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Paul King commented on GROOVY-4606: ----------------------------------- Given that we now have methods like {{DGM#toUnique(List, Comparator)}} and you can use {{Comparator.naturalOrder()}} to avoid coercion, should we close this issue or apply it as a small performance boost when using {{unique}}? I think it would belong inside the private {{uniqueItems}} method these days. > Exteremely bad performance of .unique() and .unique {closure} > ------------------------------------------------------------- > > Key: GROOVY-4606 > URL: https://issues.apache.org/jira/browse/GROOVY-4606 > Project: Groovy > Issue Type: Bug > Components: groovy-jdk > Affects Versions: 1.7.5 > Reporter: Maxym Mykhalchuk > Priority: Major > Attachments: UniqueMath.java > > > DefaultGroovyMethods.unique has two inner loops, so its complexity is O(n^2) > Practically it means that it starts taking ages on collections with 1000 or > more elements. > Simply adding elements to a linked hash set would get O(n*log n) performance. > Will develop my own unique implementation after New Year, and will attach it > here -- This message was sent by Atlassian JIRA (v7.6.3#76005)