Re: Options for signed 64bit ints

[Andrew Starks <andrew.starks@...>]

On Thu, Aug 1, 2013 at 8:56 PM, Luiz Henrique de Figueiredo
<lhf@tecgraf.puc-rio.br> wrote:
> /*
> * lint64.c
> * int64 nummbers for Lua
> * Luiz Henrique de Figueiredo <lhf@tecgraf.puc-rio.br>
> * Thu Aug  1 22:56:17 BRT 2013
> * This code is hereby placed in the public domain.
> */
>
> #include <stdlib.h>
>
> #define Int             long long
>
> #include "lua.h"
> #include "lauxlib.h"
>
> #define MYNAME          "int64"
> #define MYTYPE          MYNAME
> #define MYVERSION       MYTYPE " library for " LUA_VERSION " / Aug 2013"
>
> #define Z(i)            Pget(L,i)
> #define O(i)            luaL_optnumber(L,i,0)
>
> #define add(z,w)        ((z)+(w))
> #define sub(z,w)        ((z)-(w))
> #define mul(z,w)        ((z)*(w))
> #define div(z,w)        ((z)/(w))
> #define neg(z)          (-(z))
> #define new(z)          (z)
>
> static Int Pget(lua_State *L, int i)
> {
>  switch (lua_type(L,i))
>  {
>   case LUA_TNUMBER:
>    return luaL_checkint(L,i);
>   case LUA_TSTRING:
>    return atoll(luaL_checkstring(L,i));
>   default:
>    return *((Int*)luaL_checkudata(L,i,MYTYPE));
>  }
> }
>
> static int pushInt(lua_State *L, Int z)
> {
>  Int *p=lua_newuserdata(L,sizeof(Int));
>  *p=z;
>  luaL_setmetatable(L,MYTYPE);
>  return 1;
> }
>
> static int Leq(lua_State *L)                    /** __eq(z,w) */
> {
>  lua_pushboolean(L,Z(1)==Z(2));
>  return 1;
> }
>
> static int Llt(lua_State *L)                    /** __lt(z,w) */
> {
>  lua_pushboolean(L,Z(1)<Z(2));
>  return 1;
> }
>
> static int Ltostring(lua_State *L)              /** __tostring(z) */
> {
>  char b[100];
>  sprintf(b,"%lld",Z(1));
>  lua_pushstring(L,b);
>  return 1;
> }
>
> #define A(f,e)  static int L##f(lua_State *L) { return pushInt(L,e); }
> #define B(f)    A(f,f(Z(1),Z(2)))
> #define F(f)    A(f,f(Z(1)))
>
> B(add)                  /** __add(z,w) */
> B(div)                  /** __div(z,w) */
> B(mul)                  /** __mul(z,w) */
> B(sub)                  /** __sub(z,w) */
> F(neg)                  /** __unm(z) */
> F(new)                  /** new(z) */
>
> static const luaL_Reg R[] =
> {
>         { "__add",      Ladd    },
>         { "__div",      Ldiv    },
>         { "__eq",       Leq     },
>         { "__lt",       Llt     },
>         { "__mul",      Lmul    },
>         { "__sub",      Lsub    },
>         { "__unm",      Lneg    },
>         { "__tostring", Ltostring},
>         { "new",        Lnew    },
>         { NULL,         NULL    }
> };
>
> LUALIB_API int luaopen_int64(lua_State *L)
> {
>  if (sizeof(Int)!=8) luaL_error(L,"Int has %d bytes but expected 8",sizeof(Int));
>  luaL_newmetatable(L,MYTYPE);
>  luaL_setfuncs(L,R,0);
>  lua_pushliteral(L,"version");                  /** version */
>  lua_pushliteral(L,MYVERSION);
>  lua_settable(L,-3);
>  lua_pushliteral(L,"__index");
>  lua_pushvalue(L,-2);
>  lua_settable(L,-3);
>  return 1;
> }

Luiz,

Your generosity is appreciated, both for what the code does and as an
example of "how it is done."

I will use it well.

I assume there is no objection to posting it on github?

- Andrew