/*******************************************************************************
*
* Project: seft (search engine for text)
*
* File: words.h
*
* Author: Owen de Kretser ([email protected])
*
* Organisation: Dept. of CS&SE, University of Melbourne
*
* Date: April 1999
*
* Purpose: word and non-word parsing macros
*
* Notes: adapted from the code by Neil Sharman and Tim Shimmin
*
*******************************************************************************/
/***** #includes **************************************************************/
#include <sys/types.h>
#include <ctype.h>
/***** #defines and Macros ****************************************************/
#define MAXWORDLEN 15
/* Maximum length in bytes of any word or non-word. Note that
variations to MAXWORDLEN may have dramatic effects on the rest
of the program, as the length and the prefix match are packed
together into a four bit nibble, and there is not check that
this is possible, i.e., leave MAXWORDLEN alone... */
#define MAXSTEMLEN 255
/* Maximum length in bytes of any stem. Note that
variations to MAXSTEMLEN may have dramatic effects on the rest
of the program, , i.e., leave MAXSTEMLEN alone... */
#define MAXNUMERIC 4
/* Maximum number of numeric characters permitted in a word.
This avoids mg_long sequences of numbers creating just one
word occurrence for each number. At most 10,000 all numeric
words will be permitted. */
#define INAWORD(c) (isascii(c) && isalnum(c))
/* The definition of what characters are permitted in a word
*/
#define INNUMBER(c) (isdigit(c)?1:0)
/*******************************************************************************
*
* Macro: PARSE_WORD
*
* Purpose: extract `pascal' word from text buffer
*
*******************************************************************************/
#define PARSE_WORD(Word, s_in, end) \
do \
{ \
register u_char *wptr = (Word)+1; \
register int length = 0; \
register int c = *(s_in); \
\
Word[2] = '\0'; \
while ( INAWORD(c) && length < MAXSTEMLEN && (s_in)<=(end)) \
{ \
*wptr++ = (c); \
length++; \
c = *++(s_in); \
} \
*(Word) = length; \
}while(0)
/*******************************************************************************
*
* Macro: PARSE_WORD_TOLOWER
*
* Purpose: extract `pascal' word from text buffer (characters tolower'd)
*
*******************************************************************************/
#define PARSE_WORD_TOLOWER(Word, s_in, end) \
do \
{ \
register u_char *wptr = (Word)+1; \
register int length = 0; \
register int c = *(s_in); \
register int numeric = 0; \
\
while ( length < MAXSTEMLEN && INAWORD(c) && (s_in)<=(end)) \
{ \
if ((numeric += INNUMBER(c)) > MAXNUMERIC) \
break; \
*wptr++ = tolower(c); \
length++; \
c = *++(s_in); \
} \
*(Word) = length; \
}while(0)
/*******************************************************************************
*
* Macro: PARSE_NON_WORD
*
* Purpose: extract `pascal' non-word from text buffer
*
*******************************************************************************/
#define PARSE_NON_WORD(Word,s_in, end) \
do \
{ \
register u_char *wptr = (Word)+1; \
register int length = 0; \
register int c = *(s_in); \
while (!INAWORD(c) && (s_in)<=(end)) \
{ \
*wptr++ = c; \
length++; \
c = *++(s_in); \
} \
*(Word) = length; \
}while(0)
/*******************************************************************************
*
* Macro: PARSE_NON_WORD
*
* Purpose: parse `pascal' non-word from text buffer, discard word
*
*******************************************************************************/
#define PARSE_NON_WORD_DISCARD(s_in, end) \
do \
{ \
while (!INAWORD(*(s_in)) && (s_in)<=(end)) \
(s_in)++; \
}while(0)
/*******************************************************************************
*
* Macro: PARSE_NON_WORD_FLAG
*
* Purpose: parse non-word from text buffer, discard word, check for ^B
*
*******************************************************************************/
#define PARSE_NON_WORD_FLAG(flag,s_in, end) \
do \
{ \
flag = 0; \
while (!INAWORD(*(s_in)) && (s_in)<=(end)) \
{ \
if (*(s_in) == '\002') \
flag = 1; \
(s_in)++; \
} \
}while(0)
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