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/*
 * Copyright (c) 2013, SRI International
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 * Licensed under the The BSD 3-Clause License;
 * you may not use this file except in compliance with the License.
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package com.sri.ai.grinder.sgdpll.simplifier.api;

import static com.sri.ai.util.Util.putAll;

import java.util.Map;

import com.google.common.annotations.Beta;
import com.sri.ai.expresso.api.Expression;
import com.sri.ai.grinder.api.Context;
import com.sri.ai.grinder.sgdpll.simplifier.core.DefaultMapBasedTopSimplifier;
import com.sri.ai.grinder.sgdpll.simplifier.core.RecursiveExhaustiveMapBasedSimplifier;
import com.sri.ai.util.collect.StackedHashMap;

@Beta
/** 
 * An type of {@link Simplifier} based on maps from functor or syntactic form types to
 * elementary simplifiers in the form of {@link BinaryFunction}s
 * from an {@link Expression} and {@link Context} to an {@link Expression},
 * which are applied exhaustively, in a top-down manner, to expressions to be simplified. 
 */
public interface MapBasedSimplifier extends Simplifier {

	Map getFunctionApplicationSimplifiers();

	Map getSyntacticFormTypeSimplifiers();

	/**
	 * Returns a top simplifier constructed from this {@link MapBasedSimplifier}'s
	 * elementary function and syntactic form type simplifiers.
	 * @return
	 */
	default TopSimplifier getTopSimplifier() {
		DefaultMapBasedTopSimplifier topSimplifier = 
				new DefaultMapBasedTopSimplifier(
						getFunctionApplicationSimplifiers(),
						getSyntacticFormTypeSimplifiers());
		return topSimplifier;
	}
	
	/**
	 * Simplify an expression given maps of function application and syntactic form type simplifiers,
	 * and an extra simplifier for a given syntactic form type.
	 * @param expression
	 * @param functionApplicationSimplifiers
	 * @param syntacticFormTypeSimplifiers
	 * @param context
	 * @param additionalSyntacticFormTypesAndSimplifiers additional syntactic form types and corresponding simplifiers
	 * @return
	 */
	public static Expression simplifyWithExtraSyntacticFormTypeSimplifiers(
			Expression expression,
			Map functionApplicationSimplifiers, Map syntacticFormTypeSimplifiers,
			Context context,
			Object... additionalSyntacticFormTypesAndSimplifiers) {
		
		Map
		mySyntacticFormTypeSimplifiers = new StackedHashMap(syntacticFormTypeSimplifiers);
		
		putAll(mySyntacticFormTypeSimplifiers, additionalSyntacticFormTypesAndSimplifiers);
		
		Expression result = simplify(expression, functionApplicationSimplifiers, mySyntacticFormTypeSimplifiers, context);
		return result;
	}

	/**
	 * Simplifies an expression based on two maps of simplifiers by creating an instance of {@link RecursiveExhaustiveMapBasedSimplifier}
	 * with them and applies it to the expression.
	 * @param expression
	 * @param functionApplicationSimplifiers
	 * @param syntacticFormSimplifiers
	 * @param context
	 * @return
	 */
	public static Expression simplify(Expression expression, Map functionApplicationSimplifiers, Map syntacticFormSimplifiers, Context context) {
		RecursiveExhaustiveMapBasedSimplifier simplifier = new RecursiveExhaustiveMapBasedSimplifier(functionApplicationSimplifiers, syntacticFormSimplifiers);
		Expression result = simplifier.apply(expression, context);
		return result;
	}
}