#ifndef EVAL_H_
#define EVAL_H_
#include "sexp.h"
struct env {
struct atom *name;
struct value *value;
struct env *next;
};
struct value *lookup(struct env *, struct atom *);
struct env *bind(struct env *, struct atom *, struct value *);
struct value *eval(struct value *, struct env *);
#endif /* !EVAL_H_ */