Re: [ANN] Lua 5.2.0 (work1) now available
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- Subject: Re: [ANN] Lua 5.2.0 (work1) now available
- From: Drake Wilson <drake@...>
- Date: 2010年1月15日 00:37:25 -0600
Quoth Doug Currie <doug.currie@gmail.com>, on 2010年01月14日 22:54:12 -0500:
> ...unless we were Common Lisp programmers in another life. There,
> (ash x n), or bit.ashift(x, n), as it might be spelled in Lua, is
> defined simply as an integer x * 2^n.
[...]
> They are useful for do-it-yourself floating point: arithmetic on the
> exponents lead to signed shift adjustments of the mantissas.
Note that math.ldexp is already present, at least when Lua numbers are
doubles. Having ldexp be signed-shift-argument shift when numbers are
integers would be an interesting graceful degradation for the X * 2^N
meaning.
---> Drake Wilson