enum {
	/* size of argument arrays, uses Maxarg * sizeof(Node*) stack per call */
	Maxarg		= 16,
};

typedef struct Gc	Gc;
typedef struct List	List;
typedef struct Lsym	Lsym;
typedef struct Metatable Metatable;
typedef struct Node	Node;
typedef struct Pointer Pointer;
typedef struct Rplace	Rplace;
typedef struct Store	Store;
typedef struct Strc	Strc;
typedef struct String	String;
typedef struct Value	Value;

#pragma incomplete List
#pragma incomplete Value

enum {
	/* Gc.mark */
	GCMARK	= 1,
	/* Gc.flag */
	GCMETA	= GCMARK<<1,
	GCPIN	= GCMETA<<1,
};

struct Gc
{
	Gc*	link;
	unsigned char	mark;
	unsigned char	flag;
	unsigned short	type;
};

struct String
{
	Gc		gc;
	char	*string;
	int		len;
};

struct Lsym
{
	char*	name;
	int		lexval;
	Lsym*	hash;
	Value*	v;
	Node*	proc;
	void	(*builtin)(Node*, Node**, int);
};

struct Pointer
{
	Gc			gc;
	Metatable	*meta;
	void		*v;
};

/* Store.type */
enum
{
	TINT,
	TFLOAT,
	TSTRING,
	TLIST,
	TCODE,
	TPOINTER,
	TMAX,
};

struct Store
{
	uchar	type;
	union {
		vlong	ival;
		double	fval;
		String*	string;
		List*	l;
		Node*	cc;
		Pointer *pval;
	};
};

struct List
{
	Gc		gc;
	List*	next;
	Store	store;
};

/* Node.op */
enum
{
	OINVALID,
	ONAME,
	OCONST,
	OMUL,
	ODIV,
	OMOD,
	OADD,
	OSUB,
	ORSH,
	OLSH,
	OLT,
	OGT,
	OLEQ,
	OGEQ,
	OEQ,
	ONEQ,
	OLAND,
	OXOR,
	OLOR,
	OCAND,
	OCOR,
	OASGN,
	OINDM,
	OEDEC,
	OEINC,
	OPINC,
	OPDEC,
	ONOT,
	OIF,
	ODO,
	OFOR,
	OBREAK,
	OCONTINUE,
	OLIST,
	OCALL,
	OCTRUCT,
	OWHILE,
	OELSE,
	OHEAD,
	OTAIL,
	OAPPEND2,
	ORET,
	OINDEX,
	OINDC,
	ODOT,
	OLOCAL,
	ODELETE,
	OCAST,
	OEVAL,
	OWHAT,
};

struct Node
{
	Gc		gc;
	uchar	op;
	Node*	left;
	Node*	right;
	Lsym*	sym;
	int	builtin;
	Store	store;
};

#define ZN	(Node*)0

/*
	possible future lua-isms

	index, newindex, mode, call, metatable,
	tostring, len, pairs, ipairs, gc
	unm, add, sub, mul, div, idiv, mod, pow, concat
	band, bor, bxor, bnot, shl, shr
	eq, lt, le
*/
struct Metatable
{
	void	(*index)(Node *v, char *nam, Node *res);
	void	(*newindex)(Node *v, char *nam, Node *arg);
	void	(*gc)(Pointer *v);
};

void	ppsetup(void);
void	ppdestroy(void);
void	pppin(Node*);
void	ppunpin(Node*);

void	ppinput(void);
void	ppbind(char*, void (*)(Node*, Node**, int));
int		ppcall(char*, Node*, Node*);
void	ppcheckarg(Node **av, int na, int i, int type, Node *res);
void	ppexpr(Node*, Node*);
void	pperror(char*, ...);
Node*	ppsetpointer(Node*, void*, Metatable*);
Node*	pppointer(void *v, Metatable*);
Pointer* pppointernode(void *v, Metatable*);

Node*	ppdup(Node*);
Node*	ppsetnil(Node*);
Node*	ppsetstring(Node*, char*);
Node*	ppsetstringlen(Node*, char*, int);
Node*	ppstring(char*);
Node*	ppsetconst(Node*, vlong);
Node*	ppconst(vlong);

List*	pplist(int);