Refactored the built in function quote

src/function/builtin/special/QUOTE.java

@@ -1,41 +1,23 @@
 package function.builtin.special;
 
-import function.LispFunction;
-import function.builtin.cons.LENGTH;
+import function.*;
 import sexpression.*;
 
-/**
- * <code>QUOTE</code> represents the QUOTE form in Lisp.
- */
 public class QUOTE extends LispFunction {
 
-    // The number of arguments that QUOTE takes.
-    private static final int NUM_ARGS = 1;
+    private ArgumentValidator argumentValidator;
 
-    public SExpression call(Cons argList) {
-        // retrieve the number of arguments passed to QUOTE
-        int argListLength = LENGTH.getLength(argList);
-
-        // make sure we have received exactly one argument
-        if (argListLength != NUM_ARGS) {
-            Cons originalSExpr = new Cons(new Symbol("QUOTE"), argList);
-            String errMsg = "too " +
-                            ((argListLength > NUM_ARGS) ? "many" : "few") +
-                            " arguments given to QUOTE: " + originalSExpr;
-
-            throw new RuntimeException(errMsg);
-        }
-
-        return argList.getCar();
+    public QUOTE() {
+        this.argumentValidator = new ArgumentValidator("QUOTE");
+        this.argumentValidator.setExactNumberOfArguments(1);
+    }
+
+    public SExpression call(Cons argumentList) {
+        argumentValidator.validate(argumentList);
+
+        return argumentList.getCar();
     }
 
-    /**
-     * Determine if the arguments passed to this Lisp function should be
-     * evaluated.
-     *
-     * @return
-     *  <code>false</code>
-     */
     public boolean evaluateArguments() {
         return false;
     }