/*
 *  Copyright (c) 1999-2003, Gene Cooperman; Rights to copy and distribute
 *  for non-commercial purposes only are freely granted, but only as
 *  long as this copyright statement remains.  No warranty is implied.
 */

final class Add extends BuiltInFunction {
    static final private String name = "+";
    static final private int numArgs = 2;
    SchemeObject function (SchemeObject arg1, SchemeObject arg2) {
        return new Fixnum( ((Fixnum)arg1).value + ((Fixnum)arg2).value );
    }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private Add() { super(name, numArgs); }
    private static final Add INSTANCE = new Add();
    static void install() { } // dummy function to force creation of class
}

final class Subtract extends BuiltInFunction {
    static final private String name = "-";
    static final private int numArgs = 2;
    SchemeObject function (SchemeObject arg1, SchemeObject arg2) {
        return new Fixnum( ((Fixnum)arg1).value - ((Fixnum)arg2).value );
    }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private Subtract() { super(name, numArgs); }
    private static final Subtract INSTANCE = new Subtract();
    static void install() { } // dummy function to force creation of class
}

final class SetBang extends SpecialFunction {
    static final private String name = "set!";
    static final private int numArgs = 2;
    SchemeObject function (SchemeObject arg1, SchemeObject arg2) {
	if ( ! (arg1 instanceof Symbol) )
	    throw new SchemeError("set!:  first arg is not a symbol");
	SchemeObject tmp = arg2.eval();
	((Symbol)arg1).setValue( tmp );
	return tmp;
    }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private SetBang() { super(name, numArgs); }
    private static final SetBang INSTANCE = new SetBang();
    static void install() { } // dummy function to force creation of class
}

final class Define extends SpecialFunction {
    static final private String name = "define";
    static final private int numArgs = 2;
    SchemeObject function (SchemeObject arg1, SchemeObject arg2) {
	if ( ! (arg1 instanceof Symbol) )
	    throw new SchemeError("define:  first arg is not a symbol");
	SchemeObject tmp = arg2.eval();
	((Symbol)arg1).setValue( tmp );
	return tmp;
    }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private Define() { super(name, numArgs); }
    private static final Define INSTANCE = new Define();
    static void install() { } // dummy function to force creation of class
}

final class Quote extends SpecialFunction {
    static private final String name = "quote";
    static private final int numArgs = 1;
    SchemeObject function (SchemeObject arg1) {
        return arg1;
    }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private static final Quote INSTANCE = new Quote();
    private Quote() { super(name, numArgs); }
    static void install() { } // dummy function to force creation of class
}

final class Eval extends BuiltInFunction {
    static private final String name = "eval";
    static private final int numArgs = 1;
    SchemeObject function (SchemeObject arg1) {
      try {
        return arg1.eval();
      } catch ( SchemeError se )
      { throw new Error("(eval " + arg1 + "): bad arg"); }
    }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private static final Eval INSTANCE = new Eval();
    private Eval() { super(name, numArgs); }
    static void install() { } // dummy function to force creation of class
}

final class Print extends BuiltInFunction {
    static private final String name = "print";
    static private final int numArgs = 1;
    SchemeObject function (SchemeObject arg1) {
	System.out.print( arg1 );
        return Symbol.schemeNil;
    }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private static final Print INSTANCE = new Print();
    private Print() { super(name, numArgs); }
    static void install() { } // dummy function to force creation of class
}

final class Exit extends BuiltInFunction {
    static private final String name = "exit";
    static private final int numArgs = 0;
    SchemeObject function () { System.exit(0); return null; }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private static final Exit INSTANCE = new Exit();
    private Exit() { super(name, numArgs); }
    static void install() { } // dummy function to force creation of class
}

final class EqualNumber extends BuiltInFunction {
    static private final String name = "=";
    static private final int numArgs = 2;
    SchemeObject function ( SchemeObject x, SchemeObject y ) {
	if ( ! (x instanceof Fixnum) || ! (y instanceof Fixnum) )
	    throw new SchemeError("=:  arguments must be fixnums");
	return ( ((Fixnum)x).value == ((Fixnum)y).value
		 ? Symbol.schemeTrue : Symbol.schemeFalse );
    }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private static final EqualNumber INSTANCE = new EqualNumber();
    private EqualNumber() { super(name, numArgs); }
    static void install() { } // dummy function to force creation of class
}

