Re: Image attribute (yet again)

[Jere <jhb.chat@gmail.com>]

On Monday, April 27, 2020 at 8:33:31 AM UTC-4, J-P. Rosen wrote:
> Le 26/04/2020 à 19:33, Jere a écrit :
> > I'm not saying it can't be done.  I'm saying by the time I go through
> > all the processing needed, I might as well wrote my own function.  It
> > makes the existing operation mostly useless (unless I just want a 
> > temporary debug print that I don't care how it looks).  For example,
> > if I want to print to a 16x2 character LCD screen and I want to print
> > 0 padded 4 digit hex values with no "16#" prefix or "#" ending, then
> > I need to call Put with an 8 character string, search for the first
> > occurrence of '#' (it can be in multiple locations), then overwrite
> > a variable number of those characters with 0's (based on the location
> > of '#'), and then extract the 4 digits I actually need.  All doable 
> > (not saying it cannot be done), but at that point, I am better off 
> > just doing my own custom operation instead instead of even using the
> > Put operation.  
> Right. If you want you own format, write it. It will take you less time
> than writing this message. For the benefit of everybody, here it is:
> 
>
Yep, I do something similar to what you posted.  I was just
asking if the standard provided something more than what
Put provided as it wasn't quite adequate for the general case.  
It sounds like from your answer that I didn't miss
it (I was hoping!).  As I said earlier, for stuff like this 
I have generally rolled my own in Ada.  

> 
> > It feels like the Put operation wasn't designed 
> > with usability in mind.  Just the presence of the "16#" and "#" 
> > around the value makes using the operation more clunky than it 
> > should be.  If that had been left out or if the operation at least
> > allowed for padding the actual numeric value inside the result,
> > then it would have been much more usable.
> 
> Text_IO was designed for file operations, not so much for interactive
> IO. And there is an important feature of Text_IO which is rarely
> mentioned: If you use only the appropriate operations from Text_IO (no
> 'Image), and your program writes into a file, you can take the sequence
> of code that writes the file, replace every Put_* operation by the
> symetric Get_* operation, and you will read the file without error.
> 
> This feature requires that if you write a number in a certain base, then
> you need to recognize the base when reading. So it's not an error, but a
> design decision. Of course, like any design decision, you may agree with
> it or not.

Conceptionally that makes sense.  I do wish they had followed other
languages in at least providing some of the basic formatting options
for stuff like this.  Even if it was a different package (String_IO?).