, "123.", "123.", ""},
@ -424,7 +429,6 @@ func TestNumbers(t *testing.T) {
{FloatLit, "0p0", "0p0", "'p' exponent requires hexadecimal mantissa"},
{FloatLit, "1.0P-1", "1.0P-1", "'P' exponent requires hexadecimal mantissa"},
// decimal imaginaries
{ImagLit, "0.i", "0.i", ""},
{ImagLit, ".123i", ".123i", ""},
{ImagLit, "123.123i", "123.123i", ""},
@ -441,6 +445,8 @@ func TestNumbers(t *testing.T) {
{IntLit, "0x", "0x", "hexadecimal literal has no digits"},
{IntLit, "0x1g", "0x1 g", ""},
{ImagLit, "0xf00i", "0xf00i", ""},
// hexadecimal floats
{FloatLit, "0x0p0", "0x0p0", ""},
{FloatLit, "0x12efp-123", "0x12efp-123", ""},
@ -459,9 +465,7 @@ func TestNumbers(t *testing.T) {
{FloatLit, "0x1234PAB", "0x1234P AB", "exponent has no digits"},
{FloatLit, "0x1.2p1a", "0x1.2p1 a", ""},
// hexadecimal imaginaries (invalid)
{ImagLit, "0xf00i", "0xf00i", "invalid suffix 'i' on hexadecimal literal"},
{ImagLit, "0xf00.bap+12i", "0xf00.bap+12i", "invalid suffix 'i' on hexadecimal literal"},
{ImagLit, "0xf00.bap+12i", "0xf00.bap+12i", ""},
// separators
{IntLit, "0b_1000_0001", "0b_1000_0001", ""},

3
src/cmd/compile/internal/syntax/tokens.go
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@ -92,6 +92,9 @@ func contains(tokset uint64, tok token) bool {
type LitKind uint
// TODO(gri) With the 'i' (imaginary) suffix now permitted on integer
// and floating-point numbers, having a single ImagLit does
// not represent the literal kind well anymore. Remove it?
const (
IntLit LitKind = iota
FloatLit

38
test/literal2.go
View File

@ -5,7 +5,8 @@
// license that can be found in the LICENSE file.
// Test Go2 literal syntax for basic types.
// TODO add more tests
// Avoid running gofmt on this file to preserve the
// test cases with upper-case prefixes (0B, 0O, 0X).
package main
@ -17,7 +18,7 @@ func assert(cond bool) {
}
}
func equal(x, y float64) bool {
func equal(x, y interface{}) bool {
if x != y {
fmt.Printf("%g != %g\n", x, y)
return false
@ -30,24 +31,30 @@ func main() {
assert(0_1 == 01)
assert(012 == 012)
assert(0_1_2 == 012)
assert(0_1_2i == complex(0, 12)) // decimal digits despite leading 0 for backward-compatibility
assert(00089i == complex(0, 89)) // decimal digits despite leading 0 for backward-compatibility
// decimals
assert(1_000_000 == 1000000)
assert(1_000i == complex(0, 1000))
// hexadecimals
assert(0x_1 == 0x1)
assert(0x1_2 == 0x12)
assert(0X_cafe_f00d == 0xcafef00d)
assert(0x_cafe_f00d == 0xcafef00d)
assert(0x_cafei == complex(0, 0xcafe))
// octals
assert(0o_1 == 01)
assert(0o12 == 012)
assert(0O_1_2 == 012)
assert(0o_1_2 == 012)
assert(0o_1_2i == complex(0, 0o12))
// binaries
assert(0b_1 == 1)
assert(0b10 == 2)
assert(0b_1_0 == 2)
assert(0b_1_0i == complex(0, 2))
// decimal floats
assert(0. == 0.0)
@ -55,34 +62,29 @@ func main() {
assert(1_0. == 10.0)
assert(.0_1 == 0.01)
assert(1_0.0_1 == 10.01)
assert(1_0.0_1i == complex(0, 10.01))
assert(0.e1_0 == 0.0e10)
assert(.0e1_0 == 0.0e10)
assert(1_0.e1_0 == 10.0e10)
assert(.0_1e1_0 == 0.01e10)
assert(1_0.0_1e1_0 == 10.01e10)
assert(1_0.0_1e1_0i == complex(0, 10.01e10))
// hexadecimal floats
assert(equal(0x1p-2, 0.25))
assert(equal(0x2.p10, 2048.0))
assert(equal(0x1.Fp+0, 1.9375))
assert(equal(0X.8p-0, 0.5))
assert(equal(0X1FFFP-16, 0.1249847412109375))
assert(equal(0x.8p-0, 0.5))
assert(equal(0x1FFFp-16, 0.1249847412109375))
assert(equal(0x1.fffffffffffffp1023, 1.7976931348623157e308))
assert(equal(0x1.fffffffffffffp1023i, complex(0, 1.7976931348623157e308)))
assert(equal(0x_1p-2, 0.25))
assert(equal(0x2.p1_0, 2048.0))
assert(equal(0x1_0.Fp+0, 16.9375))
assert(equal(0X_0.8p-0, 0.5))
assert(equal(0X_1FF_FP-16, 0.1249847412109375))
assert(equal(0x1.f_ffff_ffff_ffffP1_023, 1.7976931348623157e308))
// imaginaries
assert(0i == complex(0, 0))
assert(09i == complex(0, 9)) // "09i" is a decimal int followed by "i"
assert(1.2e+3i == complex(0, 1.2e+3))
assert(0_0i == complex(0, 0))
assert(0_9i == complex(0, 9)) // "0_9i" is a decimal int followed by "i"
assert(1.2_0e+0_3i == complex(0, 1.2e+3))
assert(equal(0x_0.8p-0, 0.5))
assert(equal(0x_1FF_Fp-16, 0.1249847412109375))
assert(equal(0x1.f_ffff_ffff_ffffp1_023, 1.7976931348623157e308))
assert(equal(0x1.f_ffff_ffff_ffffp1_023i, complex(0, 1.7976931348623157e308)))
}