go/scanner: accept 'i' suffix orthogonally on all numbers

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.

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

Change-Id: I0c182bdf58f8fd1f70090e581b3ccb2f5e2e4e79
Reviewed-on: https://go-review.googlesource.com/c/162880
Reviewed-by: Ian Lance Taylor <iant@golang.org>

diff --git a/src/go/scanner/scanner.go b/src/go/scanner/scanner.go
index 9e85d4898a5c0a549e8fe660f3b17fe173bb35f2..00fe2dc0b19fd0b66bbe3fb48d27d1b0d27b972f 100644 (file)
--- a/src/go/scanner/scanner.go
+++ b/src/go/scanner/scanner.go
@@ -472,9 +472,6 @@ func (s *Scanner) scanNumber() (token.Token, string) {
        // suffix 'i'
        if s.ch == 'i' {
                tok = token.IMAG
-               if prefix != 0 && prefix != '0' {
-                       s.error(s.offset, "invalid suffix 'i' on "+litname(prefix))
-               }
                s.next()
        }
 

diff --git a/src/go/scanner/scanner_test.go b/src/go/scanner/scanner_test.go
index 1d6865f198b006740c1faeabb654febd78ee90a4..9d3bbbbb24e8a5db8667e7ba1cf62c9b7db9986d 100644 (file)
--- a/src/go/scanner/scanner_test.go
+++ b/src/go/scanner/scanner_test.go
@@ -927,13 +927,14 @@ func TestNumbers(t *testing.T) {
                {token.INT, "0b0190", "0b0190", "invalid digit '9' in binary literal"},
                {token.INT, "0b01a0", "0b01 a0", ""}, // only accept 0-9
 
-               // binary floats and imaginaries (invalid)
                {token.FLOAT, "0b.", "0b.", "invalid radix point in binary literal"},
                {token.FLOAT, "0b.1", "0b.1", "invalid radix point in binary literal"},
                {token.FLOAT, "0b1.0", "0b1.0", "invalid radix point in binary literal"},
                {token.FLOAT, "0b1e10", "0b1e10", "'e' exponent requires decimal mantissa"},
                {token.FLOAT, "0b1P-1", "0b1P-1", "'P' exponent requires hexadecimal mantissa"},
-               {token.IMAG, "0b10i", "0b10i", "invalid suffix 'i' on binary literal"},
+
+               {token.IMAG, "0b10i", "0b10i", ""},
+               {token.IMAG, "0b10.0i", "0b10.0i", "invalid radix point in binary literal"},
 
                // octals
                {token.INT, "0o0", "0o0", ""},
@@ -945,13 +946,14 @@ func TestNumbers(t *testing.T) {
                {token.INT, "0o1293", "0o1293", "invalid digit '9' in octal literal"},
                {token.INT, "0o12a3", "0o12 a3", ""}, // only accept 0-9
 
-               // octal floats and imaginaries (invalid)
                {token.FLOAT, "0o.", "0o.", "invalid radix point in octal literal"},
                {token.FLOAT, "0o.2", "0o.2", "invalid radix point in octal literal"},
                {token.FLOAT, "0o1.2", "0o1.2", "invalid radix point in octal literal"},
                {token.FLOAT, "0o1E+2", "0o1E+2", "'E' exponent requires decimal mantissa"},
                {token.FLOAT, "0o1p10", "0o1p10", "'p' exponent requires hexadecimal mantissa"},
-               {token.IMAG, "0o10i", "0o10i", "invalid suffix 'i' on octal literal"},
+
+               {token.IMAG, "0o10i", "0o10i", ""},
+               {token.IMAG, "0o10e0i", "0o10e0i", "'e' exponent requires decimal mantissa"},
 
                // 0-octals
                {token.INT, "0", "0", ""},
@@ -969,6 +971,9 @@ func TestNumbers(t *testing.T) {
 
                {token.INT, "1f", "1 f", ""}, // only accept 0-9
 
+               {token.IMAG, "0i", "0i", ""},
+               {token.IMAG, "0678i", "0678i", ""},
+
                // decimal floats
                {token.FLOAT, "0.", "0.", ""},
                {token.FLOAT, "123.", "123.", ""},
@@ -1004,7 +1009,6 @@ func TestNumbers(t *testing.T) {
                {token.FLOAT, "0p0", "0p0", "'p' exponent requires hexadecimal mantissa"},
                {token.FLOAT, "1.0P-1", "1.0P-1", "'P' exponent requires hexadecimal mantissa"},
 
-               // decimal imaginaries
                {token.IMAG, "0.i", "0.i", ""},
                {token.IMAG, ".123i", ".123i", ""},
                {token.IMAG, "123.123i", "123.123i", ""},
@@ -1021,6 +1025,8 @@ func TestNumbers(t *testing.T) {
                {token.INT, "0x", "0x", "hexadecimal literal has no digits"},
                {token.INT, "0x1g", "0x1 g", ""},
 
+               {token.IMAG, "0xf00i", "0xf00i", ""},
+
                // hexadecimal floats
                {token.FLOAT, "0x0p0", "0x0p0", ""},
                {token.FLOAT, "0x12efp-123", "0x12efp-123", ""},
@@ -1039,9 +1045,7 @@ func TestNumbers(t *testing.T) {
                {token.FLOAT, "0x1234PAB", "0x1234P AB", "exponent has no digits"},
                {token.FLOAT, "0x1.2p1a", "0x1.2p1 a", ""},
 
-               // hexadecimal imaginaries (invalid)
-               {token.IMAG, "0xf00i", "0xf00i", "invalid suffix 'i' on hexadecimal literal"},
-               {token.IMAG, "0xf00.bap+12i", "0xf00.bap+12i", "invalid suffix 'i' on hexadecimal literal"},
+               {token.IMAG, "0xf00.bap+12i", "0xf00.bap+12i", ""},
 
                // separators
                {token.INT, "0b_1000_0001", "0b_1000_0001", ""},