stand/ficl/prefix.c

   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
  64 static 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 **************************************************************************/
  72 int 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
 116 static 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
 132 static void fTempBase(FICL_VM *pVM)
 133 {
 134     int base = stackPopINT(pVM->pStack);
 135     tempBase(pVM, base);
 136     return;
 137 }
 138
 139 static void prefixHex(FICL_VM *pVM)
 140 {
 141     tempBase(pVM, 16);
 142 }
 143
 144 static 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 **************************************************************************/
 157 void 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 }