/*
 *  This file is part of the X10 project (http://x10-lang.org).
 *
 *  This file is licensed to You under the Eclipse Public License (EPL);
 *  You may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *      http://www.opensource.org/licenses/eclipse-1.0.php
 *
 *  (C) Copyright IBM Corporation 2006-2010.
 */

package x10.types;

import java.util.List;

import polyglot.types.LocalInstance;
import polyglot.types.Type;
import x10.types.constraints.CConstraint;

/**
 * The type of a function interface, representing the function's signature
 * (argument types, return type, guard).
 */
public interface FunctionType extends X10ParsedClassType {
    MethodInstance applyMethod();

    /**
     * Return the type of value returned by an invocation of the closure. cannot be void.
     */
    Type returnType();

    /**
     * Return the list of formal type arguments of the closure, in declaration order. may be empty.
     * Note: This differs from typeArguments, inherited from X10ClassType.
     * For [S](T) => U, 
     * the class type for the closure is Fun_1_1[T,U].
     * typeParameters is [S] and argumentTypes is (T).  typeArguments is [T,U].
     */
    List<Type> typeParameters();

    /**
     * @return the list of formal value argument types of the closure, in declaration order. may be empty.
     */
    List<Type> argumentTypes();

    /**
     * @return the list of formal value argument names of the closure, in declaration order. may be empty.
     */
    List<LocalInstance> formalNames();
    
    /**
     * @return the guard for the closure.
     */
    CConstraint guard();

//    public FunctionType returnType(Type l);
//
//    public FunctionType guard(XConstraint l);
//
//    public FuntcionType typeParameters(List<Type> l);
//
//    public FunctionType argumentTypes(List<Type> l);
}