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Functional patterns for Java

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package com.jnape.palatable.lambda.functor;

import com.jnape.palatable.lambda.functions.Fn1;

/**
 * The contravariant functor (or "co-functor"); that is, a functor that maps contravariantly (A <- B)
 * over its parameter.
 * Contravariant functors are not necessarily {@link Functor}s.
 * 
 * For more information, read about
 * Contravariant Functors.
 *
 * @param  the type of the parameter
 * @param  the unification parameter
 * @see Profunctor
 */
public interface Contravariant> {

    /**
     * Contravariantly map A <- B.
     *
     * @param fn  the mapping function
     * @param  the new parameter type
     * @return the mapped Contravariant functor instance
     */
     Contravariant contraMap(Fn1 fn);
}