#ifndef _VAE_H
#define _VAE_H

#include "va.h"

typedef Value (*Function)(Value);

void VA__INIT(void);

typedef enum { NILAD, MONAD, DYAD, TRIAD } Arity;

typedef struct {
  char *name;
  Arity arity;
  Function function;
} ExternalFunction;

typedef enum { FUNCTION, VARIABLE } ExternalType;

typedef struct {
  ExternalFunction function;
  ExternalType type;
} External;

#define FUNDEF(n) \
Value n(Value args) { \
  Value x, y, z; \
  x = y = z = Nil; \
  switch (lenof(args)) { \
    case 1: x = FIRST(args); break; \
    case 2: x = FIRST(args); y = SECOND(args); break; \
    case 3: x = FIRST(args); y = SECOND(args); z = THIRD(args); break; \
  }

#define FUN(n, a, f) {{n, a, f}, FUNCTION}
#define VAR(n, v) {{n, 0, v}, VARIABLE}
#define VARSET(n, v) Value n(Value _N_) { return (v); }
#define INIT void VA__INIT(void)
#define EXPORT(c) int __VA_EXPORTED__ = c; External __VA_EXPORT__[c] = 
#endif