/* Copyright (C) 1989, 1990 Aladdin Enterprises.  All rights reserved.
   Distributed by Free Software Foundation, Inc.

This file is part of Ghostscript.

Ghostscript is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
to anyone for the consequences of using it or for whether it serves any
particular purpose or works at all, unless he says so in writing.  Refer
to the Ghostscript General Public License for full details.

Everyone is granted permission to copy, modify and redistribute
Ghostscript, but only under the conditions described in the Ghostscript
General Public License.  A copy of this license is supposed to have been
given to you along with Ghostscript so you can know your rights and
responsibilities.  It should be in a file named COPYING.  Among other
things, the copyright notice and this notice must be preserved on all
copies.  */

/* zstring.c */
/* String operators for GhostScript */
#include "memory_.h"
#include "ghost.h"
#include "alloc.h"
#include "errors.h"
#include "oper.h"
#include "store.h"
#include "stream.h"

/* The generic operators (copy, get, put, getinterval, putinterval, */
/* length, and forall) are implemented in zgeneric.c. */

/* string */
int
zstring(register ref *op)
{	byte *sbody;
	uint size;
	check_type(*op, t_integer);
	if ( op->value.intval < 0 || (ulong)(op->value.intval) > max_uint )
		return e_rangecheck;
	size = op->value.intval;
	sbody = (byte *)alloc(size, 1, "string");
	if ( sbody == 0 ) return e_VMerror;
	make_tasv(op, t_string, a_all, size, bytes, sbody);
	memset(sbody, 0, size);
	return 0;
}

/* anchorsearch */
int
zanchorsearch(register ref *op)
{	ref *op1 = op - 1;
	uint size = op->size;
	check_read_type(*op1, t_string);
	check_read_type(*op, t_string);
	if ( size <= op1->size && !memcmp(op1->value.bytes, op->value.bytes, size) )
	   {	r_set_attrs(op1, a_subrange);
		*op = *op1;
		op->size = size;
		op1->value.bytes += size;
		op1->size -= size;
		push(1);
		make_bool(op, 1);
	   }
	else
		make_bool(op, 0);
	return 0;
}

/* search */
int
zsearch(register ref *op)
{	ref *op1 = op - 1;
	uint size = op->size;
	uint count;
	byte *ptr;
	check_read_type(*op1, t_string);
	check_read_type(*op, t_string);
	if ( size > op1->size )		/* can't match */
	   {	make_bool(op, 0);
		return 0;
	   }
	count = op1->size - size;
	ptr = op1->value.bytes;
	do
	   {	if ( !memcmp(ptr, op->value.bytes, size) )
		   {	op->type_attrs = op1->type_attrs;
			r_set_attrs(op, a_subrange);
			op->value.bytes = ptr;
			op->size = size;
			push(1);
			*op = *op1;
			op->size = ptr - op->value.bytes;
			op1->value.bytes = ptr + size;
			op1->size = count;
			push(1);
			make_bool(op, 1);
			return 0;
		   }
		ptr++;
	   }
	while ( count-- );
	/* No match */
	make_bool(op, 0);
	return 0;
}

/* token */
int
ztoken(register ref *op)
{	stream st;
	stream *s = &st;
	int code;
	ref token;
	switch ( r_type(op) )
	   {
	default: return e_typecheck;
	case t_file: return ztoken_file(op);
	case t_string: ;
	   }
	check_read(*op);
	sread_string(s, op->value.bytes, op->size);
	switch ( code = scan_token(s, 1, &token) )
	   {
	case 0:				/* read a token */
	   {	uint pos = stell(s);
		op->value.bytes += pos;
		op->size -= pos;
		r_set_attrs(op, a_subrange);
	   }
		push(2);
		op[-1] = token;
		make_bool(op, 1);
		return 0;
	case 1:				/* no tokens */
		make_bool(op, 0);
		return 0;
	default:			/* error */
		return code;
	   }
}

/* ------ Initialization procedure ------ */

void
zstring_op_init()
{	static op_def my_defs[] = {
		{"2anchorsearch", zanchorsearch},
		{"2search", zsearch},
		{"1string", zstring},
		{"1token", ztoken},
		op_def_end
	};
	z_op_init(my_defs);
}