/** Rxhtable.c
  *
  *   DESCRIPTION:
  *   ===========
  *
  * This function finds the index associated with the function
  * name given in the argument string.
  *											
  * It uses a hashing function that was found using the program
  * 'hash' by W.G.J. Langeveld.
  *
  *   SYNOPSIS:
  *   =========
  *
  * index = rxhtable_index(name)
  *
  * int index the index of the function, -1 if not found.
  * char *name name of function.
  *
  *   AUTHOR/DATE:  W.G.J. Langeveld, November 1987.
  *   ============
  *
  *	CURRENT VERSION:
  *
  *	This version has been converted to SAS C 6.5 format. It has been modified
  *	for modern definition sequences for ANSI compilation. This no longer works
  *	with OS versions prior to 2.04.
  *
  *   AUTHOR/DATE:  Joanne Dow, jdow@bix.com, June 1998.
  *   ============
  *
  **/

#include <string.h>
#include <ctype.h>



static int hash_table[] = 
{
	-1,  -1,   8,  -1,  17,  -1,  18,   7,  -1,   9,
	 6,  15,  10,  -1,   0,  -1,  11,  -1,  -1,  21,
	 5,  12,  16,  14,  19,  13,  -1,  -1,  -1,   4,
	 1,   2,  -1,  -1,   3,  -1,  -1,  
};


int rxhtable_index(char *);
static int hash(unsigned char *);


int rxhtable_index( char *s )
{
	return(hash_table[hash(s)]);
}


static int hash( unsigned char *s )
{
	register int res;
	register unsigned char *sp;
	register unsigned int c;
	
	res = strlen(s);
	
	for (sp = s; *sp; sp++ ) 
	{
		c = toupper(*sp);
		res = ((res * 23 + c ) & 0x7ff);
	}
	return(res % 37);
}