Remove One List From Another
The --/2
operator allows you to subtract two lists, that is, remove all elements in the right list from the left list. Each occurrence of an element is removed if there is a corresponding element. If there is no corresponding element, it is ignored.
Here are some examples.
This kind of list operation is not particularly efficient, so for large lists it can be quite slow. The following example took several minutes to run.
To achieve a true set difference, you'll note that the docs for this operator recommend checking out MapSet.difference/2
.
See h Kernel.--
for more details.
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