summaryrefslogtreecommitdiffstats
path: root/sys/boot/ficl/prefix.c
blob: a34fc6c78240e4b9106fd43a8f551536b5db19a5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
/*******************************************************************
** p r e f i x . c
** Forth Inspired Command Language
** Parser extensions for Ficl
** Authors: Larry Hastings & John Sadler (john_sadler@alum.mit.edu)
** Created: April 2001
** $Id: prefix.c,v 1.6 2001/12/05 07:21:34 jsadler Exp $
*******************************************************************/
/*
** Copyright (c) 1997-2001 John Sadler (john_sadler@alum.mit.edu)
** All rights reserved.
**
** Get the latest Ficl release at http://ficl.sourceforge.net
**
** I am interested in hearing from anyone who uses ficl. If you have
** a problem, a success story, a defect, an enhancement request, or
** if you would like to contribute to the ficl release, please
** contact me by email at the address above.
**
** L I C E N S E  and  D I S C L A I M E R
** 
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
** 1. Redistributions of source code must retain the above copyright
**    notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
**    notice, this list of conditions and the following disclaimer in the
**    documentation and/or other materials provided with the distribution.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
** ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
** SUCH DAMAGE.
*/

/* $FreeBSD$ */

#include <string.h>
#include <ctype.h>
#include "ficl.h"
#include "math64.h"

/*
** (jws) revisions: 
** A prefix is a word in a dedicated wordlist (name stored in list_name below)
** that is searched in a special way by the prefix parse step. When a prefix
** matches the beginning of an incoming token, push the non-prefix part of the
** token back onto the input stream and execute the prefix code.
**
** The parse step is called ficlParsePrefix. 
** Storing prefix entries in the dictionary greatly simplifies
** the process of matching and dispatching prefixes, avoids the
** need to clean up a dynamically allocated prefix list when the system
** goes away, but still allows prefixes to be allocated at runtime.
*/

static char list_name[] = "<prefixes>";

/**************************************************************************
                        f i c l P a r s e P r e f i x
** This is the parse step for prefixes - it checks an incoming word
** to see if it starts with a prefix, and if so runs the corrseponding
** code against the remainder of the word and returns true.
**************************************************************************/
int ficlParsePrefix(FICL_VM *pVM, STRINGINFO si)
{
    int i;
    FICL_HASH *pHash;
    FICL_WORD *pFW = ficlLookup(pVM->pSys, list_name);

    /* 
    ** Make sure we found the prefix dictionary - otherwise silently fail
    ** If forth-wordlist is not in the search order, we won't find the prefixes.
    */
    if (!pFW)
        return FICL_FALSE;

    pHash = (FICL_HASH *)(pFW->param[0].p);
    /*
    ** Walk the list looking for a match with the beginning of the incoming token
    */
    for (i = 0; i < (int)pHash->size; i++)
    {
        pFW = pHash->table[i];
        while (pFW != NULL)
        {
            int n;
            n = pFW->nName;
            /*
            ** If we find a match, adjust the TIB to give back the non-prefix characters
            ** and execute the prefix word.
            */
            if (!strincmp(SI_PTR(si), pFW->name, (FICL_UNS)n))
            {
                /* (sadler) fixed off-by-one error when the token has no trailing space in the TIB */
				vmSetTibIndex(pVM, si.cp + n - pVM->tib.cp );
                vmExecute(pVM, pFW);

                return (int)FICL_TRUE;
            }
            pFW = pFW->link;
        }
    }

    return FICL_FALSE;
}


static void tempBase(FICL_VM *pVM, int base)
{
    int oldbase = pVM->base;
    STRINGINFO si = vmGetWord0(pVM);

    pVM->base = base;
    if (!ficlParseNumber(pVM, si)) 
    {
        int i = SI_COUNT(si);
        vmThrowErr(pVM, "%.*s not recognized", i, SI_PTR(si));
    }

    pVM->base = oldbase;
    return;
}

static void fTempBase(FICL_VM *pVM)
{
    int base = stackPopINT(pVM->pStack);
    tempBase(pVM, base);
    return;
}

static void prefixHex(FICL_VM *pVM)
{
    tempBase(pVM, 16);
}

static void prefixTen(FICL_VM *pVM)
{
    tempBase(pVM, 10);
}


/**************************************************************************
                        f i c l C o m p i l e P r e f i x
** Build prefix support into the dictionary and the parser
** Note: since prefixes always execute, they are effectively IMMEDIATE.
** If they need to generate code in compile state you must add
** this code explicitly.
**************************************************************************/
void ficlCompilePrefix(FICL_SYSTEM *pSys)
{
    FICL_DICT *dp = pSys->dp;
    FICL_HASH *pHash;
    FICL_HASH *pPrevCompile = dp->pCompile;
#if (FICL_EXTENDED_PREFIX)
    FICL_WORD *pFW;
#endif
    
    /*
    ** Create a named wordlist for prefixes to reside in...
    ** Since we're doing a special kind of search, make it
    ** a single bucket hashtable - hashing does not help here.
    */
    pHash = dictCreateWordlist(dp, 1);
    pHash->name = list_name;
    dictAppendWord(dp, list_name, constantParen, FW_DEFAULT);
    dictAppendCell(dp, LVALUEtoCELL(pHash));

	/*
	** Put __tempbase in the forth-wordlist
	*/
    dictAppendWord(dp, "__tempbase", fTempBase, FW_DEFAULT);

    /*
    ** Temporarily make the prefix list the compile wordlist so that
    ** we can create some precompiled prefixes.
    */
    dp->pCompile = pHash;
    dictAppendWord(dp, "0x", prefixHex, FW_DEFAULT);
    dictAppendWord(dp, "0d", prefixTen, FW_DEFAULT);
#if (FICL_EXTENDED_PREFIX)
    pFW = ficlLookup(pSys, "\\");
    if (pFW)
    {
        dictAppendWord(dp, "//", pFW->code, FW_DEFAULT);
    }
#endif
    dp->pCompile = pPrevCompile;

    return;
}
OpenPOWER on IntegriCloud