Re: Alternatives to C: ObjectPascal, Eiffel, Ada or Modula-3?

[Ben Bacarisse <ben.usenet@bsb.me.uk>]

tm <thomas.mertes@gmx.at> writes:

> On 20 Jul., 11:57, Jean-Pierre Rosen <ro...@adalog.fr> wrote:
>> Andrea Taverna a écrit :
>> [...]>     - Ada is best suited for large teams and/or critical software, thus
>> > it may be overkill for my work, OTH it could have anything I might
>> > happen to need.
>> > What holds me from jumping onto Ada is the potential complexity
>>
>> As a long time teacher of Ada, let me elaborate on this particular issue.
>>
>> 1) More than complex, Ada is feature-rich, with some properties that do
>> not exist in most other languages (user defined elementary types,
>> discriminants, stack-allocated dynamic structures ...). Of course,
>> you'll have to learn about these features - if you want to use them.
>>
>> 2) Ada is extremely consistent. You'll have to learn the basic
>> principles, but once you've got them, you'll discover that all the
>> features follow the same logic. Therefore, the first step might be
>> higher than for other languages, but then everything appears logical and
>> easy to grasp.
>>
>> 3) Ada is simple to use, because difficulty of implementation has never
>> been an excuse for forbidding something that the user would expect to
>> work. However, that makes the language complex to compile, and part of
>> the alledged complexity of Ada refers to complexity of implementation,
>
> That is exactly the area where Ada left the path of Pascal. Pascal
> was designed to be easy to implement. Nicklaus Wirth had good
> reasons to keep the implementation simple. He once said (IIRC):
>
>   What can be parsed easily by a compiler can also be
>   parsed easily by a human and this can be an asset.

That is a fine notion.

> He probably did not use exactly this words, but they hopefully
> describe his intentions.
>
> Many languages try to make the job of writing a program easier
> and at the same time make the job of reading programs is
> harder. All this wonderful "do what I mean" concepts used by
> many languages fail in some cases.

Does Ada have any of these though?  I don't know the language well,
but I have never heard that accusation levelled at it (yes, I know you
are not doing so, but it was Ada that prompted your thoughts on this).

> IMHO complex compilation processes are an indication
> of hard-to-understand concepts or hard-to-read constructs.
> As such a complex compilation process only seemingly
> (and not really) makes programming easier.

I don't agree with that at all.  There must be a germ of truth in it
(a hard to implement notion must be somewhat harder to understand than
an easy to implement one) but presumably you are arguing for the
reverse: that keeping the implementation simple ultimately helps the
programmer.

I'd cite higher-order functions and rendezvous as counter examples.
There are easier to implement alternatives to both but neither is
hard to read not particularly hard to understand.  Even if we grant
that they are hard to understand, the benefit to programmers is
significant.  In my view, certainly worth the effort needed to
understand them.

-- 
Ben.