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- Subject: Re: Rici tries to explain. Was Re: Arguments by reference?
- From: William Trenker <wtrenker@...>
- Date: Fri, 2 Sep 2005 14:35:27 -0400
On 9/1/05, Rici Lake <firstname.lastname@example.org> wrote:
> Let's trust the implementers to worry about
> the low-level stuff, and get it right. We can just think about the
> semantics, and how to write beautiful programs with that.
Agreeing wholeheartedly, may I pick a nit? Aren't there some
high-level semantics that can be derailed when the programmer has no
option but to work too close to the details? A simple example is
testing for an empty table.
The application of testing for an empty table is very common -- an
empty table conveys an empty set, or a null return value, or an
exhausted collection, etc. But in Lua a higher level thinker has to
resort to lower-level constructs to make this test. I can use the
next() function or, where applicable, I can use the table.getn()
function. But is the next() function "faster", or is getn() "better"?
Of course making that choice shouldn't concern me; those are
implementation details from the view of testing for table emptiness.
To get my head out of these low-level details I need a level of
interaction with the language that provides this decoupling. Wouldn't
something like table.isempty() do the trick of decoupling my
higher-level thinking from the implementation details? With such an
interface between higher-level semantics and lower-level details I can
safely assume that table.isempty() is the "best" implementation for
its purpose and I can confidently leave the details to the