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https://issues.apache.org/jira/browse/GROOVY-10964?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17700536#comment-17700536
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Jochen Theodorou commented on GROOVY-10964:
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My suggestion would be to rework that code a bit right now if the elements in
the list are the same and not number, then we do the better variant. So why not
if the numbers are all of the same type in the list? That is not a general
solution, but a solution to many cases I think
> 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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