[GROOVY-6336] [PARROT] Support Java 7 ARM blocks

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.2.0-beta-2
• Fix Version/s: 3.0.0-alpha-1, 2.6.0-alpha-1
• Component/s: Compiler
• Epic Link: PARROT
• Assignee: Daniel Sun
• Reporter: Tom Dunstan
• Created: 09/Sep/13 21:16
• Updated: 20/May/19 07:15
• Resolved: 02/May/17 02:12

Description

Currently Groovy does not have an equivalent to Java 7's ARM blocks. The closest is adding a method which takes a closure to the class that you'd like to be auto-closed (or whatever gives you that resource), and implementing the closing logic in that method. This has a host of problems:

• It's inefficient, requiring multiple method calls and an extra closure class over the Java solution

• Since the closure-accepting methods are added ad-hoc, they have different names and quite possibly subtly different behaviour, particularly around what happens if an exception is thrown during the closing. By contrast this is well defined in Java 7 so a programmer doesn't have to go hunting for documentation or source code on the method that they're calling

• If you are trying to work with an existing Java library rather than Groovy code, you're out of luck, since short of metaclass hacking you won't be able to add a wrapper method anyway

It would also be nice to keep Groovy and Java syntax as consistent as possible to ease porting between the two.

Issue Links

• Dependency: GROOVY-8586 [PARROT] Support Java 9 ARM blocks