Re: Get_Immediate has raised CONSTRAINT_ERROR : s-wchcnv.adb:207 explicit raise

[Georg Bauhaus <bauhaus@futureapps.invalid>]

On 18.02.15 21:36, Dmitry A. Kazakov wrote:
> On Wed, 18 Feb 2015 11:34:34 -0800 (PST), darek wrote:
>
>> So, are there any alternatives in Ada (GNAT) that should/may  be used for
>> this trivial task?
>
> It is not a trivial task, even in the days of teletypes, it was not. As for
> alternatives, Ada or not, use ncurses if you have to stay console-only, or
> a console terminal emulator, see below.
>
> Better make a proper GUI using GTK, Qt, WinGDI or gnoga. All have Ada
> interfaces, of course.

Ncurses, if at all necessary: in addition to the use case Darek has
mentioned, another use case  will not warrant a fancy GUI either;
there will be cursing when one needs to

(a) install a fully equipped graphical workstation(*) to manage
     a GNU/Linux based server system, say

(b) which drags in a load of software for just that fancy GUI,
     inflating the software repertoire to be managed; the "real"
      software does not need it at all.

Condescending comments will ensue, typically starting with "Just install …".
But they will only be heard as long as the speaker has not had
to manage a single task slightly different from what the GUI
designers have covered, or has had to do it at a computer that isn't
his own.

Many GUIs I have seen were incomplete, sluggish, and non-standard.
That's no surprise, I think, as it takes a fair amount of work to
make them handle everything well. In particular, when the OS offers
no direct support for such programs.  The task is difficult already when
using just text!

Maybe there is a correlation between administrative GUIs being
half-baked and graphical programming (not: GUI programming)
being not that popular?


Of course, all applies less to Windows™ XP style programming, as the
feel of text or scripting is a fairly recent addition to Windows™ NT
based OSs, and as users expect installers, say, to be as good as those
programs for controlling driver software. 8-)

__
(*) the screen may actually be virtual, without an option to
quickly alter its size, which adds another set of display problems,
e.g. dialogue windows being too large.