#ifndef value_h
#define value_h

#include "intern.h"
#include "env.h"
#include "syntax.h"
#include "builtins.h"
#include <stdbool.h>
typedef struct env env_t;
typedef struct value value_t;
typedef struct gc gc_t;



struct value {
  enum {
    VALUE_INT = 0,
    VALUE_FLOAT,
    VALUE_STRING,
    VALUE_CONSTRUCTOR,
    VALUE_CLOSURE,
    VALUE_BUILTIN,
    VALUE_ENV,
  } tag;
  union {
    long integer;
    double floating;
    builtin_func_t *builtin;
    struct {
      char *string;
      bool shared;
    } string;
    struct {
      intern_t name;
      value_t **args;
      size_t num_args;
    } constructor;
    struct {
      value_t *env;
      expr_t *body;
      size_t arity;
      value_t *next; // should be another closure of the same arity
    } closure;
    env_t *env;
  } as;
  value_t *gc_next;
};


/* allocate a gc arena */
gc_t *gc_alloc(void);

/* free a gc arena -- ensure all values are collected first */
void gc_free(gc_t *);

/* Allocation */
value_t *value_alloc(gc_t *gc);

value_t *value_alloc_bool(gc_t *gc, bool);
value_t *value_alloc_int(gc_t *gc, long);
value_t *value_alloc_float(gc_t *gc, double);
value_t *value_alloc_string(gc_t *gc, char *, bool shared);

/* Mark as live for gc */
void value_mark_gc(value_t *);

/* GC collection */
void gc(gc_t *gc);

void value_debug_dump(value_t *it);

#endif