[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 : jwilke 1.16 require stuff.fs
30 :     require environ.fs
31 :    
32 : anton 1.1 decimal
33 :    
34 : jwilke 1.8 \ look 17may93jaw
35 : anton 1.1
36 : jwilke 1.8 \ rename to discover!!!
37 : anton 1.1
38 :     : (look) ( xt startlfa -- lfa flag )
39 :     false swap
40 :     BEGIN @ dup
41 : anton 1.5 WHILE dup name>int
42 : anton 1.1 3 pick = IF nip dup THEN
43 :     REPEAT
44 :     drop nip
45 :     dup 0<> ;
46 :    
47 : jwilke 1.8
48 :     \ !!! nicht optimal!
49 :     [IFUNDEF] look
50 : jwilke 1.9 has? ec [IF]
51 :    
52 : jwilke 1.10 has? rom
53 : jwilke 1.8 [IF]
54 : jwilke 1.9 : look
55 :     dup [ unlock rom-dictionary area lock ]
56 :     literal literal within
57 :     IF
58 : anton 1.13 >head-noprim dup ?? <>
59 : jwilke 1.9 ELSE
60 :     forth-wordlist @ (look)
61 :     THEN ;
62 :     [ELSE]
63 : jwilke 1.8 : look ( cfa -- lfa flag )
64 : anton 1.13 >head-noprim dup ??? <> ;
65 : jwilke 1.9 [THEN]
66 : jwilke 1.8
67 :     [ELSE]
68 :    
69 : anton 1.13 : PrimStart ['] true >head-noprim ;
70 : jwilke 1.8
71 : anton 1.1 : look ( cfa -- lfa flag )
72 : anton 1.12 dup in-dictionary?
73 : jwilke 1.9 IF
74 : anton 1.13 >head-noprim dup ??? <>
75 : anton 1.12 ELSE
76 : jwilke 1.9 PrimStart (look)
77 :     THEN ;
78 : anton 1.1
79 : jwilke 1.8 [THEN]
80 :     [THEN]
81 : anton 1.13
82 :     : >head ( cfa -- nt|0 ) \ gforth to-head
83 :     \G tries to find the name token nt of the word represented by cfa;
84 :     \G returns 0 if it fails. This word is not absolutely reliable,
85 :     \G it may give false positives and produce wrong nts.
86 :     look and ;
87 :    
88 :     ' >head ALIAS >name \ gforth to-name
89 :     \G old name of @code{>head}

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