partition ( ... seq quot: ( ... elt -- ... ? ) -- ... trueseq falseseq )
Factor handbook » The language » Collections » Sequence operations » Sequence combinators

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Vocabulary
sequences

Inputs

seq	a sequence
quot	a quotation

Outputs

trueseq	a sequence
falseseq	a sequence

Word description
Calls a predicate quotation on each element of the input sequence. If the test yields true, the element is added to trueseq; if false, it's added to falseseq.

Examples

USING: prettyprint kernel math sequences ; { 1 2 3 4 5 } [ even? ] partition [ . ] bi@
{ 2 4 } { 1 3 5 }

Definition

USING: kernel ;

IN: sequences

: partition
    ( ... seq quot: ( ... elt -- ... ? ) -- ... trueseq falseseq )
    over [ 2selector [ each ] 2dip ] dip [ like ] curry bi@ ;
    inline