[gforth] / gforth / look.fs  

gforth: gforth/look.fs


1 : anton 1.1 \ LOOK.FS xt -> lfa 22may93jaw
2 :    
3 : anton 1.14 \ Copyright (C) 1995,1996,1997,2000 Free Software Foundation, Inc.
4 : anton 1.3
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 : anton 1.15 \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
20 : anton 1.3
21 : anton 1.1 \ 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 : jwilke 1.8 \ look 17may93jaw
32 : anton 1.1
33 : jwilke 1.8 \ rename to discover!!!
34 : anton 1.1
35 :     : (look) ( xt startlfa -- lfa flag )
36 :     false swap
37 :     BEGIN @ dup
38 : anton 1.5 WHILE dup name>int
39 : anton 1.1 3 pick = IF nip dup THEN
40 :     REPEAT
41 :     drop nip
42 :     dup 0<> ;
43 :    
44 : jwilke 1.8
45 :     \ !!! nicht optimal!
46 :     [IFUNDEF] look
47 : jwilke 1.9 has? ec [IF]
48 :    
49 : jwilke 1.10 has? rom
50 : jwilke 1.8 [IF]
51 : jwilke 1.9 : look
52 :     dup [ unlock rom-dictionary area lock ]
53 :     literal literal within
54 :     IF
55 : anton 1.13 >head-noprim dup ?? <>
56 : jwilke 1.9 ELSE
57 :     forth-wordlist @ (look)
58 :     THEN ;
59 :     [ELSE]
60 : jwilke 1.8 : look ( cfa -- lfa flag )
61 : anton 1.13 >head-noprim dup ??? <> ;
62 : jwilke 1.9 [THEN]
63 : jwilke 1.8
64 :     [ELSE]
65 :    
66 : anton 1.13 : PrimStart ['] true >head-noprim ;
67 : jwilke 1.8
68 : anton 1.1 : look ( cfa -- lfa flag )
69 : anton 1.12 dup in-dictionary?
70 : jwilke 1.9 IF
71 : anton 1.13 >head-noprim dup ??? <>
72 : anton 1.12 ELSE
73 : jwilke 1.9 PrimStart (look)
74 :     THEN ;
75 : anton 1.1
76 : jwilke 1.8 [THEN]
77 :     [THEN]
78 : anton 1.13
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}

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