🚀 go-pugleaf

Following is free code which anybody may use, it demonstrates how to build
symbols with out having to place and restrictions on their length.
I hope that everbody who
writes a compiler, linker, assembler, etc will look at this. Beleive me, there
don't need to be arbitrary limits, and I preffer products that do not have
arbitrary limits.

david.
DISCLAIMER: If it's important have a backup.  If it ain't broke don't fix it.
Proceed at your own risk.  My oponions are MY own.  Spelling does not count.
My fondest dream is to leave this planet.

----cut here---
/*****************************************************************************
* getsym.c
*
* This module implements a get sym(bol) function which reads the next
* symbol in from the input file descriptor, and returns a pointer to it.
*
* if TEST is defined at compile time, the following two routines are provided
* in order to test, and demonstrate getsym()
*
* put_sym_in_table() add symbols to a static symbol table.
*
* main() is a simple program to read words from the standard input, build
* a symbol table, print out the symbol table, free the symbols created, 
* and then free the symbol table.
*
* DISCLAIMER: This code worked the first time I tried it, so obviously there
* is something wrong with it.  Assume it is defective until proven otherwise.
*
* if BULLET_PROOF is defined at compile time, additional bullet proofing is
* added, that is not required for normal operation.
*
* BASIC_SYMBOL_SIZE can be defined on the command line to override the basic
* symbol size assumed by this module.
*
* HINT: tab 4,9
*
* First Created: 25 July 1989 by david 
* Last Modified: 25 July 1989 by david 
*****************************************************************************/

#include <stdio.h>

extern char *malloc(),*realloc();
				 					 
/*
* these values, BASIC_SYMBOL_SIZE and BASIC_TABLE_SIZE are given small
* values for debugging purposes.
*/
#ifndef BASIC_SYMBOL_SIZE
#define BASIC_SYMBOL_SIZE	4	/* this value defines the first guess*/
										/* as to the size of the symbol.  If that */
										/* guess is wrong, it is guessed that that */
										/* much more space will be required. The */
										/* actual value effects the speed of */
										/* the routine, that's all */
#endif
										
#ifndef BASIC_TABLE_SIZE
#define BASIC_TABLE_SIZE	4	/* this value defines the first guess */
										/* as to the number of table entries. */
										/* if this guess is wrong, it is guessed */
										/* that that many more entries will be */
										/* required */
#endif
/*****************************************************************************
* char *getsym(f)
*
* INPUT:
* f is the file descriptor to read the next symbol from.
*
* OUTPUT:
* a pointer to the next symbol on the input is returned.  This buffer has
* been malloc()ed and should be free()ed when it is nolonger needed. if
* NULL is returned there was an error getting the next string, if (-1) is
* returned there were no more symbols.
*
* First Created: 25 July 1989 by david 
* Last Modified: 25 July 1989 by david 
*****************************************************************************/
char *getsym(f)
FILE *f;
{	char *tmp;
	int actual_symbol_size;
	int symbol_size;
	char c;
	actual_symbol_size=BASIC_SYMBOL_SIZE;	
	symbol_size=0;
	/* get the initial buffer for the symbol */
	if((tmp=(char *)malloc(actual_symbol_size))==NULL)
	{
#ifdef BULLET_PROOF	
		fprintf(stderr,"getsym: malloc() returned NULL\n");
		exit(0);
#endif
		return NULL;
	}
	while((c=getc(f))!=EOF)
	{	if( (c>='A' && c <='Z') || (c>='a' && c <='z') )
		{	if(symbol_size>=actual_symbol_size)
			/* if we need more buffer area */
			{	actual_symbol_size+=BASIC_SYMBOL_SIZE;
				if((tmp=(char *)realloc(tmp,actual_symbol_size))==NULL)
				{
#ifdef BULLET_PROOF	
					fprintf(stderr,"getsym: realloc() returned NULL\n");
					exit(0);
#endif
					return NULL;
				}
			}
			tmp[symbol_size++]=c;
		}else
		{	if(symbol_size)
			/* if there is atleast one character in the symbol */
			{ 	if((tmp=(char *)realloc(tmp,symbol_size+1))==NULL)
				{	
#ifdef BULLET_PROOF	
					fprintf(stderr,"getsym: realloc() returned NULL\n");
					exit(0);
#endif
					return NULL;
				}
				tmp[symbol_size]='\0'; /* terminate the symbol */
				return(tmp); /* return the pointer to the symbol */
			}else
			/* eat up separators until there is atleas one non separator */
			{	continue;
			}
		}
	}
	/* we got an EOF */
	if(symbol_size)
	/* if we read in a symobol, return it */
	{	return(tmp);
	}else
	/* if we did not find a symbol, return (-1) */
	{	return((char *)(-1));
	}
}
#ifdef TEST
/*****************************************************************************
* put_sym_in_table(sym)
*
* put the symbol in the symbol table.  If there is a problem, print a useful
* message and exit();
*
* First Created: 25 July 1989 by david 
* Last Modified: 25 July 1989 by david 
*****************************************************************************/
static char **symbol_table;
static unsigned int table_size=0;
static unsigned int actual_table_size=0;

put_sym_in_table(sym)
char *sym;
{	if(actual_table_size==0)
	{	if((symbol_table=(char **)
			malloc(actual_table_size*sizeof(char *)))==NULL)
		{	fprintf(stderr,"put_sym_in_table: malloc() returned NULL\n");
			exit(0);	
		}
	}
	if(table_size >= actual_table_size)
	{	actual_table_size+=BASIC_TABLE_SIZE;
		if((symbol_table=	(char **)
					realloc(symbol_table,actual_table_size*sizeof(char *)))==NULL)
		{	fprintf(stderr,"put_sym_in_table: realloc() returned NULL\n");
			exit(0);	
		}
	}
	symbol_table[table_size++]=sym;
}
/*****************************************************************************
* main()
*
* This is a simple demonstration program for getsym and put_sym_in_table.
*
* First Created: 25 July 1989 by david 
* Last Modified: 25 July 1989 by david 
*****************************************************************************/
main()
{	char *tmp;
	unsigned int i;
	while((tmp=getsym(stdin))!=((char *)(-1)))
	{	if(tmp==NULL)
		{	fprintf(stderr,"main: getsym returned NULL\n");
			exit(0);
		}
		put_sym_in_table(tmp);
	}
	for(i=0;i<table_size;i++)
	{	fprintf(stdout,"symbol_table[%d]=%s\n",i,symbol_table[i]);
		free(symbol_table[i]);
	}
	free(symbol_table);
}
#endif


-- 
david.
DISCLAIMER: If it's important have a backup.  If it ain't broke don't fix it.
Proceed at your own risk.  My oponions are MY own.  Spelling does not count.
My fondest dream is to leave this planet.