File:  [gforth] / gforth / look.fs
Revision 1.4: download - view: text, annotated - select for diffs
Mon May 13 16:37:01 1996 UTC (23 years, 9 months ago) by anton
Branches: MAIN
CVS tags: HEAD
eliminated state-smartness in ;code and sfnumber
immediate-flag is now $40 and restrict-flag $20
HEADER now stores the compilation wordlist in the header and
	REVEAL reveals into that wordlist
assorted cleanups

    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: \ >NAME PRIMSTART                                       22may93jaw
   32: 
   33: \ : >name ( xt -- nfa )
   34: \         BEGIN   1 chars -
   35: \                 dup c@ alias-mask and
   36: \         UNTIL ;
   37: 
   38: : PrimStart ['] true >name ;
   39: 
   40: \ look                                                  17may93jaw
   41: 
   42: : (look)  ( xt startlfa -- lfa flag )
   43:         false swap
   44:         BEGIN @ dup
   45:         WHILE dup name>
   46:               3 pick = IF nip dup THEN
   47:         REPEAT
   48:         drop nip
   49:         dup 0<> ;
   50: 
   51: : look ( cfa -- lfa flag )
   52:         dup forthstart <
   53:         IF PrimStart (look)
   54:         ELSE >name true THEN ;
   55: 

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