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https://issues.apache.org/jira/browse/GROOVY-10964?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17701076#comment-17701076
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Paul King commented on GROOVY-10964:
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[~iwilms] I created a PR with your changes and a few tweaks. The hybrid above
is faster for the case where the remove iterable is large and the original
small but the simple size comparison as shown above is too simplistic and I
can't see an easy heuristic that works well for the examples I tried, so I have
gone back to almost your code with a few minor tweaks.
> List.minus() slow for Numbers
> -----------------------------
>
> Key: GROOVY-10964
> URL: https://issues.apache.org/jira/browse/GROOVY-10964
> Project: Groovy
> Issue Type: Question
> Components: groovy-jdk
> Affects Versions: 2.4.0, 3.0.9, 4.0.9
> Reporter: Ingo Wilms
> Priority: Minor
> Labels: Collections, Groovy, List, Number
> Original Estimate: 1h
> Remaining Estimate: 1h
>
> In List.minus() is a n*LOG\(n) version for comparable objects. Only for
> numbers, there is a dedicated slower n^2*LOG\(n) version. Is there a reason
> for this? It exists since 2.4.0 and hasn't changed much since then. Here is
> part of the code from version 4.0.9:
>
> {code:java}
> // if (nlgnSort && (head instanceof Comparable)) {
> //n*LOG(n) version
> Set<T> answer;
> if (head instanceof Number) {
> answer = new TreeSet<>(comparator);
> answer.addAll(self1);
> for (T t : self1) {
> if (t instanceof Number) {
> for (Object t2 : removeMe1) {
> if (t2 instanceof Number) {
> if (comparator.compare(t, (T) t2) == 0)
> answer.remove(t);
> }
> }
> } else {
> if (removeMe1.contains(t))
> answer.remove(t);
> }
> }
> } else {
> answer = new TreeSet<>(comparator);
> answer.addAll(self1);
> answer.removeAll(removeMe1);
> }
> for (T o : self1) {
> if (answer.contains(o))
> ansCollection.add(o);
> }
> } else {
> //n*n version {code}
> I fail to see why the whole extra block for numbers beginning with
> {code:java}
> if (head instanceof Number) { {code}
> is necessary.
>
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