(sierpinski) ( triangle spaces n -- triangle' )

Vocabulary

rosetta-code.sierpinski-triangle

Inputs

triangle	an object
spaces	an object
n	an object

Outputs

triangle'

an object

Definition

USING: kernel math sequences splitting ;

IN: rosetta-code.sierpinski-triangle

: (sierpinski) ( triangle spaces n -- triangle' )
    dup 0 =
    [ 2drop join-lines ] [
        [ [ iterate-triangle ] [ nip dup append ] 2bi ] dip 1 -
        (sierpinski)
    ] if ;