[GROOVY-5744] Multiple assignment from Iterator skips every other element

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0.5
• Fix Version/s: 5.0.0-alpha-1
• Component/s: groovy-runtime
• Assignee: Eric Milles
• Reporter: Justin Piper
• Created: 05/Oct/12 17:54
• Updated: 23/Aug/23 09:11
• Resolved: 10/Oct/22 08:16

Description

If you try to assign multiple variables from an iterator Groovy will skip every other value.

Example:

final list = [1,2,3]
final iter = list.iterator()

final def (a,b,c) = list
final def (d,e,f) = iter

assert "$a $b $c" == "$d $e $f"

Result:

Assertion failed: 

assert "$a $b $c" == "$d $e $f"
         |  |  |  |    |  |  |
         1  2  3  |    1  3  null
                  false

The expected behavior is either that the assertion succeeds, or the assignment to (d,e,f) fails outright.

If this is fixed it would also be nice if any Iterable could be used on the RHS.

Issue Links

• relates to: GROOVY-10666 Implement multiple-assignment (aka destructuring) via getAt(IntRange) or iterator()
• links to: GitHub Pull Request #1756