Re: Separate Compilation in Programming Languages

[Niklas Holsti <niklas.holsti@tidorum.invalid>]

adaworks@sbcglobal.net wrote:
> "Niklas Holsti" <niklas.holsti@tidorum.invalid> wrote in message 
> news:47bf11df$0$14990$4f793bc4@news.tdc.fi...
> 
>>adaworks@sbcglobal.net wrote:
>>
>>
>>>Do you still use the "is separate" feature in a package body?
>>
>>I never use it. My subprograms are rarely long enough to make it useful (given 
>>that there is no compilation-speed advantage under GNAT), and I seldom use 
>>nested packages.
>>
> 
> Thanks.  The issue is not compilation speed, nor even size of the
> source code.   Rather, the real benefit of Ada's separate compilation
> model is the management of dependencies. 

I understand this point -- in theory. In practice, although I do 
worry about dependencies in general, I haven't seen cases where "is 
separate" would have been very useful, in my opinion.

True, often only some parts (subprograms) of a large package body 
depend on some given other package, and other parts do not, but it 
is rare for this selective dependency to apply to only one 
subprogram in the package.

If there are, say, three subprograms in package A that depend on 
package B, and I make these three subprograms "separate" to remove 
the "with B" clause from A, I now have three "with B" clauses in 
three different source-code files, instead of the one clause in the 
body of A.

The dependencies are more specific, good, but also there are more 
dependencies (and more source-code files), not so good. By YMMV.

-- 
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
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