Ada Configuration API for Unix and Windows

Ada Configuration API for Unix and Windows

[Ulrich Eckhardt]

Hi,

as promised some time ago, i have finished my platform independent API
for accessing configuration informations (Copyright GPL).
More infos on http://www.uli-eckhardt.de/ada_registry/

Comments and suggestion are welcome.

Uli
-- 
Ulrich Eckhardt
http://www.uli-eckhardt.de

Re: Ada Configuration API for Unix and Windows

[Stephen Leake]

Ulrich Eckhardt <uli.e@gmx.de> writes:

> Hi,
> 
> as promised some time ago, i have finished my platform independent API
> for accessing configuration informations (Copyright GPL).

just a nit; "GPL" is a _license_, not a _copyright_. The copyright to
this code is owned by you; you choose to release it under the GPL
license. Sometimes, this matters :). Ah, you do have this right on the
web page.

> More infos on http://www.uli-eckhardt.de/ada_registry/

In an example, you have:

  Put(reg,To_Key("A_Key"),"A Value"); -- A Key in the default section
  
Why is the conversion To_Key necessary? Surely it could be done by Put?

-- 
-- Stephe

Re: Ada Configuration API for Unix and Windows

[Martin Dowie]

"Stephen Leake" <Stephen.A.Leake@nasa.gov> wrote in message
news:uadjmvl9m.fsf@nasa.gov...
> In an example, you have:
>
>   Put(reg,To_Key("A_Key"),"A Value"); -- A Key in the default section
>
> Why is the conversion To_Key necessary? Surely it could be done by Put?

I'm guessing but it could be to ensure the user has a second look and
doesn't
get their 'keys' and 'values' the wrong way round (as both would be
strings)...

...or it could just be an oversight! :-)

Re: Ada Configuration API for Unix and Windows

[Stephen Leake]

"Martin Dowie" <martin.dowie@no.spam.btopenworld.com> writes:

> "Stephen Leake" <Stephen.A.Leake@nasa.gov> wrote in message
> news:uadjmvl9m.fsf@nasa.gov...
> > In an example, you have:
> >
> >   Put(reg,To_Key("A_Key"),"A Value"); -- A Key in the default section
> >
> > Why is the conversion To_Key necessary? Surely it could be done by Put?
> 
> I'm guessing but it could be to ensure the user has a second look and
> doesn't
> get their 'keys' and 'values' the wrong way round (as both would be
> strings)...

Hmph. That's what named association is for:

Put (reg, Key => "A_Key", Value => "A Value");

-- 
-- Stephe

Re: Ada Configuration API for Unix and Windows

[Martin Dowie]

Stephen Leake <Stephen.A.Leake@nasa.gov> wrote in message news:<usmxeu2vd.fsf@nasa.gov>...
> > I'm guessing but it could be to ensure the user has a second look and
> > doesn't
> > get their 'keys' and 'values' the wrong way round (as both would be
> > strings)...
> 
> Hmph. That's what named association is for:
> 
> Put (reg, Key => "A_Key", Value => "A Value");

Yes, but I still find some engineers who don't use it.
Presumably as it it more typing for their fingers!
Never mind the how useful the feature is. :-(

Perhaps this wasn't the reason, I was just guessing
after all.

Re: Ada Configuration API for Unix and Windows

[Ulrich Eckhardt]

Stephen Leake wrote:
> Ulrich Eckhardt <uli.e@gmx.de> writes:

> just a nit; "GPL" is a _license_, not a _copyright_. The copyright to

Hi,

thanks, i will have a look on this.

> In an example, you have:
> 
>   Put(reg,To_Key("A_Key"),"A Value"); -- A Key in the default section
>   
> Why is the conversion To_Key necessary? Surely it could be done by Put?

I have decided to introduce special types for sections and values,
so that the user can not accidentialy permute sections and keys or
other unbounded strings, specialy when variables are used (and not
simple string literals like in the example).

Uli
-- 
Ulrich Eckhardt
http://www.uli-eckhardt.de

Re: Ada Configuration API for Unix and Windows

[Stephen Leake]

Ulrich Eckhardt <uli.e@gmx.de> writes:

> Stephen Leake wrote:
> > In an example, you have:
> >   Put(reg,To_Key("A_Key"),"A Value"); -- A Key in the default section
> >   Why is the conversion To_Key necessary? Surely it could be done by
> > Put?
> 
> I have decided to introduce special types for sections and values,
> so that the user can not accidentialy permute sections and keys or
> other unbounded strings, specialy when variables are used (and not
> simple string literals like in the example).

That seems to make sense at first, but just gets in the way in the
long run. A string is a string. Named association is a better
solution. 

-- 
-- Stephe

Re: Ada Configuration API for Unix and Windows

[Ulrich Eckhardt]

Stephen Leake wrote:
> Ulrich Eckhardt <uli.e@gmx.de> writes:
>>I have decided to introduce special types for sections and values,
>>so that the user can not accidentialy permute sections and keys or
>>other unbounded strings, specialy when variables are used (and not
>>simple string literals like in the example).
> 
> That seems to make sense at first, but just gets in the way in the
> long run. A string is a string. Named association is a better
> solution. 

You can use named associations, but you don't have to use them.
Also they do not prevent to use accidentialy a wrong variable.

Assume you have some sort of ugly code like

ak : Constant r_key := To_Key("A_Key");
as : Constant r_section := To_Section("A_Section");
..

Set_Section(reg,ak);
Put(reg,as,"A Value");

Named association may not help in this case, since the user
has accidentialy permutet the use of this variables. However,
since i have extra types, the compiler will find this error.

Of course, the above example is constructed, but sometimes you
may have some complicated data structures lists etc ...

Uli
-- 
Ulrich Eckhardt
http://www.uli-eckhardt.de

Re: Ada Configuration API for Unix and Windows

[Victor Porton]

In article <903lsa-l91.ln@uli.uli-eckhardt.de>,
	Ulrich Eckhardt <uli.e@gmx.de> writes:
> Stephen Leake wrote:
>> Ulrich Eckhardt <uli.e@gmx.de> writes:

> ak : Constant r_key := To_Key("A_Key");
> as : Constant r_section := To_Section("A_Section");

Well, better Key_Type("A_Key") and Section_Type("A_Section"),
it is less confusing and error-prone (no overloaded functions)
as is straight usage of type conversions, not anti-intuitive
(as shown by previous discussion) functions.

Re: Ada Configuration API for Unix and Windows

[Grein, Christoph]

> > >   Put(reg,To_Key("A_Key"),"A Value"); -- A Key in the default section
> > >   Why is the conversion To_Key necessary? Surely it could be done by
> > > Put?
> > 
> > I have decided to introduce special types for sections and values,
> > so that the user can not accidentialy permute sections and keys or
> > other unbounded strings, specialy when variables are used (and not
> > simple string literals like in the example).
> 
> That seems to make sense at first, but just gets in the way in the
> long run. A string is a string. Named association is a better
> solution. 

declare
  -- type T is new String;  or alternatively
  type T is array (Positive range <>) of Character;
  procedure P (L: T; R: String) is
  begin
    null;
  end P;
begin
  P ("AAA", "BBB");      -- legal
  P (T'("AAA"), "BBB");  -- legal
  P (T("AAA"), "BBB");   -- illegal (type of "AAA" can not be determined)
end;

So again: Why is the conversion necessary?