Enable pattern matching by default (#2758)

[etc/vim.git] / src / blib2to3 / Grammar.txt

diff --git a/src/blib2to3/Grammar.txt b/src/blib2to3/Grammar.txt
index 49680323d8b8fe83c98bee1940ee4e1d1e1f94d1..cf4799f8abe860acff10cb1c0fe84ec5130a3b77 100644 (file)
--- a/src/blib2to3/Grammar.txt
+++ b/src/blib2to3/Grammar.txt
@@ -168,8 +168,8 @@ subscript: test [':=' test] | [test] ':' [test] [sliceop]
 sliceop: ':' [test]
 exprlist: (expr|star_expr) (',' (expr|star_expr))* [',']
 testlist: test (',' test)* [',']
-dictsetmaker: ( ((test ':' test | '**' expr)
-                 (comp_for | (',' (test ':' test | '**' expr))* [','])) |
+dictsetmaker: ( ((test ':' asexpr_test | '**' expr)
+                 (comp_for | (',' (test ':' asexpr_test | '**' expr))* [','])) |
                 ((test [':=' test] | star_expr)
                 (comp_for | (',' (test [':=' test] | star_expr))* [','])) )
 
@@ -186,7 +186,8 @@ arglist: argument (',' argument)* [',']
 # that precede iterable unpackings are blocked; etc.
 argument: ( test [comp_for] |
             test ':=' test |
-            test '=' test |
+            test 'as' test |
+            test '=' asexpr_test |
            '**' test |
             '*' test )
 
@@ -237,10 +238,14 @@ yield_arg: 'from' test | testlist_star_expr
 # to reformat them.
 
 match_stmt: "match" subject_expr ':' NEWLINE INDENT case_block+ DEDENT
-subject_expr: namedexpr_test
+
+# This is more permissive than the actual version. For example it
+# accepts `match *something:`, even though single-item starred expressions
+# are forbidden.
+subject_expr: (namedexpr_test|star_expr) (',' (namedexpr_test|star_expr))* [',']
 
 # cases
 case_block: "case" patterns [guard] ':' suite
 guard: 'if' namedexpr_test
-patterns: pattern ['as' pattern]
-pattern: (expr|star_expr) (',' (expr|star_expr))* [',']
+patterns: pattern (',' pattern)* [',']
+pattern: (expr|star_expr) ['as' expr]