Re: Ada Readability, Book Reference

[asuvax!ennews!telesys!weyrich!orville@gatech.edu (Orville R. Weyrich)]

In article <9212281507.AA20416@ajpo.sei.cmu.edu> SAHARBAUGH@ROO.FIT.EDU writes:
>
>So I ask "Is Ada readable if you can express an indeterminate
>program using it?".
>
>sam harbaugh
>---

I am not sure whether there is a relationship between indeterminancy and
readability.

Suppose, for example, the indeterminancy arises because of a concession made
to the implementors by way of not completely defining the effect of certain
language constructs [i.e. "implementation-defined"]. Suppose then I were to
arbitrarily define these aspects [very arbitrarily -- I'm being a devil's
advocate here] to depend on the number of comments in the compilation unit.

I have eliminated the indeterminancy, but certainly have not enhanced the
readability.

Or suppose, for another example, the indeterminancy arises because of a 
race condition that is outside the scope of control of the compiler and
run-time system. The indeterminancy could perhaps be resolved by introducing
semophores or some similar construct, but that would further complicate the
program text.

In my opinion, one of the best measure of readability is how well 
the semantics of a fragment of code can be determined in isolation from 
the context of the entire program. Another measure of readability is what
I might call "stability" -- minor changes in the code should result in
minor changes in semantics, not major changes. In other words, if a
reader has a small misunderstanding of what he/she read, and that leads
to a small misunderstanding of what the code does, the code is stable.

Happy new year to all.


orville

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