checkpoint ( quot -- quot' )

Vocabulary

backtrack

Inputs

quot

an object

Outputs

quot'

an object

Definition

USING: continuations kernel namespaces ;

IN: backtrack

MACRO: checkpoint ( quot -- quot' )
    [ [ failure get ] ] dip [
        [
            [
                [
                    [ ~quotation~ ] dip [ continue ] curry
                    compose callcc0
                ]
            ] dip [ failure set ] curry compose
        ] dip compose callcc0
    ] curry compose ;