1/*******************************************************************
2** p r e f i x . c
3** Forth Inspired Command Language
4** Parser extensions for Ficl
5** Authors: Larry Hastings & John Sadler (john_sadler@alum.mit.edu)
6** Created: April 2001
7** $Id: prefix.c,v 1.6 2001/12/05 07:21:34 jsadler Exp $
8*******************************************************************/
9/*
10** Copyright (c) 1997-2001 John Sadler (john_sadler@alum.mit.edu)
11** All rights reserved.
12**
13** Get the latest Ficl release at http://ficl.sourceforge.net
14**
15** I am interested in hearing from anyone who uses ficl. If you have
16** a problem, a success story, a defect, an enhancement request, or
17** if you would like to contribute to the ficl release, please
18** contact me by email at the address above.
19**
20** L I C E N S E  and  D I S C L A I M E R
21**
22** Redistribution and use in source and binary forms, with or without
23** modification, are permitted provided that the following conditions
24** are met:
25** 1. Redistributions of source code must retain the above copyright
26**    notice, this list of conditions and the following disclaimer.
27** 2. Redistributions in binary form must reproduce the above copyright
28**    notice, this list of conditions and the following disclaimer in the
29**    documentation and/or other materials provided with the distribution.
30**
31** THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
32** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
33** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34** ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
35** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
39** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
40** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
41** SUCH DAMAGE.
42*/
43
44
45#include <string.h>
46#include <ctype.h>
47#include "ficl.h"
48#include "math64.h"
49
50/*
51** (jws) revisions:
52** A prefix is a word in a dedicated wordlist (name stored in list_name below)
53** that is searched in a special way by the prefix parse step. When a prefix
54** matches the beginning of an incoming token, push the non-prefix part of the
55** token back onto the input stream and execute the prefix code.
56**
57** The parse step is called ficlParsePrefix.
58** Storing prefix entries in the dictionary greatly simplifies
59** the process of matching and dispatching prefixes, avoids the
60** need to clean up a dynamically allocated prefix list when the system
61** goes away, but still allows prefixes to be allocated at runtime.
62*/
63
64static char list_name[] = "<prefixes>";
65
66/**************************************************************************
67                        f i c l P a r s e P r e f i x
68** This is the parse step for prefixes - it checks an incoming word
69** to see if it starts with a prefix, and if so runs the corrseponding
70** code against the remainder of the word and returns true.
71**************************************************************************/
72int ficlParsePrefix(FICL_VM *pVM, STRINGINFO si)
73{
74    int i;
75    FICL_HASH *pHash;
76    FICL_WORD *pFW = ficlLookup(pVM->pSys, list_name);
77
78    /*
79    ** Make sure we found the prefix dictionary - otherwise silently fail
80    ** If forth-wordlist is not in the search order, we won't find the prefixes.
81    */
82    if (!pFW)
83        return FICL_FALSE;
84
85    pHash = (FICL_HASH *)(pFW->param[0].p);
86    /*
87    ** Walk the list looking for a match with the beginning of the incoming token
88    */
89    for (i = 0; i < (int)pHash->size; i++)
90    {
91        pFW = pHash->table[i];
92        while (pFW != NULL)
93        {
94            int n;
95            n = pFW->nName;
96            /*
97            ** If we find a match, adjust the TIB to give back the non-prefix characters
98            ** and execute the prefix word.
99            */
100            if (!strincmp(SI_PTR(si), pFW->name, (FICL_UNS)n))
101            {
102                /* (sadler) fixed off-by-one error when the token has no trailing space in the TIB */
103				vmSetTibIndex(pVM, si.cp + n - pVM->tib.cp );
104                vmExecute(pVM, pFW);
105
106                return (int)FICL_TRUE;
107            }
108            pFW = pFW->link;
109        }
110    }
111
112    return FICL_FALSE;
113}
114
115
116static void tempBase(FICL_VM *pVM, int base)
117{
118    int oldbase = pVM->base;
119    STRINGINFO si = vmGetWord0(pVM);
120
121    pVM->base = base;
122    if (!ficlParseNumber(pVM, si))
123    {
124        int i = SI_COUNT(si);
125        vmThrowErr(pVM, "%.*s not recognized", i, SI_PTR(si));
126    }
127
128    pVM->base = oldbase;
129    return;
130}
131
132static void fTempBase(FICL_VM *pVM)
133{
134    int base = stackPopINT(pVM->pStack);
135    tempBase(pVM, base);
136    return;
137}
138
139static void prefixHex(FICL_VM *pVM)
140{
141    tempBase(pVM, 16);
142}
143
144static void prefixTen(FICL_VM *pVM)
145{
146    tempBase(pVM, 10);
147}
148
149
150/**************************************************************************
151                        f i c l C o m p i l e P r e f i x
152** Build prefix support into the dictionary and the parser
153** Note: since prefixes always execute, they are effectively IMMEDIATE.
154** If they need to generate code in compile state you must add
155** this code explicitly.
156**************************************************************************/
157void ficlCompilePrefix(FICL_SYSTEM *pSys)
158{
159    FICL_DICT *dp = pSys->dp;
160    FICL_HASH *pHash;
161    FICL_HASH *pPrevCompile = dp->pCompile;
162#if (FICL_EXTENDED_PREFIX)
163    FICL_WORD *pFW;
164#endif
165
166    /*
167    ** Create a named wordlist for prefixes to reside in...
168    ** Since we're doing a special kind of search, make it
169    ** a single bucket hashtable - hashing does not help here.
170    */
171    pHash = dictCreateWordlist(dp, 1);
172    pHash->name = list_name;
173    dictAppendWord(dp, list_name, constantParen, FW_DEFAULT);
174    dictAppendCell(dp, LVALUEtoCELL(pHash));
175
176	/*
177	** Put __tempbase in the forth-wordlist
178	*/
179    dictAppendWord(dp, "__tempbase", fTempBase, FW_DEFAULT);
180
181    /*
182    ** Temporarily make the prefix list the compile wordlist so that
183    ** we can create some precompiled prefixes.
184    */
185    dp->pCompile = pHash;
186    dictAppendWord(dp, "0x", prefixHex, FW_DEFAULT);
187    dictAppendWord(dp, "0d", prefixTen, FW_DEFAULT);
188#if (FICL_EXTENDED_PREFIX)
189    pFW = ficlLookup(pSys, "\\");
190    if (pFW)
191    {
192        dictAppendWord(dp, "//", pFW->code, FW_DEFAULT);
193    }
194#endif
195    dp->pCompile = pPrevCompile;
196
197    return;
198}
199