File:  [gforth] / gforth / kernel / cloop2.fs
Revision 1.3: download - view: text, annotated - select for diffs
Sat Sep 23 15:47:09 2000 UTC (20 years, 10 months ago) by anton
Branches: MAIN
CVS tags: v0-5-0, HEAD
changed FSF address in copyright messages

    1: \ Structural Conditionals, loops no extra (?do)		10May99jaw
    2: 
    3: \ Copyright (C) 1995-1997,1999 Free Software Foundation, Inc.
    4: 
    5: \ This file is part of Gforth.
    6: 
    7: \ Gforth is free software; you can redistribute it and/or
    8: \ modify it under the terms of the GNU General Public License
    9: \ as published by the Free Software Foundation; either version 2
   10: \ of the License, or (at your option) any later version.
   11: 
   12: \ This program is distributed in the hope that it will be useful,
   13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
   14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   15: \ GNU General Public License for more details.
   16: 
   17: \ You should have received a copy of the GNU General Public License
   18: \ along with this program; if not, write to the Free Software
   19: \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
   20: 
   21: [IFDEF] (?do)
   22: 	cr ." Warning: (?do) is defined, use cloop.fs" 
   23: [THEN]
   24: 
   25: Variable tleavings 0 tleavings !
   26: 
   27: : DONE   ( addr -- )
   28:       tleavings @
   29:       BEGIN  dup
   30:       WHILE  >r dup r@ cell+ @ \ address of branch
   31:              u> 0=         \ lower than DO?
   32:       WHILE  r@ 2 cells + @ \ branch token
   33:              branchtoresolve,
   34:              r@ @ r> free throw
   35:       REPEAT drop r>
   36:       THEN
   37:       tleavings ! drop ; immediate restrict
   38: 
   39: : (leave ( branchtoken -- )
   40:     3 cells allocate throw >r
   41:     here r@ cell+ !
   42:     r@ 2 cells + !
   43:     tleavings @ r@ !
   44:     r> tleavings ! ;
   45: 
   46: : LEAVE     branchmark, (leave ;  		immediate restrict
   47: : ?LEAVE    compile 0= ?branchmark, (leave ;	immediate restrict
   48: 
   49: \ Structural Conditionals                              12dec92py
   50: 
   51: \ !!JW ToDo : Move to general tools section
   52: 
   53: : to1 ( x1 x2 xn n -- addr )
   54: \G packs n stack elements in a allocated memory region
   55:    dup dup 1+ cells allocate throw dup >r swap 1+ 0 DO tuck ! cell+ LOOP drop r> ;
   56: : 1to ( addr -- x1 x2 xn )
   57: \G unpacks the elements saved by to1
   58:    dup @ swap over cells + swap 0 DO dup @ swap 1 cells - LOOP free throw ;
   59: 
   60: : loop]     branchto, dup <resolve 1 cells - compile DONE ;
   61: 
   62: : skiploop] ?dup IF compile THEN THEN ;
   63: 
   64: : DO	0 compile (do) branchtomark, 2 to1  ;		immediate restrict
   65: 
   66: : ?DO 	compile 2dup compile = compile IF
   67: 	compile 2drop compile ELSE
   68: 	compile (do) branchtomark, 2 to1 ;		immediate restrict
   69: 
   70: : FOR   compile (for) branchtomark, ;			immediate restrict
   71: 
   72: : LOOP      sys?  1to compile (loop)  loop] compile unloop skiploop] ;     
   73: 							immediate restrict
   74: : +LOOP     sys? 1to compile (+loop)  loop] compile unloop skiploop] ;
   75: 							immediate restrict
   76: : NEXT      sys? compile (next)  loop] compile unloop ;
   77: 							immediate restrict
   78: : EXIT compile ;s ; immediate restrict
   79: : ?EXIT postpone IF postpone EXIT postpone THEN ; immediate restrict

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