Merge pull request #3094 from ruby/for-loop-require-delimiter

Require a for loop delimiter

config.yml

@@ -99,6 +99,7 @@ errors:
   - EXPECT_EXPRESSION_AFTER_SPLAT
   - EXPECT_EXPRESSION_AFTER_SPLAT_HASH
   - EXPECT_EXPRESSION_AFTER_STAR
+  - EXPECT_FOR_DELIMITER
   - EXPECT_IDENT_REQ_PARAMETER
   - EXPECT_IN_DELIMITER
   - EXPECT_LPAREN_REQ_PARAMETER

src/prism.c

@@ -19452,10 +19452,11 @@ parse_expression_prefix(pm_parser_t *parser, pm_binding_power_t binding_power, b
                 do_keyword = parser->previous;
             } else {
                 do_keyword = not_provided(parser);
+                if (!match2(parser, PM_TOKEN_SEMICOLON, PM_TOKEN_NEWLINE)) {
+                    PM_PARSER_ERR_TOKEN_FORMAT(parser, parser->current, PM_ERR_EXPECT_FOR_DELIMITER, pm_token_type_human(parser->current.type));
+                }
             }
 
-            accept2(parser, PM_TOKEN_SEMICOLON, PM_TOKEN_NEWLINE);
-
             pm_statements_node_t *statements = NULL;
             if (!match1(parser, PM_TOKEN_KEYWORD_END)) {
                 statements = parse_statements(parser, PM_CONTEXT_FOR, (uint16_t) (depth + 1));

templates/src/diagnostic.c.erb

@@ -182,6 +182,7 @@ static const pm_diagnostic_data_t diagnostic_messages[PM_DIAGNOSTIC_ID_MAX] = {
     [PM_ERR_EXPECT_EXPRESSION_AFTER_SPLAT]      = { "expected an expression after `*` splat in an argument", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_EXPECT_EXPRESSION_AFTER_SPLAT_HASH] = { "expected an expression after `**` in a hash", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_EXPECT_EXPRESSION_AFTER_STAR]       = { "expected an expression after `*`", PM_ERROR_LEVEL_SYNTAX },
+    [PM_ERR_EXPECT_FOR_DELIMITER]               = { "unexpected %s; expected a 'do', newline, or ';' after the 'for' loop collection", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_EXPECT_IDENT_REQ_PARAMETER]         = { "expected an identifier for the required parameter", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_EXPECT_IN_DELIMITER]                = { "expected a delimiter after the patterns of an `in` clause", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_EXPECT_LPAREN_REQ_PARAMETER]        = { "expected a `(` to start a required parameter", PM_ERROR_LEVEL_SYNTAX },

test/prism/errors/for_loop_delimiter.txt

@@ -0,0 +1,3 @@
+for a in b end
+           ^~~ unexpected 'end'; expected a 'do', newline, or ';' after the 'for' loop collection
+

test/prism/errors/for_loops_only_end.txt

@@ -2,4 +2,5 @@ for end
 ^~~ expected an index after `for`
    ^ expected an `in` after the index in a `for` statement
    ^ expected a collection after the `in` in a `for` statement
+    ^~~ unexpected 'end'; expected a 'do', newline, or ';' after the 'for' loop collection