[Python-checkins] cpython (3.4): allow the keyword else immediately after (no space) an integer (closes #21642)

Sat Jun 7 21:40:02 CEST 2014

http://hg.python.org/cpython/rev/4ad33d82193d
changeset: 91061:4ad33d82193d
branch: 3.4
parent: 91059:d23cea976f46
user: Benjamin Peterson <benjamin at python.org>
date: Sat Jun 07 12:36:39 2014 -0700
summary:
 allow the keyword else immediately after (no space) an integer (closes #21642)
files:
 Lib/test/test_grammar.py | 6 ++++++
 Misc/NEWS | 4 ++++
 Parser/tokenizer.c | 19 ++++++++++++++-----
 3 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py
--- a/Lib/test/test_grammar.py
+++ b/Lib/test/test_grammar.py
@@ -80,6 +80,12 @@
 x = .3e14
 x = 3.1e4
 
+ def test_float_exponent_tokenization(self):
+ # See issue 21642.
+ self.assertEqual(1 if 1else 0, 1)
+ self.assertEqual(1 if 0else 0, 0)
+ self.assertRaises(SyntaxError, eval, "0 if 1Else 0")
+
 def test_string_literals(self):
 x = ''; y = ""; self.assertTrue(len(x) == 0 and x == y)
 x = '\''; y = "'"; self.assertTrue(len(x) == 1 and x == y and ord(x) == 39)
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,10 @@
 Core and Builtins
 -----------------
 
+- Issue #21642: If the conditional if-else expression, allow an integer written
+ with no space between itself and the ``else`` keyword (e.g. ``True if 42else
+ False``) to be valid syntax.
+
 - Issue #21523: Fix over-pessimistic computation of the stack effect of
 some opcodes in the compiler. This also fixes a quadratic compilation
 time issue noticeable when compiling code with a large number of "and"
diff --git a/Parser/tokenizer.c b/Parser/tokenizer.c
--- a/Parser/tokenizer.c
+++ b/Parser/tokenizer.c
@@ -1597,15 +1597,24 @@
 } while (isdigit(c));
 }
 if (c == 'e' || c == 'E') {
- exponent:
+ int e;
+ exponent:
+ e = c;
 /* Exponent part */
 c = tok_nextc(tok);
- if (c == '+' || c == '-')
+ if (c == '+' || c == '-') {
 c = tok_nextc(tok);
- if (!isdigit(c)) {
- tok->done = E_TOKEN;
+ if (!isdigit(c)) {
+ tok->done = E_TOKEN;
+ tok_backup(tok, c);
+ return ERRORTOKEN;
+ }
+ } else if (!isdigit(c)) {
 tok_backup(tok, c);
- return ERRORTOKEN;
+ tok_backup(tok, e);
+ *p_start = tok->start;
+ *p_end = tok->cur;
+ return NUMBER;
 }
 do {
 c = tok_nextc(tok);
-- 
Repository URL: http://hg.python.org/cpython