// To generalize to if with 2 or 3 args, set numArgs to -1
final class If extends SpecialFunction {
    static private final String name = "if";
    static private final int numArgs = -1;
    SchemeObject function ( SchemeObject args ) {
	if ( args.length() < 2 || args.length() > 3 )
	    throw new SchemeError("if:  Called with " + args.length() +
				  " args; should be called with 2 or 3 args");
	if ( args.car().eval() == Symbol.schemeTrue )
	    return args.cdr().car().eval();
	else if ( args.cdr().cdr() != Symbol.schemeNil )
	    return args.cdr().cdr().car().eval();
	else
	    return Symbol.schemeFalse;
    }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private static final If INSTANCE = new If();
    private If() { super(name, numArgs); }
    static void install() { } // dummy function to force creation of class
}

final class Lambda extends SpecialFunction {
    static private final String name = "lambda";
    static private final int numArgs = -1;
    SchemeObject function (SchemeObject arg1) {
        return new LambdaSymbol(arg1.car(), arg1.cdr());
    	//return LambdaFnc.function(arg1);
    }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private static final Lambda INSTANCE = new Lambda();
    private Lambda() { super(name, numArgs); }
    static void install() { } // dummy function to force creation of class
}

final class LambdaFnc extends BuiltInFunction {
    static private String name = "lambdafnc";
    static private int numArgs = -1;
    private SchemeObject arg = null;
    private SchemeObject body = null;

    SchemeObject function (SchemeObject args) {
    	this.arg = args.car();
    	this.body = args.cdr();
    	System.out.println("lf "+arg+" "+body);
        return new LambdaSymbol(arg, body);
    }

    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private static final LambdaFnc INSTANCE = new LambdaFnc();
    private LambdaFnc() { super(name, numArgs); }
    static void install() { } // dummy function to force creation of class
}
/*
final class LambdaBegin extends OrdinaryFunction {
    static private final String name = "lambdabegin";
    static private final int numArgs = 1;
    protected SchemeObject value = null;
    SchemeObject function (SchemeObject arg1) {
    	System.out.println("LambdaBegin called "+arg1);
    	this.value = arg1;
        return arg1;
    }
    
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private static final LambdaBegin INSTANCE = new LambdaBegin();
    private LambdaBegin() { super(name, numArgs); }
    static void install() { } // dummy function to force creation of class
}
//*/
final class Eq extends BuiltInFunction {
    static final private String name = "eq?";
    static final private int numArgs = 2;
    SchemeObject function (SchemeObject arg1, SchemeObject arg2) {
    	if (arg1 == arg2)
    		return Symbol.schemeTrue;
    	else
    		return Symbol.schemeFalse;
    }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private Eq() { super(name, numArgs); }
    private static final Eq INSTANCE = new Eq();
    static void install() { } // dummy function to force creation of class
}

final class Begin extends BuiltInFunction {
    static final private String name = "begin";
    static final private int numArgs = -1;
    SchemeObject function (SchemeObject args) {
    	SchemeObject returnval = null;
    	int i = 0;
    	while(i < args.length()) {
    		returnval = args.nth(i).eval();
    		i++;
    	}
    	i--;
    	return returnval;
    }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private Begin() { super(name, numArgs); }
    private static final Begin INSTANCE = new Begin();
    static void install() { } // dummy function to force creation of class
}

final class GreaterNumber extends BuiltInFunction {
    static private final String name = ">";
    static private final int numArgs = 2;
    SchemeObject function ( SchemeObject x, SchemeObject y ) {
	if ( ! (x instanceof Fixnum) || ! (y instanceof Fixnum) )
	    throw new SchemeError(">:  arguments must be fixnums");
	return ( ((Fixnum)x).value > ((Fixnum)y).value
		 ? Symbol.schemeTrue : Symbol.schemeFalse );
    }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private static final GreaterNumber INSTANCE = new GreaterNumber();
    private GreaterNumber() { super(name, numArgs); }
    static void install() { } // dummy function to force creation of class
}

final class Car extends SpecialFunction {
    static private final String name = "car";
    static private final int numArgs = 1;
    SchemeObject function ( SchemeObject arg ) {
    	return arg.car();
    }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private static final Car INSTANCE = new Car();
    private Car() { super(name, numArgs); }
    static void install() { } // dummy function to force creation of class
}

final class Cdr extends SpecialFunction {
    static private final String name = "cdr";
    static private final int numArgs = 1;
    SchemeObject function ( SchemeObject arg ) {
    	return arg.cdr();
    }
    // Ordering important.  Define name, numArgs before super(name, numArgs)
    private static final Cdr INSTANCE = new Cdr();
    private Cdr() { super(name, numArgs); }
    static void install() { } // dummy function to force creation of class
}