File:  [gforth] / gforth / look.fs
Revision 1.7: download - view: text, annotated - select for diffs
Thu Mar 27 13:31:02 1997 UTC (23 years ago) by anton
Branches: MAIN
CVS tags: v0-3-0, HEAD
threw out blocks.fs:include (would confuse users)
added dictionary-end
script? is now set correctly
look and represent now work correctly on the Alpha

    1: \ LOOK.FS      xt -> lfa                               22may93jaw
    2: 
    3: \ Copyright (C) 1995 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., 675 Mass Ave, Cambridge, MA 02139, USA.
   20: 
   21: \ Look checks first if the word is a primitive. If yes then the
   22: \ vocabulary in the primitive area is beeing searched, meaning
   23: \ creating for each word a xt and comparing it...
   24: 
   25: \ If a word is no primitive look searches backwards to find the nfa.
   26: \ Problems: A compiled xt via compile, might be created with noname:
   27: \           a noname: leaves now a empty name field
   28: 
   29: decimal
   30: 
   31: : PrimStart ['] true >name ;
   32: 
   33: \ look                                                  17may93jaw
   34: 
   35: : (look)  ( xt startlfa -- lfa flag )
   36:         false swap
   37:         BEGIN @ dup
   38:         WHILE dup name>int
   39:               3 pick = IF nip dup THEN
   40:         REPEAT
   41:         drop nip
   42:         dup 0<> ;
   43: 
   44: : look ( cfa -- lfa flag )
   45:         dup dictionary-end forthstart within
   46: 	IF
   47: 	    PrimStart (look)
   48: 	ELSE
   49: 	    >name dup ??? <>
   50: 	THEN ;
   51: 

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