/*
 *	aegis - project change supervisor
 *	Copyright (C) 1997 Peter Miller;
 *	All rights reserved.
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 *	This program is distributed in the hope that it will be useful,
 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *	GNU General Public License for more details.
 *
 *	You should have received a copy of the GNU General Public License
 *	along with this program; if not, write to the Free Software
 *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 *
 * MANIFEST: functions to manipulate constant tree nodes
 */

#include <ac/stdio.h>

#include <aer/value/string.h>
#include <str.h>
#include <tree/constant.h>
#include <tree/private.h>


typedef struct tree_constant_ty tree_constant_ty;
struct tree_constant_ty
{
	tree_ty		inherited;
	rpt_value_ty	*value;
};


static void destructor _((tree_ty *));

static void
destructor(tp)
	tree_ty		*tp;
{
	tree_constant_ty	*this;

	this = (tree_constant_ty *)tp;
	rpt_value_free(this->value);
}


static void print _((tree_ty *));

static void
print(tp)
	tree_ty		*tp;
{
	tree_constant_ty *this;
	rpt_value_ty	*vp;

	this = (tree_constant_ty *)tp;
	vp = rpt_value_stringize(this->value);
	printf("'%s'", rpt_value_string_query(vp)->str_text);
	rpt_value_free(vp);
}


static rpt_value_ty *evaluate _((tree_ty *, string_ty *, struct stat *));

static rpt_value_ty *
evaluate(tp, path, st)
	tree_ty		*tp;
	string_ty	*path;
	struct stat	*st;
{
	tree_constant_ty *this;

	this = (tree_constant_ty *)tp;
	return rpt_value_copy(this->value);
}


static int useful _((tree_ty *));

static int
useful(tp)
	tree_ty		*tp;
{
	return 0;
}


static int constant _((tree_ty *));

static int
constant(tp)
	tree_ty		*tp;
{
	return 1;
}


static tree_method_ty method =
{
	sizeof(tree_constant_ty),
	"constant",
	destructor,
	print,
	evaluate,
	useful,
	constant,
	0, /* optimize */
};


tree_ty *
tree_constant_new(value)
	rpt_value_ty	*value;
{
	tree_ty		*tp;
	tree_constant_ty *this;

	tp = tree_new(&method);
	this = (tree_constant_ty *)tp;
	this->value = rpt_value_copy(value);
	return tp;
}