Ignore newlines in labelled lambda arguments

Author: haldun

src/prism.c

@@ -14460,6 +14460,7 @@ parse_parameters(
     bool allows_trailing_comma,
     bool allows_forwarding_parameters,
     bool accepts_blocks_in_defaults,
+    bool in_block,
     uint16_t depth
 ) {
     pm_do_loop_stack_push(parser, false);
@@ -14624,7 +14625,7 @@ parse_parameters(
                 break;
             }
             case PM_TOKEN_LABEL: {
-                if (!uses_parentheses) parser->in_keyword_arg = true;
+                if (!uses_parentheses && !in_block) parser->in_keyword_arg = true;
                 update_parameter_state(parser, &parser->current, &order);
 
                 context_push(parser, PM_CONTEXT_DEFAULT_PARAMS);
@@ -15188,6 +15189,7 @@ parse_block_parameters(
             allows_trailing_comma,
             false,
             accepts_blocks_in_defaults,
+            true,
             (uint16_t) (depth + 1)
         );
     }
@@ -19341,7 +19343,7 @@ parse_expression_prefix(pm_parser_t *parser, pm_binding_power_t binding_power, b
                     if (match1(parser, PM_TOKEN_PARENTHESIS_RIGHT)) {
                         params = NULL;
                     } else {
-                        params = parse_parameters(parser, PM_BINDING_POWER_DEFINED, true, false, true, true, (uint16_t) (depth + 1));
+                        params = parse_parameters(parser, PM_BINDING_POWER_DEFINED, true, false, true, true, false, (uint16_t) (depth + 1));
                     }
 
                     lex_state_set(parser, PM_LEX_STATE_BEG);
@@ -19366,7 +19368,7 @@ parse_expression_prefix(pm_parser_t *parser, pm_binding_power_t binding_power, b
 
                     lparen = not_provided(parser);
                     rparen = not_provided(parser);
-                    params = parse_parameters(parser, PM_BINDING_POWER_DEFINED, false, false, true, true, (uint16_t) (depth + 1));
+                    params = parse_parameters(parser, PM_BINDING_POWER_DEFINED, false, false, true, true, false, (uint16_t) (depth + 1));
 
                     context_pop(parser);
                     break;

test/prism/fixtures/lambda.txt

@@ -9,3 +9,15 @@
 -> foo = bar do end
 
 -> foo: bar do end
+
+p{|a:
+b|}
+
+->(a:
+b){}
+
+->a:
+b{}
+
+->a:
+{}