text: /*
  ** $Id: lparser.h,v 1.70 2012/05/08 13:53:33 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 */
    VNONRELOC,	/* info = result register */
    VLOCAL,	/* info = local register */
    VUPVAL,       /* info = index of upvalue in 'upvalues' */
    VINDEXED,	/* t = table register/upvalue; idx = index R/K */
    VJMP,		/* info = instruction pc */
    VRELOCABLE,	/* info = instruction pc */
    VCALL,	/* info = instruction pc */
    VVARARG	/* info = instruction pc */
  } expkind;
  
  
  #define vkisvar(k)	(VLOCAL <= (k) && (k) <= VINDEXED)
  #define vkisinreg(k)	((k) == VNONRELOC || (k) == VLOCAL)
  
  typedef struct expdesc {
    expkind k;
    union {
      struct {  /* for indexed variables (VINDEXED) */
        short idx;  /* index (R/K) */
        lu_byte t;  /* table (register or upvalue) */
        lu_byte vt;  /* whether 't' is register (VLOCAL) or upvalue (VUPVAL) */
      } ind;
      int info;  /* for generic use */
      lua_Number nval;  /* for VKNUM */
    } u;
    int t;  /* patch list of `exit when true' */
    int f;  /* patch list of `exit when false' */
  } expdesc;
  
  
  /* description of active local variable */
  typedef struct Vardesc {
    short idx;  /* variable index in stack */
  } Vardesc;
  
  
  /* description of pending goto statements and label statements */
  typedef struct Labeldesc {
    TString *name;  /* label identifier */
    int pc;  /* position in code */
    int line;  /* line where it appeared */
    lu_byte nactvar;  /* local level where it appears in current block */
  } Labeldesc;
  
  
  /* list of labels or gotos */
  typedef struct Labellist {
    Labeldesc *arr;  /* array */
    int n;  /* number of entries in use */
    int size;  /* array size */
  } Labellist;
  
  
  /* dynamic structures used by the parser */
  typedef struct Dyndata {
    struct {  /* list of active local variables */
      Vardesc *arr;
      int n;
      int size;
    } actvar;
    Labellist gt;  /* list of pending gotos */
    Labellist label;   /* list of active labels */
  } Dyndata;
  
  
  /* control of blocks */
  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 BlockCnt *bl;  /* chain of current blocks */
    int pc;  /* next position to code (equivalent to `ncode') */
    int lasttarget;   /* 'label' of last 'jump label' */
    int jpc;  /* list of pending jumps to `pc' */
    int nk;  /* number of elements in `k' */
    int np;  /* number of elements in `p' */
    int firstlocal;  /* index of first local var (in Dyndata array) */
    short nlocvars;  /* number of elements in 'f->locvars' */
    lu_byte nactvar;  /* number of active local variables */
    lu_byte nups;  /* number of upvalues */
    lu_byte freereg;  /* first free register */
  } FuncState;
  
  
  LUAI_FUNC Closure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff,
                                  Dyndata *dyd, const char *name, int firstchar);
  
  
  #endif
  