\ Structural Conditionals, loops part                  12dec92py

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\ Structural Conditionals                              12dec92py

Variable leavings

: (leave)   here  leavings @ ,  leavings ! ;
: LEAVE     postpone branch  (leave) ;  immediate restrict
: ?LEAVE    postpone 0= postpone ?branch  (leave) ;
                                             immediate restrict

: DONE   ( addr -- )  leavings @
  BEGIN  2dup u<=  WHILE  dup @ swap >resolve  REPEAT
  leavings ! drop ;                          immediate restrict

\ Structural Conditionals                              12dec92py

: DO        postpone (do)   here ;            immediate restrict

: ?DO       postpone (?do)  (leave) here ;
                                             immediate restrict
: FOR       postpone (for)  here ;            immediate restrict

: loop]     dup <resolve 2 cells - postpone done postpone unloop ;

: LOOP      sys? postpone (loop)  loop] ;     immediate restrict
: +LOOP     sys? postpone (+loop) loop] ;     immediate restrict
: NEXT      sys? postpone (next)  loop] ;     immediate restrict

: EXIT postpone ;s ; immediate restrict
: ?EXIT postpone IF postpone EXIT postpone THEN ; immediate restrict

