/* Copyright (C) 1989, 1995 Aladdin Enterprises.  All rights reserved.
  
  This file is part of GNU Ghostscript.
  
  GNU 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 GNU Ghostscript General Public License for full details.
  
*/

/* zstring.c */
/* String operators */
#include "memory_.h"
#include "ghost.h"
#include "errors.h"
#include "gsutil.h"
#include "ialloc.h"
#include "iname.h"
#include "ivmspace.h"
#include "oper.h"
#include "store.h"

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

/* <int> string <string> */
int
zstring(register os_ptr op)
{	byte *sbody;
	uint size;
	check_int_leu(*op, max_string_size);
	size = op->value.intval;
	sbody = ialloc_string(size, "string");
	if ( sbody == 0 )
	  return_error(e_VMerror);
	make_string(op, a_all | icurrent_space, size, sbody);
	memset(sbody, 0, size);
	return 0;
}

/* <name> .namestring <string> */
private int
znamestring(register os_ptr op)
{	check_type(*op, t_name);
	name_string_ref(op, op);
	return 0;
}

/* <string> <pattern> anchorsearch <post> <match> -true- */
/* <string> <pattern> anchorsearch <string> -false- */
private int
zanchorsearch(register os_ptr op)
{	os_ptr op1 = op - 1;
	uint size = r_size(op);
	check_read_type(*op1, t_string);
	check_read_type(*op, t_string);
	if ( size <= r_size(op1) && !memcmp(op1->value.bytes, op->value.bytes, size) )
	{	os_ptr op0 = op;
		push(1);
		*op0 = *op1;
		r_set_size(op0, size);
		op1->value.bytes += size;
		r_dec_size(op1, size);
		make_true(op);
	}
	else
		make_false(op);
	return 0;
}

/* <string> <pattern> search <post> <match> <pre> -true- */
/* <string> <pattern> search <string> -false- */
private int
zsearch(register os_ptr op)
{	os_ptr op1 = op - 1;
	uint size = r_size(op);
	uint count;
	byte *ptr;
	check_read_type(*op1, t_string);
	check_read_type(*op, t_string);
	if ( size > r_size(op1) )		/* can't match */
	   {	make_false(op);
		return 0;
	   }
	count = r_size(op1) - size;
	ptr = op1->value.bytes;
	do
	   {	if ( !memcmp(ptr, op->value.bytes, size) )
		   {	op->tas.type_attrs = op1->tas.type_attrs;
			op->value.bytes = ptr;
			r_set_size(op, size);
			push(2);
			op[-1] = *op1;
			r_set_size(op - 1, ptr - op[-1].value.bytes);
			op1->value.bytes = ptr + size;
			r_set_size(op1, count);
			make_true(op);
			return 0;
		   }
		ptr++;
	   }
	while ( count-- );
	/* No match */
	make_false(op);
	return 0;
}

/* <obj> <pattern> .stringmatch <bool> */
private int
zstringmatch(register os_ptr op)
{	os_ptr op1 = op - 1;
	bool result;
	check_read_type(*op, t_string);
	switch ( r_type(op1) )
	   {
	case t_string:
		check_read(*op1);
		goto cmp;
	case t_name:
		name_string_ref(op1, op1);		/* can't fail */
cmp:		result = string_match(op1->value.const_bytes, r_size(op1),
				      op->value.const_bytes, r_size(op),
				      NULL);
		break;
	default:
		result = (r_size(op) == 1 && *op->value.bytes == '*');
	   }
	make_bool(op1, result);
	pop(1);
	return 0;
}

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

BEGIN_OP_DEFS(zstring_op_defs) {
	{"2anchorsearch", zanchorsearch},
	{"1.namestring", znamestring},
	{"2search", zsearch},
	{"1string", zstring},
	{"2.stringmatch", zstringmatch},
END_OP_DEFS(0) }
