FunctionTypeFinder.java

/*
 * #%~
 * The VDM Type Checker
 * %%
 * Copyright (C) 2008 - 2014 Overture
 * %%
 * 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 3 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, see
 * <http://www.gnu.org/licenses/gpl-3.0.html>.
 * #~%
 */
package org.overture.typechecker.utilities.type;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Vector;

import org.overture.ast.analysis.AnalysisException;
import org.overture.ast.analysis.AnswerAdaptor;
import org.overture.ast.assistant.pattern.PTypeList;
import org.overture.ast.definitions.PDefinition;
import org.overture.ast.factory.AstFactory;
import org.overture.ast.node.INode;
import org.overture.ast.node.NodeList;
import org.overture.ast.types.ABracketType;
import org.overture.ast.types.AFunctionType;
import org.overture.ast.types.ANamedInvariantType;
import org.overture.ast.types.AOptionalType;
import org.overture.ast.types.AUnionType;
import org.overture.ast.types.AUnknownType;
import org.overture.ast.types.PType;
import org.overture.ast.types.SInvariantType;
import org.overture.ast.util.PTypeSet;
import org.overture.typechecker.assistant.ITypeCheckerAssistantFactory;

/**
 * Used to get a Function type from a type
 * 
 * @author kel
 */
public class FunctionTypeFinder extends AnswerAdaptor<AFunctionType>
{
	protected ITypeCheckerAssistantFactory af;

	public FunctionTypeFinder(ITypeCheckerAssistantFactory af)
	{
		this.af = af;
	}

	@Override
	public AFunctionType caseABracketType(ABracketType type)
			throws AnalysisException
	{
		return type.getType().apply(THIS);
	}

	@Override
	public AFunctionType caseANamedInvariantType(ANamedInvariantType type)
			throws AnalysisException
	{
		return type.getType().apply(THIS);
	}

	@Override
	public AFunctionType defaultSInvariantType(SInvariantType type)
			throws AnalysisException
	{
		return null;
	}

	@Override
	public AFunctionType caseAFunctionType(AFunctionType type)
			throws AnalysisException
	{
		return type;
	}

	@Override
	public AFunctionType caseAOptionalType(AOptionalType type)
			throws AnalysisException
	{

		return type.getType().apply(THIS);
	}

	@Override
	public AFunctionType caseAUnionType(AUnionType type)
			throws AnalysisException
	{

		if (!type.getFuncDone())
		{
			type.setFuncDone(true);
			type.setFuncType(af.createPTypeAssistant().getFunction(AstFactory.newAUnknownType(type.getLocation())));

			PTypeSet result = new PTypeSet(af);
			Map<Integer, PTypeSet> params = new HashMap<Integer, PTypeSet>();
			List<PDefinition> defs = new Vector<PDefinition>();

			for (PType t : type.getTypes())
			{
				if (af.createPTypeAssistant().isFunction(t))
				{
					if (t.getDefinitions() != null)
					{
						defs.addAll(t.getDefinitions());

						AFunctionType f = af.createPTypeAssistant().getFunction(t);
						result.add(f.getResult());

						for (int p = 0; p < f.getParameters().size(); p++)
						{
							PType pt = f.getParameters().get(p);
							PTypeSet pset = params.get(p);

							if (pset == null)
							{
								pset = new PTypeSet(pt, af);
								params.put(p, pset);
							} else
							{
								pset.add(pt);
							}
						}
					}
				}

				if (!result.isEmpty())
				{
					PType rtype = result.getType(type.getLocation());
					PTypeList plist = new PTypeList();

					for (int i = 0; i < params.size(); i++)
					{
						PType pt = params.get(i).getType(type.getLocation());
						plist.add(pt);
					}

					type.setFuncType(AstFactory.newAFunctionType(type.getLocation(), true, plist, rtype));
					type.getFuncType().setDefinitions(defs);
				} else
				{
					type.setFuncType(null);
				}
			}
		}
		return (AFunctionType) type.getFuncType();
	}

	@Override
	public AFunctionType caseAUnknownType(AUnknownType type)
			throws AnalysisException
	{

		return AstFactory.newAFunctionType(type.getLocation(), true, new NodeList<PType>(null), AstFactory.newAUnknownType(type.getLocation()));
	}

	@Override
	public AFunctionType createNewReturnValue(INode node)
			throws AnalysisException
	{
		assert false : "Can't getFunction of a non-function";
		return null;
	}

	@Override
	public AFunctionType createNewReturnValue(Object node)
			throws AnalysisException
	{
		assert false : "Can't getFunction of a non-function";
		return null;
	}

}