[GROOVY-740] Closures can't modify variables more than 1 lexical level up

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0-beta-9
• Fix Version/s: 1.0-beta-10
• Environment: windows xp + cygwin, sun jdk 1.5.0_01-b08
• Assignee: Unassigned
• Reporter: Steve Yegge
• Created: 18/Feb/05 02:52
• Updated: 05/Mar/05 05:00
• Resolved: 05/Mar/05 05:00

Description

This small test script illustrates the problem:

1. begin script
   def ctest()
   Unknown macro: { a = -1 cl1 = { a = 2 }
   cl1()
   println "a is now: ${a}"
   
   a = -1
   cl2 = {
   cl3 = { a = 2 } cl3() }

   cl2()
   println "a is now: ${a}"
   }

ctest()

1. end script

Running the code above produces:

a is now: 2
a is now: -1

It should have changed a to 2 both times. It may be non-obvious
from this trivial test script, but the situation occurs frequently
enough to be a significant obstacle to development. Workaround is
to refactor code so that it never has more than one nesting level.