Re: From extended Pascals to Ada 95 guide

[marcov@toad.stack.nl (Marco van de Voort)]

In article <39A991F3.A8D8BED7@easystreet.com>, Al Christians wrote:
>David Starner wrote:
>> 
>> Okay, why isn't Ada a "Wirth-style language", if Modula-3 is? They
>> share more in common with each other than either does with Wirth's
>> Pascal, for instance.
>> 
>
>The principal criterium is size of the language definition/reference 
>manual.  Modula-3's is under 60 pages, IIRC, much smaller than Ada's.
>And Wirth was some kind of advisor to the M3 design team. 

Why is that the principal criterium?

>M2 and M3 are both very nice languages if you want something simpler
>than Ada and don't need what they leave out.  But neither one shows
>much sign of life. 

That's true. This is the reason I started with Pascal again. Commercially
there are still two fairly decent M2 compilers (XDS and StonyBrook), but I
didn't want a commercial compiler.

>All three of these languages, M2, M3, and Ada, now support generics, 
>and that gives them a big advantage over Delphi for coding without doing 
>aribtrary conversions between data types.  

Could you elaborate on this?

>program must cast it to whatever type it really represents.  One big 
>reason Borland's Pascal became popular was because it let you go
>around Pascal's strict type checking, but that was years ago, 

BP was usable at a time that very strict principals (in either libraries,
typing etc) were simply to slow. IIRC Borland didn't only strip some typing, 
but a lot of other features that stood in the way of fast programs.
(e.g. interprocedural goto's?)

> and it's 
>regrettable to have to routinely write code that will be checked 
>for correctness at run time when there are less worrisome alternatives.

Of course in a standard Delphi program those stress tested VCL classes are
used mostly.

>I don't believe that Wirth's versions of M2 or Pascal allowed any way
>to go around the type system, and in M3, the modules that might do
>so must be marked as unsafe.  Ada does allow unchecked conversions.