intersect! ( set1 set2 -- set1 )
Factor handbook » The language » Collections » Sets » Operations on sets

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Vocabulary
sets

Inputs

set1	a set
set2	a set

Outputs

set1

a set

Word description
Removes all members from set1 not contained in set2.

Side effects
Modifies set1

Definition

USING: kernel sequences sets.private ;

IN: sets

: intersect! ( set1 set2 -- set1 )
    dupd sequence/tester pick
    '[ dup @ [ drop ] [ _ delete ] if ] each ;