interleave ( ... seq between quot: ( ... elt -- ... ) -- ... )
Factor handbook » The language » Collections » Sequence operations » Sequence combinators

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Vocabulary
sequences

Inputs

seq	a sequence
between	a quotation
quot	a quotation with stack effect ( ... elt -- ... )

Outputs
None

Word description
Applies quot to each element in turn, also invoking between in-between each pair of elements.

Examples

USING: io sequences ; { "a" "b" "c" } [ "X" write ] [ write ] interleave
aXbXc

Definition

USING: kernel sequences.private ;

IN: sequences

: interleave
    ( ... seq between quot: ( ... elt -- ... ) -- ... )
    pick empty?
    [ 3drop ] [
        [ [ drop first-unsafe ] dip call ]
        [ [ bi* ] 2curry 1 each-from ] 3bi
    ] if ; inline