Annotation of gforth/look.fs, revision 1.16
1.1 anton 1: \ LOOK.FS xt -> lfa 22may93jaw
2:
1.14 anton 3: \ Copyright (C) 1995,1996,1997,2000 Free Software Foundation, Inc.
1.3 anton 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
1.15 anton 19: \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
1.3 anton 20:
1.1 anton 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:
1.16 ! jwilke 29: require stuff.fs
! 30: require environ.fs
! 31:
1.1 anton 32: decimal
33:
1.8 jwilke 34: \ look 17may93jaw
1.1 anton 35:
1.8 jwilke 36: \ rename to discover!!!
1.1 anton 37:
38: : (look) ( xt startlfa -- lfa flag )
39: false swap
40: BEGIN @ dup
1.5 anton 41: WHILE dup name>int
1.1 anton 42: 3 pick = IF nip dup THEN
43: REPEAT
44: drop nip
45: dup 0<> ;
46:
1.8 jwilke 47:
48: \ !!! nicht optimal!
49: [IFUNDEF] look
1.9 jwilke 50: has? ec [IF]
51:
1.10 jwilke 52: has? rom
1.8 jwilke 53: [IF]
1.9 jwilke 54: : look
55: dup [ unlock rom-dictionary area lock ]
56: literal literal within
57: IF
1.13 anton 58: >head-noprim dup ?? <>
1.9 jwilke 59: ELSE
60: forth-wordlist @ (look)
61: THEN ;
62: [ELSE]
1.8 jwilke 63: : look ( cfa -- lfa flag )
1.13 anton 64: >head-noprim dup ??? <> ;
1.9 jwilke 65: [THEN]
1.8 jwilke 66:
67: [ELSE]
68:
1.13 anton 69: : PrimStart ['] true >head-noprim ;
1.8 jwilke 70:
1.1 anton 71: : look ( cfa -- lfa flag )
1.12 anton 72: dup in-dictionary?
1.9 jwilke 73: IF
1.13 anton 74: >head-noprim dup ??? <>
1.12 anton 75: ELSE
1.9 jwilke 76: PrimStart (look)
77: THEN ;
1.1 anton 78:
1.8 jwilke 79: [THEN]
80: [THEN]
1.13 anton 81:
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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