package lambdaKit.model.util;

import lambdaKit.model.term.Abstraction;
import lambdaKit.model.type.FunctionType;

/*
 * The TypeAssigner assigns types to combinators, à la Curry.
 * 
 * If the combinator A is typed by (T1 -> T2)
 * 	and the combinator B is typed by T1
 *  then the combinator AB is typed by T2.
 */
public interface TypeAssigner {

	/*
	 * Assigns a FunctionType to a combinator and returns this FunctionType.
	 * Returns null if the combinator cannot be typed, such as "λa.aa".
	 */
	public FunctionType assignType(Abstraction combinatorHand);
}