#define GCSTACKSIZE 256

typedef union Trie Trie;
#pragma incomplete Trie

typedef struct aaContext aaContext;
typedef struct aaHandlers aaHandlers;
typedef struct aaNumber aaNumber;
typedef struct aaObject aaObject;

typedef union aaValue aaValue;

typedef aaObject *(*aaCFunc)(aaContext *ctx, aaObject *args);
typedef void (*aaErrorFn)(aaContext *ctx, const char *err, aaObject *cl);
typedef char (*aaReadFn)(aaContext *ctx, void *udata);

struct aaNumber {
	double r;
	//double i;
};
//#define aNumber(r,i) (aaNumber){r, i}
#define aNumber(r,i) (aaNumber){r}

union aaValue {
	Biobuf *port;
	aaObject *o;
	aaCFunc f;
	aaNumber n;
	char c;
};

struct aaObject {
	aaValue car;
	aaValue cdr;
};

struct aaHandlers {
	aaErrorFn error;
	aaCFunc mark;
	aaCFunc gc;
};

struct aaContext {
	aaHandlers handlers;
	aaObject *gcstack[GCSTACKSIZE];
	int gcstack_idx;
	aaObject *objects;
	int object_count;
	aaObject *calllist;
	aaObject *freelist;
	aaObject *symlist;
	Trie *symtrie;
	aaObject *t;
	Rune nextrune;

	Biobuf *fd[3];
};

enum {
	AA_TPAIR,
	AA_TFREE,
	AA_TNUMBER,
	AA_TSYMBOL,
	AA_TSTRING,
	AA_TFUNC,
	AA_TMACRO,
	AA_TPRIM,
	AA_TCFUNC,
	AA_TPTR,
	AA_TBOOL,
	AA_TPORT,

	AA_TMAX,

	AA_NOSTDIO = 1<<0,
};

extern aaObject Null;
extern aaObject False;
extern aaObject True;

#pragma varargck argpos aa_error 2
#pragma varargck type "ß" aaObject*
#pragma varargck type "§" aaObject*

aaContext *aa_open(void *ptr, int size, int flags);
void aa_close(aaContext *ctx);
aaHandlers *aa_handlers(aaContext *ctx);
void aa_error(aaContext *ctx, const char *fmt, ...);
aaObject *aa_nextarg(aaContext *ctx, aaObject **arg, int optional);
int aa_type(aaContext *ctx, aaObject *obj);
void aa_pushgc(aaContext *ctx, aaObject *obj);
void aa_restoregc(aaContext *ctx, int idx);
int aa_savegc(aaContext *ctx);
void aa_mark(aaContext *ctx, aaObject *obj);
aaObject *aa_cons(aaContext *ctx, aaObject *car, aaObject *cdr);
aaObject *aa_bool(aaContext *ctx, int b);
aaObject *aa_number(aaContext *ctx, aaNumber n);
aaObject *aa_string(aaContext *ctx, const char *str);
aaObject *aa_symbol_find(aaContext *ctx, const char *name);
aaObject *aa_symbol(aaContext *ctx, const char *name);
aaObject *aa_cfunc(aaContext *ctx, aaCFunc fn);
aaObject *aa_ptr(aaContext *ctx, void *ptr);
aaObject *aa_list(aaContext *ctx, aaObject **objs, int n);
aaObject *aa_car(aaContext *ctx, aaObject *obj);
aaObject *aa_cdr(aaContext *ctx, aaObject *obj);
aaNumber aa_tonumber(aaContext *ctx, aaObject *obj);
void *aa_toptr(aaContext *ctx, aaObject *obj);
void aa_set(aaContext *ctx, aaObject *sym, aaObject *v);
aaObject *aa_read(aaContext *ctx, Biobuf *fp);
aaObject *aa_eval(aaContext *ctx, aaObject *obj);