[GROOVY-11077] STC overconstraints lambda's parameter types when expecting a SAM that involves wildcards

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: Static Type Checker
• Labels: Lambda
• Assignee: Unassigned
• Reporter: Thodoris Sotiropoulos
• Created: 02/Jun/23 14:42
• Updated: 02/Jun/23 14:42

Description

I have the following program

class Test {
  void test() {
    m((Integer x, Integer y) -> 1);
  }

  void m(java.util.Comparator<? extends Object> x) {}
}

Actual behavior

test.groovy: 3: [Static type checking] - Expected type java.lang.Object for lambda parameter: x
 @ line 3, column 8.
       m((Integer x, Integer y) -> 1);
          ^

test.groovy: 3: [Static type checking] - Expected type java.lang.Object for lambda parameter: y
 @ line 3, column 19.
       m((Integer x, Integer y) -> 1);
                     ^

2 errors

Expected behaviour

Compile successfully

Tested against master (commit: 1d9f35a448a2a731499534841ffe64150e80744c)