# ifndef functionh
# define functionh

# include "environment.h"

class ListNode;

class Function : public Expression {
public:
	virtual Function * isFunction();

	virtual void apply(Expr &, ListNode *, Environment *);
	virtual void applyWithArgs(Expr &, ListNode *, Environment *);
	virtual void print();

	// isClosure is recognized only by functions
	virtual int isClosure();
};

class UnaryFunction : public Function {
private:
	void (*fun)(Expr &, Expression *);
public:
	UnaryFunction() { fun = 0; }
	UnaryFunction(void (*afun)(Expr &, Expression *))
		{ fun = afun; }
	virtual void apply(Expr &, ListNode *, Environment *);
	virtual void applyWithArgs(Expr &, ListNode *, Environment *);
};

class BinaryFunction : public Function {
private:
	void (*fun)(Expr &, Expression *, Expression *);
public:
	BinaryFunction() { fun = 0; }
	BinaryFunction(void (*afun)(Expr &, Expression *, Expression *))
		{ fun = afun; }
	virtual void apply(Expr &, ListNode *, Environment *);
	virtual void applyWithArgs(Expr &, ListNode *, Environment *);
};

class IntegerBinaryFunction : public BinaryFunction {
private:
	int (*fun)(int, int);
public:
	IntegerBinaryFunction(int (*thefun)(int, int))
		{ fun = thefun; }
	virtual void applyWithArgs(Expr &, ListNode *, Environment *);
};

class BooleanBinaryFunction : public BinaryFunction {
private:
	int (*fun)(int, int);
public:
	BooleanBinaryFunction(int (*thefun)(int, int))
		{ fun = thefun; }
	virtual void applyWithArgs(Expr &, ListNode *, Environment *);
};

class UserFunction : public Function {
protected:
	List argNames;
	Expr body;
	Env context;
public:
	UserFunction(ListNode *, Expression *, Environment *);
	virtual void free();
	virtual void applyWithArgs(Expr &, ListNode *, Environment *);
	virtual int isClosure();
};

# endif