Merge pull request #1557 from haldun/haldun/reject-numbered-parameter

Reject numbered parameters in block parameters

src/yarp.c

@@ -4814,10 +4814,20 @@ yp_parser_local_add_owned(yp_parser_t *parser, const uint8_t *start, size_t leng
     if (constant_id != 0) yp_parser_local_add(parser, constant_id);
 }
 
+static inline bool
+token_is_numbered_parameter(const uint8_t *start, const uint8_t *end) {
+    return (end - start == 2) && (start[0] == '_') && (start[1] != '0') && (yp_char_is_decimal_digit(start[1]));
+}
+
 // Add a parameter name to the current scope and check whether the name of the
 // parameter is unique or not.
 static void
 yp_parser_parameter_name_check(yp_parser_t *parser, yp_token_t *name) {
+    // We want to check whether the parameter name is a numbered parameter or not.
+    if (token_is_numbered_parameter(name->start, name->end)) {
+        yp_diagnostic_list_append(&parser->error_list, name->start, name->end, YP_ERR_PARAMETER_NUMBERED_RESERVED);
+    }
+
     // We want to ignore any parameter name that starts with an underscore.
     if ((*name->start == '_')) return;
 
@@ -4898,11 +4908,6 @@ char_is_global_name_punctuation(const uint8_t b) {
     return (yp_global_name_punctuation_hash[(i - 0x20) / 32] >> (i % 32)) & 1;
 }
 
-static inline bool
-token_is_numbered_parameter(const uint8_t *start, const uint8_t *end) {
-    return (end - start == 2) && (start[0] == '_') && (start[1] != '0') && (yp_char_is_decimal_digit(start[1]));
-}
-
 static inline bool
 token_is_setter_name(yp_token_t *token) {
     return (

test/yarp/errors_test.rb

@@ -1302,6 +1302,13 @@ def test_alnum_delimiters
       assert_error_messages "%sXfooX", error_messages
     end
 
+    def test_numbered_parameters_in_block_arguments
+      source = "foo { |_1| }"
+      assert_errors expression(source), source, [
+        ["Token reserved for a numbered parameter", 7..9],
+      ]
+    end
+
     def test_conditional_predicate_closed
       source = "if 0 0; end\nunless 0 0; end"
       assert_errors expression(source), source, [