/*
 * Name: Mike Cifelli
 * Course: CIS 443 - Programming Languages
 * Assignment: Lisp Interpreter 1
 */

package eval;

import parser.*;

/**
 * A <code>LispFunction</code> is an internal representation of a built-in
 * function in the Lisp programming language.
 */
public abstract class LispFunction {

    /**
     * Call this Lisp function with the given list of arguments.
     *
     * @param argList
     *  the list of arguments to pass to this function (MUST BE A PROPER LIST)
     * @return
     *  the resulting S-expression of calling this function with the specified
     *  arguments
     * @throws RuntimeException
     *  Indicates that an incorrect number of arguments has been passed to this
     *  function or that one of the arguments is not of the expected type.
     */
    public abstract SExpression call(Cons argList);

    /**
     * Determine if the arguments passed to this Lisp function should be
     * evaluated. A subclass should override this method to return
     * <code>false</code> if it does not want its arguments to be evaluated
     * prior to being passed.
     *
     * @return
     *  <code>true</code>
     */
    public boolean evaluateArguments() {
        return true;
    }

}