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https://issues.apache.org/jira/browse/GROOVY-10666?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17573111#comment-17573111
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Eric Milles commented on GROOVY-10666:
--------------------------------------
Here is one case that fails with this approach:
{code:groovy}
def opt = Optional.empty()
def (String s) = opt
assert s == null
opt = Optional.of('')
(s) = opt
assert s == ''
{code}
> Implement multiple-assignment (aka destructuring) via getAt(IntRange) or
> iterator()
> -----------------------------------------------------------------------------------
>
> Key: GROOVY-10666
> URL: https://issues.apache.org/jira/browse/GROOVY-10666
> Project: Groovy
> Issue Type: Improvement
> Components: bytecode, groovy-jdk
> Reporter: Eric Milles
> Assignee: Eric Milles
> Priority: Minor
>
> Currently multiple-assignment is implemented using {{getAt(int)}}. For types
> that support {{getAt(IntRange)}} it may be more efficient to use that
> operation. For cases where {{getAt(int)}} is a terminal operation (aka
> streams) it may be the only way to go. Or maybe using one {{iterator()}}
> would be better overall.
> Consider the following:
> {code:groovy}
> Set<String> set = ['foo','bar','baz']
> def (foo, bar, baz) = set // inefficient; requires 3 iterators and 6 calls to
> next
> Stream<String> stream = ['foo','bar','baz'].stream()
> def (foo, bar, baz) = stream // not possible because `getAt(int)` is terminal
> {code}
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