File:
[gforth] /
gforth /
look.fs
Revision
1.13:
download - view:
text,
annotated -
select for diffs
Sat May 27 09:41:28 2000 UTC (23 years, 10 months ago) by
anton
Branches:
MAIN
CVS tags:
HEAD
renamed old >HEAD/>NAME into >HEAD-NOPRIM, defined >HEAD/>NAME to also
work on primitives.
>HEAD/>NAME now returns 0 (instead of the nt of ???) on failure.
1: \ LOOK.FS xt -> lfa 22may93jaw
2:
3: \ Copyright (C) 1995,1996,1997 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: \ look 17may93jaw
32:
33: \ rename to discover!!!
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:
45: \ !!! nicht optimal!
46: [IFUNDEF] look
47: has? ec [IF]
48:
49: has? rom
50: [IF]
51: : look
52: dup [ unlock rom-dictionary area lock ]
53: literal literal within
54: IF
55: >head-noprim dup ?? <>
56: ELSE
57: forth-wordlist @ (look)
58: THEN ;
59: [ELSE]
60: : look ( cfa -- lfa flag )
61: >head-noprim dup ??? <> ;
62: [THEN]
63:
64: [ELSE]
65:
66: : PrimStart ['] true >head-noprim ;
67:
68: : look ( cfa -- lfa flag )
69: dup in-dictionary?
70: IF
71: >head-noprim dup ??? <>
72: ELSE
73: PrimStart (look)
74: THEN ;
75:
76: [THEN]
77: [THEN]
78:
79: : >head ( cfa -- nt|0 ) \ gforth to-head
80: \G tries to find the name token nt of the word represented by cfa;
81: \G returns 0 if it fails. This word is not absolutely reliable,
82: \G it may give false positives and produce wrong nts.
83: look and ;
84:
85: ' >head ALIAS >name \ gforth to-name
86: \G old name of @code{>head}
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>