lua/lparser.h

/*
** $Id: lparser.h,v 1.8 2000/03/03 14:58:26 roberto Exp roberto $
** LL(1) Parser and code generator for Lua
** See Copyright Notice in lua.h
*/

#ifndef lparser_h
#define lparser_h

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


/* maximum number of local variables */
#ifndef MAXLOCALS
#define MAXLOCALS 200		/* arbitrary limit (<=MAXARG_B) */
#endif


/* maximum number of upvalues */
#ifndef MAXUPVALUES
#define MAXUPVALUES 32		/* arbitrary limit (<=MAXARG_B) */
#endif


/* maximum number of variables in the left side of an assignment */
#ifndef MAXVARSLH
#define MAXVARSLH 100		/* arbitrary limit (<=MAXARG_B) */
#endif


/* maximum number of parameters in a function */
#ifndef MAXPARAMS
#define MAXPARAMS 100		/* arbitrary limit (<=MAXLOCALS) */
#endif


/* maximum stack size in a function */
#ifndef MAXSTACK
#define MAXSTACK 256		/* arbitrary limit (<=MAXARG_A) */
#endif



/*
** Expression descriptor
*/

#define NOJUMPS		0

typedef enum {
  VGLOBAL,  /* info is constant index of global name */
  VLOCAL,   /* info is stack index */
  VINDEXED, /* info is info of the index expression */
  VEXP      /* info is NOJUMPS if exp has no internal jumps */
} expkind;

typedef struct expdesc {
  expkind k;
  int info;
} expdesc;


/*
** Expression List descriptor:
** tells number of expressions in the list,
** and gives the `info' of last expression.
*/
typedef struct listdesc {
  int n;
  int info;  /* 0 if last expression has no internal jumps */
} listdesc;


/* state needed to generate code for a given function */
typedef struct FuncState {
  TProtoFunc *f;  /* current function header */
  struct FuncState *prev;  /* enclosing function */
  int pc;  /* next position to code */
  int stacksize;  /* number of values on activation register */
  int nlocalvar;  /* number of active local variables */
  int nupvalues;  /* number of upvalues */
  int nvars;  /* number of entries in f->locvars (-1 if no debug information) */
  int lastsetline;  /* line where last SETLINE was issued */
  expdesc upvalues[MAXUPVALUES];  /* upvalues */
  TaggedString *localvar[MAXLOCALS];  /* store local variable names */
} FuncState;


TProtoFunc *luaY_parser (lua_State *L, ZIO *z);


#endif