[GROOVY-11275] Support type witness in method reference

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 4.0.17
• Component/s: Compiler, parser-antlr4
• Assignee: Unassigned
• Reporter: Christopher Smith
• Created: 09/Jan/24 18:27
• Updated: 11/Jan/24 23:14
• Resolved: 11/Jan/24 23:14

Description

Java permits type witnesses as part of a method reference to provide the usual hinting:

Optional<List<Number>> foo = Optional.of(42).map(List::<Number>of);

The Groovy grammar as of 4.0.17 does not support type witnesses in this position, but there are a number of cases where the compiler (particularly the STC) has limitations with type inference and it would be helpful to have.