From: "Hal E. Fulton" <hal9000@...>
Date: 2002-09-11T06:34:16+09:00
Subject: Re: Equivalent of pascal's keypressed  ?

----- Original Message -----
From: "Ryan King" <rking@panoptic.com>
To: "ruby-talk ML" <ruby-talk@ruby-lang.org>
Sent: Tuesday, September 10, 2002 4:14 PM
Subject: Re: Equivalent of pascal's keypressed ?


> On 2002.09.11, Kero van Gelder <kero@chello.nl> wrote:
> > > If we implemented a cross-platform "keypressed", might there be
> > > any chance of it getting into the builtin library?
> > >
> > > A frequent beginner C/C++ FAQ is the one above.  It seems like a
> > > high-level language such as ruby should be able to give a good
> > > solution to it, rather than a lengthy answer involving Win32 API
> > > or Termios witchery.
> >
> > select[[$stdin], nil, nil]
> >
> > if key_pressed() does not allow mixing with select(), it lost its
efficiency.
> >
> > disclaimer: unlikely to work on Win*
>
> ^ There's the problem.  Surely something could be worked out for
> Windows, too.  However, expecting individual programmers to
> reinvent those wheels is a violation of the DRY principle.
>
> I think it would be handy to have key_pressed, or preferably
> "getch", as a part of the standard library.
>
> I could be wrong, though.

I think I'm generally in favor of this kind of thing,
but I'd like it to be isolated in some kind of "OS-
sensitive" library.

It's likely to be implemented differently on *every*
different OS, not just Win and *nix.

I'm not sure how much of that it's appropriate to reveal
to the coder and how much to conceal.

The old fork() that worked under Cygwin is a case in point.
Should we have a fork() on Win32 that perhaps calls
CreateProcess? Or should we just not even pretend that
Win is anything like *nix? Many of the file operations
work transparently between the two. Where do you draw
the line?

Hal