Merge pull request #66 from lolengine/fix-lua-backtracking

Reduce backtracking in Lua “for” statement parsing.
taocpp · Aug 4, 2017 · bc56a60 · bc56a60
2 parents fec6fbe + 5e63cff
commit bc56a60
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/src/example/pegtl/lua53_parse.cpp b/src/example/pegtl/lua53_parse.cpp
@@ -300,9 +300,9 @@ namespace lua53
    struct else_statement : pegtl::if_must< key_else, statement_list< key_end > > {};
    struct if_statement : pegtl::if_must< key_if, seps, expression, seps, key_then, statement_list< at_elseif_else_end >, seps, pegtl::until< pegtl::sor< else_statement, key_end >, elseif_statement, seps > > {};
 
-   struct for_statement_one : pegtl::seq< name, seps, pegtl::one< '=' >, seps, expression, seps, pegtl::one< ',' >, seps, expression, pegtl::pad_opt< pegtl::if_must< pegtl::one< ',' >, seps, expression >, sep >, key_do, statement_list< key_end > > {};
-   struct for_statement_two : pegtl::seq< name_list_must, seps, key_in, seps, expr_list_must, seps, key_do, statement_list< key_end > > {};
-   struct for_statement : pegtl::if_must< key_for, seps, pegtl::sor< for_statement_one, for_statement_two > > {};
+   struct for_statement_one : pegtl::seq< pegtl::one< '=' >, seps, expression, seps, pegtl::one< ',' >, seps, expression, pegtl::pad_opt< pegtl::if_must< pegtl::one< ',' >, seps, expression >, sep > > {};
+   struct for_statement_two : pegtl::seq< pegtl::opt< pegtl::if_must< pegtl::one< ',' >, seps, name_list_must, seps > >, key_in, seps, expr_list_must, seps > {};
+   struct for_statement : pegtl::if_must< key_for, seps, name, seps, pegtl::sor< for_statement_one, for_statement_two >, key_do, statement_list< key_end > > {};
 
    struct assignment_variable_list : pegtl::list_must< variable, pegtl::one< ',' >, sep > {};
    struct assignments_one : pegtl::if_must< pegtl::one< '=' >, seps, expr_list_must > {};