[GROOVY-2193] Method invocation that returns no value should evaluate to a known constant instead of null

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.1-beta-3
• Component/s: groovy-runtime
• Assignee: Unassigned
• Reporter: Peter Niederwieser
• Created: 11/Oct/07 17:01
• Updated: 27/Nov/13 07:14

Description

Currently, a method invocation that returns no value evaluates to null. But sometimes it's important to know whether the method actually returned a value or not (e.g. DSLs come to mind). Therefore I propose that method invocations that return no value evaluate to a known constant (e.g. Constants.NO_RETURN_VALUE) instead of null. Apart from making the language more consistent, this would fit in nicely with Groovy's dynamic style, where the return type of a method is generally not known at compile time, and a method might only sometimes return a value.

Related discussions on the mailing list:
http://www.nabble.com/Void-the-same-as-null--tf3535287.html#a9867884
http://www.nabble.com/Ways-to-differentiate-between-methods-that-return-nothing%2C-and-methods-that-return-null-tf4574659.html#a13057848