IN: delimited-continuations

USING: kernel continuations namespaces locals sequences accessors fry math ;

SYMBOL: Holes

: hole-init ( -- )
    V{ } clone Holes set ;
: hole-push ( hole -- )
    Holes get push ;
: hole-pop ( -- hole )
    Holes get pop ;

: abort-top ( v -- * )
    hole-pop continue-with ;

: set-top ( quot -- obj )
    '[ hole-push @ ] callcc1 ; inline

: reset ( quot -- obj )
    '[ @ abort-top ] set-top ; inline

:: shift ( quot -- obj )
     [| k |
       [| x | [ x k continue-with ] set-top ]
       quot call abort-top
     ] callcc1
    ; inline