RE: A basic question on encoding Latin characters

From: Edward Cherlin (
Date: Sat Oct 02 1999 - 21:29:44 EDT

At 17:21 -0700 9/28/1999, Robert Brady wrote:
>On Tue, 28 Sep 1999, Murray Sargent wrote:
> > (The following may well have been mentioned earlier; I haven't followed the
> > whole thread). If you enter combining mark sequences using deadkeys, there
> > shouldn't be a problem. With deadkeys, nothing is displayed on
>the terminal
> > until the base character is typed and nothing is sent to the pattern-match
> > code. When the base character is typed, the corresponding fully
>composed or
> > partially composed character sequence is sent to the terminal and to the
> > pattern-match code. Deadkey input methods are usually part of the
> > underlying OS, but apps can also implement them fairly easily.
>That doesn't work. Consider a telnet connection. At the end of one TCP
>packet, the <a> is placed, but the <combining-ring-above> will not fit, so
>it has to go in the next packet.
>Maybe the second packet is delayed for a few seconds, due to network
>problems (why is not relevant).
>The app gets the <a> and then a few seconds later gets the
>If you can see a way round this (other than abandoning the terminal
>metaphor), the linux/utf-8 project would no doubt be happy to hear it. :)

Which protocols defined in some standard or by some vital piece of
software use prompts without terminators? You cited "Login:". What
else? Do any of them use character composition? How do they handle it?

Suppose, then, that we have a list of problematic applications and
standards documents, defined in each case for some specific selection
of character sets and transfer-encodings. Assume further that none
has this ambiguity using current character sets. Now describe the
precise process by which some designer paints the whole world into a
corner by using two minimally different prompts at the same point in
a server application, where the client is required to respond
differently to each prompt.

Extra Credit: Explain the designer's rationale for this design
choice, and why we have to help him/her do this.

You may use the APL FUNCTIONAL SYMBOL QUAD-COLON (U+2360) in your
answer, if you can think of a reason why it's relevant. :-)

Edward Cherlin, BA, Honors, Math and Philosophy, Yale 1967
"Those who get above zero, do very well. Those who get zero, do
well, but not so well. Those who get below zero, not do well."
Attributed to Yale math professor Shizuo Kakutani,
whose English was really much better than that.

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