diff options
| -rw-r--r-- | Grammar/python.gram | 2 | ||||
| -rw-r--r-- | Lib/test/test_named_expressions.py | 9 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Core and Builtins/2020-11-16-17-57-09.bpo-42374.t7np1E.rst | 2 | ||||
| -rw-r--r-- | Parser/pegen/parse.c | 12 |
4 files changed, 18 insertions, 7 deletions
diff --git a/Grammar/python.gram b/Grammar/python.gram index 60eeb36..257d2f5 100644 --- a/Grammar/python.gram +++ b/Grammar/python.gram @@ -503,7 +503,7 @@ group[expr_ty]: | '(' a=(yield_expr | named_expression) ')' { a } | invalid_group genexp[expr_ty]: - | '(' a=expression ~ b=for_if_clauses ')' { _Py_GeneratorExp(a, b, EXTRA) } + | '(' a=named_expression ~ b=for_if_clauses ')' { _Py_GeneratorExp(a, b, EXTRA) } | invalid_comprehension set[expr_ty]: '{' a=expressions_list '}' { _Py_Set(a, EXTRA) } setcomp[expr_ty]: diff --git a/Lib/test/test_named_expressions.py b/Lib/test/test_named_expressions.py index c813830..d614f32 100644 --- a/Lib/test/test_named_expressions.py +++ b/Lib/test/test_named_expressions.py @@ -513,6 +513,15 @@ spam()""" self.assertEqual(nonlocal_var, None) f() + def test_named_expression_scope_in_genexp(self): + a = 1 + b = [1, 2, 3, 4] + genexp = (c := i + a for i in b) + + self.assertNotIn("c", locals()) + for idx, elem in enumerate(genexp): + self.assertEqual(elem, b[idx] + a) + if __name__ == "__main__": unittest.main() diff --git a/Misc/NEWS.d/next/Core and Builtins/2020-11-16-17-57-09.bpo-42374.t7np1E.rst b/Misc/NEWS.d/next/Core and Builtins/2020-11-16-17-57-09.bpo-42374.t7np1E.rst new file mode 100644 index 0000000..d86d038 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2020-11-16-17-57-09.bpo-42374.t7np1E.rst @@ -0,0 +1,2 @@ +Fix a regression introduced by the new parser, where an unparenthesized walrus operator
+was not allowed within generator expressions.
\ No newline at end of file diff --git a/Parser/pegen/parse.c b/Parser/pegen/parse.c index 97cefa9..c78abfa 100644 --- a/Parser/pegen/parse.c +++ b/Parser/pegen/parse.c @@ -11381,7 +11381,7 @@ group_rule(Parser *p) return _res; } -// genexp: '(' expression ~ for_if_clauses ')' | invalid_comprehension +// genexp: '(' named_expression ~ for_if_clauses ')' | invalid_comprehension static expr_ty genexp_rule(Parser *p) { @@ -11401,12 +11401,12 @@ genexp_rule(Parser *p) UNUSED(_start_lineno); // Only used by EXTRA macro int _start_col_offset = p->tokens[_mark]->col_offset; UNUSED(_start_col_offset); // Only used by EXTRA macro - { // '(' expression ~ for_if_clauses ')' + { // '(' named_expression ~ for_if_clauses ')' if (p->error_indicator) { D(p->level--); return NULL; } - D(fprintf(stderr, "%*c> genexp[%d-%d]: %s\n", p->level, ' ', _mark, p->mark, "'(' expression ~ for_if_clauses ')'")); + D(fprintf(stderr, "%*c> genexp[%d-%d]: %s\n", p->level, ' ', _mark, p->mark, "'(' named_expression ~ for_if_clauses ')'")); int _cut_var = 0; Token * _literal; Token * _literal_1; @@ -11415,7 +11415,7 @@ genexp_rule(Parser *p) if ( (_literal = _PyPegen_expect_token(p, 7)) // token='(' && - (a = expression_rule(p)) // expression + (a = named_expression_rule(p)) // named_expression && (_cut_var = 1) && @@ -11424,7 +11424,7 @@ genexp_rule(Parser *p) (_literal_1 = _PyPegen_expect_token(p, 8)) // token=')' ) { - D(fprintf(stderr, "%*c+ genexp[%d-%d]: %s succeeded!\n", p->level, ' ', _mark, p->mark, "'(' expression ~ for_if_clauses ')'")); + D(fprintf(stderr, "%*c+ genexp[%d-%d]: %s succeeded!\n", p->level, ' ', _mark, p->mark, "'(' named_expression ~ for_if_clauses ')'")); Token *_token = _PyPegen_get_last_nonnwhitespace_token(p); if (_token == NULL) { D(p->level--); @@ -11444,7 +11444,7 @@ genexp_rule(Parser *p) } p->mark = _mark; D(fprintf(stderr, "%*c%s genexp[%d-%d]: %s failed!\n", p->level, ' ', - p->error_indicator ? "ERROR!" : "-", _mark, p->mark, "'(' expression ~ for_if_clauses ')'")); + p->error_indicator ? "ERROR!" : "-", _mark, p->mark, "'(' named_expression ~ for_if_clauses ')'")); if (_cut_var) { D(p->level--); return NULL; |