factor/library/continuations.factor

77 lines
1.9 KiB
Factor

! Copyright (C) 2003, 2006 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
IN: kernel-internals
USING: vectors ;
: catchstack* ( -- catchstack )
6 getenv { vector } declare ; inline
IN: errors
USING: kernel kernel-internals ;
: catchstack ( -- catchstack ) catchstack* clone ; inline
: set-catchstack ( catchstack -- ) >vector 6 setenv ; inline
IN: kernel
USING: arrays namespaces sequences ;
TUPLE: continuation data retain call name catch ;
: continuation ( -- continuation )
datastack retainstack callstack namestack catchstack
<continuation> ; inline
: >continuation< ( continuation -- data retain call name catch )
[ continuation-data ] keep
[ continuation-retain ] keep
[ continuation-call ] keep
[ continuation-name ] keep
continuation-catch ; inline
: ifcc ( terminator balance -- )
>r >r f [ continuation nip t ] call r> r> if ; inline
: callcc0 ( quot -- ) [ ] ifcc ; inline
: callcc1 ( quot -- obj ) callcc0 ; inline
DEFER: continue-with
: set-walker-hook 2 setenv ; inline
: get-walker-hook 2 getenv f set-walker-hook ; inline
: (continue) ( continuation -- )
>continuation<
set-catchstack
set-namestack
set-callstack
set-retainstack
set-datastack ; inline
: (continue-with) ( obj continuation -- )
#! There's no good way to avoid this code duplication!
swap 9 setenv
>continuation<
set-catchstack
set-namestack
set-callstack
set-retainstack
set-datastack
9 getenv swap ; inline
: continue ( continuation -- )
get-walker-hook [ (continue-with) ] [ (continue) ] if* ;
inline
: continue-with ( obj continuation -- )
get-walker-hook [ >r 2array r> ] when* (continue-with) ;
inline
M: continuation clone
[ continuation-data clone ] keep
[ continuation-retain clone ] keep
[ continuation-call clone ] keep
[ continuation-name clone ] keep
continuation-catch clone <continuation> ;