/*
** $Id: lparser.h,v 1.57.1.1 2007年12月27日 13:02:25 roberto Exp $
** Lua Parser
** See Copyright Notice in lua.h
*/

#ifndef lparser_h
#define lparser_h

#include "llimits.h"
#include "lobject.h"
#include "lzio.h"


/*
** Expression descriptor
*/

typedef enum {
 VVOID,	/* no value */
 VNIL,
 VTRUE,
 VFALSE,
 VK,		/* info = index of constant in `k' */
 VKNUM,	/* nval = numerical value */
 VLOCAL,	/* info = local register */
 VUPVAL, /* info = index of upvalue in `upvalues' */
 VGLOBAL,	/* info = index of table; aux = index of global name in `k' */
 VINDEXED,	/* info = table register; aux = index register (or `k') */
 VJMP,		/* info = instruction pc */
 VRELOCABLE,	/* info = instruction pc */
 VNONRELOC,	/* info = result register */
 VCALL,	/* info = instruction pc */
 VVARARG	/* info = instruction pc */
} expkind;

typedef struct expdesc {
 expkind k;
 union {
 struct { int info, aux; } s;
 lua_Number nval;
 } u;
 int t; /* patch list of `exit when true' */
 int f; /* patch list of `exit when false' */
} expdesc;


typedef struct upvaldesc {
 lu_byte k;
 lu_byte info;
} upvaldesc;


struct BlockCnt; /* defined in lparser.c */


/* state needed to generate code for a given function */
typedef struct FuncState {
 Proto *f; /* current function header */
 Table *h; /* table to find (and reuse) elements in `k' */
 struct FuncState *prev; /* enclosing function */
 struct LexState *ls; /* lexical state */
 struct lua_State *L; /* copy of the Lua state */
 struct BlockCnt *bl; /* chain of current blocks */
 int pc; /* next position to code (equivalent to `ncode') */
 int lasttarget; /* `pc' of last `jump target' */
 int jpc; /* list of pending jumps to `pc' */
 int freereg; /* first free register */
 int nk; /* number of elements in `k' */
 int np; /* number of elements in `p' */
 short nlocvars; /* number of elements in `locvars' */
 lu_byte nactvar; /* number of active local variables */
 upvaldesc upvalues[LUAI_MAXUPVALUES]; /* upvalues */
 unsigned short actvar[LUAI_MAXVARS]; /* declared-variable stack */
} FuncState;


LUAI_FUNC Proto *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
 const char *name);


#endif