Re: Missing feature in 5.3: LUA_FLOAT_NONE for crippled C libraries

[Roberto Ierusalimschy <roberto@...>]

I may be missing something, but the following definitions in 'luaconf.h'
seem to do a good job of elliminating floats from Lua. A few caveats:

- Depending how you add these definitions to your luaconf.h, you will
have to undefine the original definition.

- I assume you removed the math lib (a one-line change in linit.c).

- There are some quirks; most of them I think were present also in
older versions of Lua converted to int:
  * exponentiation results in zero (we should provide our own
    implementation for integer exponentiation)
  * string.format for floats (%a, %f, %g, etc.) give weird results

-- Roberto

/* -----------------------------------------------------------------*/
#define LUA_NUMBER		LUA_INTEGER
#define LUAI_UACNUMBER		LUAI_UACINT
#define LUA_NUMBER_FRMLEN	LUA_INTEGER_FRMLEN
#define LUA_NUMBER_FMT		LUA_INTEGER_FMT

#define luai_numpow(L,a,b)	0  /* we should provide an implementation... */
#define luai_nummod(L,a,b,m)	((m) = luaV_mod(L, (a), (b)))
#define luai_numdiv(L,a,b)	luaV_div(L, a, b)
#define luai_numidiv(L,a,b)	luaV_div(L, a, b)

#define l_floor(x)	(x)

#define l_mathop(op)	X X X	/* ensure it is not being used */

#define LUA_COMPAT_FLOATSTRING

#define lua_str2number(s,p)	(*(p) = (char*)(s), 0)

#define l_hashfloat(n)	(n)

#define l_mathlim(x)	(LUAI_##x)
#define LUAI_MANT_DIG	63
#define LUAI_MAX_10_EXP	10	/* arbitrary */

#define lua_numbertointeger(n,p)	(*(p)=(n), 1)