// Primitive and Special Function Object Code.
//
// File:        function.cc
// Author:      {your name} <{your e-mail address}>
// Assignment:  9

#include "function.h"
#include "obtype.h"
#include "gc.h"
#include "symbol.h"

class function_type : public object_type
{

public:

    function_type () : object_type ("FUNCTION") {}
	// Construct object type with simple free and
	// used lists and the name "FUNCTION".

    virtual void initialize();
	// Initialize LAMBDA, LAMBDA_CLOSURE, MACRO,
	// etc.

    friend function * make_function
	    (c_function cfun, bool special);
};

object_type * FUNCTION_TYPE =
    (object_type *) new function_type;

// Create a function with a C++ function and special
// indicator.
//
function * make_function (c_function cfun, bool special)
{
    function * f;

    // ***** Put gc code here for assignment 9 ***** 

    object * ob;
    if (ob = FUNCTION_TYPE->get_free())
	    f = (function *) ob;
    else    f = new function;

    f->init_object (FUNCTION_TYPE);
    f->cfun		= cfun;
    f->special	= special;
    FUNCTION_TYPE->put_used (f);
    return f;
}

object * LAMBDA;
object * LAMBDA_CLOSURE;
object * MACRO;
object * REST;
object * OPTIONAL;

// Initialize LAMBDA, LAMBDA_CLOSURE, MACRO, etc.
//
void function_type::initialize()
{
    LAMBDA = make_symbol ("LAMBDA");
    LAMBDA_CLOSURE = make_symbol ("LAMBDA-CLOSURE");
    MACRO = make_symbol ("MACRO");
    REST = make_symbol ("&REST");
    OPTIONAL = make_symbol ("&OPTIONAL");
}

// Print function.
//
ostream& function::print (ostream& s)
{
    return s <<
	( specialp(this) ? "#<special function>"
			 : "#<primitive function>" );
}

// Scavenge function.
//
void function::scavenge() {}