[GROOVY-8276] `.&` should return `MethodClosure` instead of just `Closure`

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: Compiler
• Assignee: Unassigned
• Reporter: Vladimír Oraný
• Created: 04/Aug/17 10:28
• Updated: 04/Aug/17 16:08

Description

if you get method handle using `.&` notation the retrieved object is of type `Closure`. It should be method closure instead. Following code should compile:

    @CompileStatic
    void doSomething(MethodClosure methodClosure) {
        this.doSomething(this.&doSomething)
    }

One of the use cases I'm currently working on is a type-safe DSL which accepts method closure to test given method. I would like to be sure that none passes in regular closure. At the moment, I need to do

        if (!(method instanceof MethodClosure)) {
            throw new IllegalArgumentException("Closure must be method closure. Use object.&methodname to get type safe method closure!")
        }

To achieve similar behavior.