Posted by tty on Feb 11, 2020; 6:05pm
URL: https://forum.world.st/Does-Set-respect-ordering-tp5111536p5111549.html

The implementation of withoutDuplicates is brilliant.


*withoutDuplicates
        "Answer a copy of the receiver that preserves order but eliminates any
duplicates."
        | seen |
        seen := Set new: self size.
        ^self select: [:each| seen ifAbsentAdd: each]*

The Set acts as a growing "mask" of what is allowed in the OrderedCollection
returned by select.

I have never seen this idiom. Truly inspiring.




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