Issue #27985: Implement PEP 526 -- Syntax for Variable Annotations.
Patch by Ivan Levkivskyi.
diff --git a/Lib/lib2to3/Grammar.txt b/Lib/lib2to3/Grammar.txt
index c954669..abe1268 100644
--- a/Lib/lib2to3/Grammar.txt
+++ b/Lib/lib2to3/Grammar.txt
@@ -54,12 +54,13 @@
simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
small_stmt: (expr_stmt | print_stmt | del_stmt | pass_stmt | flow_stmt |
import_stmt | global_stmt | exec_stmt | assert_stmt)
-expr_stmt: testlist_star_expr (augassign (yield_expr|testlist) |
+expr_stmt: testlist_star_expr (annassign | augassign (yield_expr|testlist) |
('=' (yield_expr|testlist_star_expr))*)
+annassign: ':' test ['=' test]
testlist_star_expr: (test|star_expr) (',' (test|star_expr))* [',']
augassign: ('+=' | '-=' | '*=' | '@=' | '/=' | '%=' | '&=' | '|=' | '^=' |
'<<=' | '>>=' | '**=' | '//=')
-# For normal assignments, additional restrictions enforced by the interpreter
+# For normal and annotated assignments, additional restrictions enforced by the interpreter
print_stmt: 'print' ( [ test (',' test)* [','] ] |
'>>' test [ (',' test)+ [','] ] )
del_stmt: 'del' exprlist