[GROOVY-8271] Take/TakeRight methods on iterator needlessly calls hasNext for one too many elements

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.4.12
• Fix Version/s: 2.4.13
• Component/s: groovy-jdk
• Assignee: Paul King
• Reporter: Marty Neal
• Created: 27/Jul/17 11:49
• Updated: 06/Mar/18 23:25
• Resolved: 01/Aug/17 05:34

Description

I expect the TakeIterator to only call the hasNext() method for the delegate a maximum of N times where N is the number of elements to take. If the iterator represents some expensive operations, or an unexhausted infinite stream that has exactly N elements available, the TakeIterator will block waiting for the Nth+1 element only to return N of them.

In short, change the TakeIterator's hasNext function from

return delegate.hasNext() && num > 0;
to

return num > 0 && delegate.hasNext();

Issue Links

• links to: GitHub Pull Request #578