ref: 7d02e382d314d5bdde7978ccb7a64ea9201d03db
dir: /prefix.c/
/*******************************************************************
** 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 1.9 2010/11/01 14:10:27 asau 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.
*/
#include <string.h>
#include <ctype.h>
#include "ficl.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 corresponding
** code against the remainder of the word and returns true.
**************************************************************************/
int ficlVmParsePrefix(ficlVm *vm, ficlString s)
{
int i;
ficlHash *hash;
ficlWord *word = ficlSystemLookup(vm->callback.system, 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 (!word)
return 0; /* false */
hash = (ficlHash *)(word->param[0].p);
/*
** Walk the list looking for a match with the beginning of the incoming token
*/
for (i = 0; i < (int)hash->size; i++)
{
word = hash->table[i];
while (word != NULL)
{
int n;
n = word->length;
/*
** If we find a match, adjust the TIB to give back the non-prefix characters
** and execute the prefix word.
*/
if (!ficlStrincmp(FICL_STRING_GET_POINTER(s), word->name, (ficlUnsigned)n))
{
/* (sadler) fixed off-by-one error when the token has no trailing space in the TIB */
ficlVmSetTibIndex(vm, s.text + n - vm->tib.text);
ficlVmExecuteWord(vm, word);
return 1; /* true */
}
word = word->link;
}
}
return 0; /* false */
}
static void ficlPrimitiveTempBase(ficlVm *vm)
{
int oldbase = vm->base;
ficlString number = ficlVmGetWord0(vm);
int base = ficlStackPopInteger(vm->dataStack);
vm->base = base;
if (!ficlVmParseNumber(vm, number))
ficlVmThrowError(vm, "%.*s not recognized", FICL_STRING_GET_LENGTH(number), FICL_STRING_GET_POINTER(number));
vm->base = oldbase;
return;
}
/**************************************************************************
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 ficlSystemCompilePrefix(ficlSystem *system)
{
ficlDictionary *dictionary = system->dictionary;
ficlHash *hash;
/*
** 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.
*/
hash = ficlDictionaryCreateWordlist(dictionary, 1);
hash->name = list_name;
ficlDictionaryAppendConstantPointer(dictionary, list_name, hash);
/*
** Put __tempbase in the forth-wordlist
*/
ficlDictionarySetPrimitive(dictionary, "__tempbase", ficlPrimitiveTempBase, FICL_WORD_DEFAULT);
/*
** If you want to add some prefixes at compilation-time, copy this line to the top of this function:
**
ficlHash *oldCompilationWordlist;
**
** then copy this code to the bottom, just above the return:
**
oldCompilationWordlist = dictionary->compilationWordlist;
dictionary->compilationWordlist = hash;
ficlDictionarySetPrimitive(dictionary, YOUR WORD HERE, FICL_WORD_DEFAULT);
dictionary->compilationWordlist = oldCompilationWordlist;
**
** and substitute in your own actual calls to ficlDictionarySetPrimitive() as needed.
**
** Or--better yet--do it in your own code, so you don't have to re-modify the Ficl
** source code every time we cut a new release!
*/
return;
}