Annotation of gforth/kernel-ec/cbr.fs, revision 1.2

1.1       pazsan      1: \ Structural Conditionals, based on branches               12dec92py
                      2: 
1.2     ! anton       3: \ Copyright (C) 1995,1996,1997,1999,2001,2003,2006,2007,2012 Free Software Foundation, Inc.
1.1       pazsan      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 3
                     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, see http://www.gnu.org/licenses/.
                     19: 
                     20: : ?struc      ( flag -- )       abort" unstructured " ;
                     21: : sys?        ( sys -- )        dup 0= ?struc ;
                     22: : >mark       ( -- sys )        here  cell allot ;
                     23: : >resolve    ( sys -- )        here swap
                     24:     [ has? flash [IF] ] flash! [ [ELSE] ] ! [  [THEN] ] ;
                     25: : <resolve    ( sys -- )        , ;
                     26: 
                     27: : BUT       sys? swap ;                      immediate restrict
                     28: : YET       sys? dup ;                       immediate restrict
                     29: 
                     30: \ Structural Conditionals                              12dec92py
                     31: 
                     32: : AHEAD     postpone branch >mark ;           immediate restrict
                     33: : IF        postpone ?branch >mark ;          immediate restrict
                     34: : THEN      sys? ( dup @ ?struc ) >resolve ;  immediate restrict
                     35: : ELSE      sys? postpone AHEAD swap postpone THEN ;
                     36:                                              immediate restrict
                     37: 
                     38: ' THEN Alias ENDIF immediate restrict
                     39: 
                     40: : BEGIN     here ;                           immediate restrict
                     41: : WHILE     sys? postpone IF swap ;           immediate restrict
                     42: : AGAIN     sys? postpone branch  <resolve ;  immediate restrict
                     43: : UNTIL     sys? postpone ?branch <resolve ;  immediate restrict
                     44: : REPEAT    over 0= ?struc postpone AGAIN postpone THEN ;
                     45:                                              immediate restrict
                     46: 
                     47: 0 CONSTANT case ( compilation  -- case-sys ; run-time  -- ) \ core-ext
                     48:     immediate
                     49: 
                     50: : of ( compilation  -- of-sys ; run-time x1 x2 -- |x1 ) \ core-ext
                     51:     \ !! the implementation does not match the stack effect
                     52:     1+ >r
                     53:     postpone over postpone = postpone if postpone drop
                     54:     r> ; immediate
                     55: 
                     56: : endof ( compilation case-sys1 of-sys -- case-sys2 ; run-time  -- ) \ core-ext end-of
                     57:     >r postpone else r> ; immediate
                     58: 
                     59: : endcase ( compilation case-sys -- ; run-time x -- ) \ core-ext end-case
                     60:     postpone drop
                     61:     0 ?do postpone then loop ; immediate

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>