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From: =?utf-8?Q?Yannick_Duch=C3=AAne_=28Hibou57?=
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Newsgroups: comp.lang.ada
Subject: Re: best practice: error handling
Date: Sat, 11 Jun 2011 15:38:10 +0200
Organization: Ada @ Home
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Date: 2011-06-11T15:38:10+02:00
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Le Tue, 31 May 2011 19:13:16 +0200, Vinzent Hoefler  =

<0439279208b62c95f1880bf0f8776eeb@t-domaingrabbing.de> a =C3=A9crit:
> If you kind of expect the call to fail under normal conditions, a prop=
er
> out-Parameter (like "Success" ;) can be added.
>
> Keep in mind, that returning some error requires a function, and until=
  =

> now
> functions can't have "out"-parameters, so returning an "error code" is=
  =

> only
> possible for those subroutines which do not need to have  =

> "out"-parameters.
I strongly suspect this is precisely the reason why Ada 2012 will add ou=
t  =

parameters to function ;)
First, I though this was a silly idea, and later, from time to time, I  =

though this was indeed a good idea, at least to return status from  =

function, without the need to define wrapper types every where (at least=
,  =

while Ada do not have provision to return proper tuples like functional =
 =

languages do). Moreover, a function may still be conceptually Pure, even=
  =

with out parameters ;)

-- =

=E2=80=9CSyntactic sugar causes cancer of the semi-colons.=E2=80=9D  [Ep=
igrams on  =

Programming =E2=80=94 Alan J. =E2=80=94 P. Yale University]
=E2=80=9CStructured Programming supports the law of the excluded muddle.=
=E2=80=9D [Idem]
=E2=80=9Cc++; /* this makes c bigger but returns the old value */=E2=80=9D=
 [Anonymous]