/*

** $Id: lparser.h,v 1.57.1.1 2007/12/27 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