Re: integer'image

[mfeldman@seas.gwu.edu (Michael Feldman)]

In article <1991Jan20.025451.29808@ucselx.sdsu.edu> hoysch@ucselx.sdsu.edu (      Hoysch) writes:
>
>	I think a big thing is being made out of something that is not very
>hard to do.  For example INTEGER'IMAGE(I)(2..INTEGER'IMAGE(I)'LAST) will
>do it or a very simple routine if this is too hard on the eyes.  That 
>space, as has been pointed out, is often nice to have to offset the '-'
>of negative numbers.
>
Well, that'll work if I is positive. Otherwise it'll delete the -. So in
any case a test is needed to ascertain the sign. I'd prefer for 'image to
give me what's there, not add extra stuff that I have to delete.

One purpose for the 'image and 'value attributes, it seems to me, is to aid
in _writing_ I/O packages in lieu of (or on top of) Text_IO. The extra
blank just adds an extra bit of aggravation. I'd be happier with it if it
incorporated a general "pad" parameter, but it doesn't.

Recall that the thing that started this thread was developing a terminal-
control package that could easily ship ASCII sequences to a terminal to do
cursor movement, etc. There is no doubt that what you wrote is correct, for
positive values. I was complaining about the arbitrary lack of uniformity
in attributes, and this was the latest. I claim it's much easier to _add_
a blank to get the symmetry between positive and negative numbers than to
_delete_ the blank as you did. Ada9x is looking into the whole problem of
"edit-directed output", which will, if they really do it well, solve a lot
of these problems in a much more general way. Meanwhile, I don't like the
asymmetry between integer PUT and integer'image; in the former I can control
the width precisely because they thought to give me a parameter; in the latter
I cannot, and they decided to stick me with a gratuitous blank. I don't
think gratuitous padding is very user-friendly. The early subset compilers,
by the way, didn't add the blank - it got stuck in there somewhere between
the '80 and '83 versions of the standard, and I think they blew it.

Mike