[GROOVY-11013] Fail to substitute type when having SAM type with generics

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 3.0.18, 4.0.13
• Component/s: Static Type Checker
• Assignee: Eric Milles
• Reporter: Thodoris Sotiropoulos
• Created: 14/Apr/23 14:09
• Updated: 23/Aug/23 09:05
• Resolved: 26/May/23 21:09

Description

I have the following program

import java.util.*;

@FunctionalInterface
interface Foo<T> {
  int m(List<T> x);
}

class Main {
  static final void test() {
    Foo<String> p = (List<String> x) -> 1;
  }
}

Actual behavior

org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
Main.groovy: 11: [Static type checking] - Expected type java.util.List<T> for lambda parameter: x
 @ line 11, column 22.
       Foo<String> p = (List<String> x) -> 1;
                        ^

1 error

Expected behavior

Compile successfully

Notes

Tested against master (commit: cdc57551a7cce33ec7031b40753f25c869dcf0cc)

Test case adapted from the following program that uses the apache-commons-collection4 lib

class Main {
  static final void test() {
    org.apache.commons.collections4.sequence.ReplacementsHandler<Number> f = (int x, List<java.io.IOException> y, List<Number> z) -> { } ;
  }
}

Issue Links

• relates to: GROOVY-11072 Unable to compile: Expected type for closure parameter