Annotation of gforth/kernel/cloop2.fs, revision 1.7

1.1       jwilke      1: \ Structural Conditionals, loops no extra (?do)                10May99jaw
                      2: 
1.7     ! anton       3: \ Copyright (C) 1995-1997,1999,2000,2003,2007 Free Software Foundation, Inc.
1.1       jwilke      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
1.6       anton       9: \ as published by the Free Software Foundation, either version 3
1.1       jwilke     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
1.6       anton      18: \ along with this program. If not, see http://www.gnu.org/licenses/.
1.1       jwilke     19: 
                     20: [IFDEF] (?do)
                     21:        cr ." Warning: (?do) is defined, use cloop.fs" 
                     22: [THEN]
                     23: 
                     24: Variable tleavings 0 tleavings !
                     25: 
                     26: : DONE   ( addr -- )
                     27:       tleavings @
                     28:       BEGIN  dup
                     29:       WHILE  >r dup r@ cell+ @ \ address of branch
                     30:              u> 0=         \ lower than DO?
                     31:       WHILE  r@ 2 cells + @ \ branch token
                     32:              branchtoresolve,
                     33:              r@ @ r> free throw
                     34:       REPEAT drop r>
                     35:       THEN
                     36:       tleavings ! drop ; immediate restrict
                     37: 
                     38: : (leave ( branchtoken -- )
                     39:     3 cells allocate throw >r
                     40:     here r@ cell+ !
                     41:     r@ 2 cells + !
                     42:     tleavings @ r@ !
                     43:     r> tleavings ! ;
                     44: 
                     45: : LEAVE     branchmark, (leave ;               immediate restrict
                     46: : ?LEAVE    compile 0= ?branchmark, (leave ;   immediate restrict
                     47: 
                     48: \ Structural Conditionals                              12dec92py
                     49: 
                     50: \ !!JW ToDo : Move to general tools section
                     51: 
                     52: : to1 ( x1 x2 xn n -- addr )
                     53: \G packs n stack elements in a allocated memory region
                     54:    dup dup 1+ cells allocate throw dup >r swap 1+ 0 DO tuck ! cell+ LOOP drop r> ;
                     55: : 1to ( addr -- x1 x2 xn )
                     56: \G unpacks the elements saved by to1
                     57:    dup @ swap over cells + swap 0 DO dup @ swap 1 cells - LOOP free throw ;
                     58: 
                     59: : loop]     branchto, dup <resolve 1 cells - compile DONE ;
                     60: 
                     61: : skiploop] ?dup IF compile THEN THEN ;
                     62: 
                     63: : DO   0 compile (do) branchtomark, 2 to1  ;           immediate restrict
                     64: 
                     65: : ?DO  compile 2dup compile = compile IF
                     66:        compile 2drop compile ELSE
                     67:        compile (do) branchtomark, 2 to1 ;              immediate restrict
                     68: 
                     69: : FOR   compile (for) branchtomark, ;                  immediate restrict
                     70: 
                     71: : LOOP      sys?  1to compile (loop)  loop] compile unloop skiploop] ;     
                     72:                                                        immediate restrict
                     73: : +LOOP     sys? 1to compile (+loop)  loop] compile unloop skiploop] ;
                     74:                                                        immediate restrict
                     75: : NEXT      sys? compile (next)  loop] compile unloop ;
                     76:                                                        immediate restrict
                     77: : EXIT compile ;s ; immediate restrict
                     78: : ?EXIT postpone IF postpone EXIT postpone THEN ; immediate restrict

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