Re: More thoughts on Lua 5.2

[Asko Kauppi <askok@...>]

The LNUM patch is useful for this as well.  It allows one to easily  
(with one to two -D flags) set Lua to use any combo of:

  LNUM_DOUBLE (default)         double precision FP (52 bit mantissa)
  LNUM_FLOAT                    single precision FP (23 bit mantissa)
  LNUM_LDOUBLE                  extra precision FP (80+ bit mantissa,  
varies)

  LNUM_INT32                    -2^31..2^31-1 integer optimized
  LNUM_INT64                    -2^63..2^63-1 integer optimized
  (none)                        		all numbers stored as FP

  LNUM_COMPLEX                  Complex (a+bi) number mode, scalars  
may be integer optimized

You'd use -DLNUM_INT64 to get 64-bit integer resolution. That's all.  
The patched Lua remains completely compatible to modules etc. -  
lua_Integer does become 64 bits wide. Numbers are stored as either 64- 
bit ints or doubles internally, but to your Lua code and C API it  
wouldn't be known.

-asko


Al Pfalzgraf kirjoitti 22.2.2008 kello 16:45:

> In recent work it would have been helpful if the Lua number  
> accomodated a 64 bit integer.
>
> Would a change of LUA_INTEGER to fpos_t be unacceptable?
>
>
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