Re: Terminal Column Number (was: TEXT_IO anomality)

Re: Terminal Column Number (was: TEXT_IO anomality)

["Jonathan B. Owen"]

In my original posting I brought up the issue of two internal files
(STANDARD_INPUT and STANDARD_OUTPUT) accessing the same external file
(read terminal).

I agree that the implementation is in accordance to the LRM.  When
accessing STANDARD_INPUT, the STANDARD_OUTPUT internal file is not
affected in any way.  Still, I am left with the problem I mentioned
at first.  The COL of STANDARD_OUTPUT does not reflect the position
of the cursor.  The difficulty is that I have no way of setting
the COL without producing an extra, unwanted CR.  It is one thing
to maintain internal-file independence, and another not to enable
a higher level to do so...

As to a concrete example for relying on COL of STANDARD_OUTPUT,
after the user types a "LIST" command (and presses return) I make
a recursive call to a procedure for printing a certain tree structure,
each time indenting the COL by 4.  The procedure uses the current
value of COL for printing multiple lines at the specific indent level.
The first line after the user's input is printed incorrectly.

Maybe it would be sensible to enable access to the counters so that
one can implement external-file dependency above TEXT_IO.

                                             Jonathan Owen

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