Subject: Re: Reviews for lisp implementations
From: Erik Naggum <erik@naggum.no>
Date: 1999/04/18
Newsgroups: comp.lang.lisp
Message-ID: <3133417387581097@naggum.no>

* Vassil Nikolov <vnikolov@poboxes.com>
| Correct me if I am wrong, but the above (quoted) paragraph does not
| contradict a statement that using 15/15 for a printable character is
| inappropriate.  Or did I miss anything?

  yes.  10/0 and 15/15 are characters when the right-hand side of an 8-bit
  character set (GR) is filled with a 96-character set.  (the other 32 are
  control characters (C1).)  if you had filled it with a 94-character set,
  it would have been inappropriate to use 15/15 at all.

  the reason for this is that 10/0 and 15/15 are characters in their own
  right and must be coded with 8 bits, but if you use a shifting coding
  with only 7 bits and codes to swap between G0 and G1 (both now in GL)
  with the codes SO and SI, then it's important that 2/0 and 7/15 remain
  their usual semi-control characters even when G1 is invoked.

| I don't understand your point here.

  seems I was mistaken about the up/downcasing of I with/without dots.
  (shoot, gotta check and go back and fix those files for Emacs.)

| I wondered (as an academic exercise) what should CHAR-UPCASE and
| NSTRING-UPCASE do about LATIN SMALL LETTER Y WITH DIAERESIS (assuming
| STRING-UPCASE is allowed to return a longer string which isn't especially
| nice either).   Signal an error?  Or the implementation would state that
| the character sets it uses do not include this letter?  (Making
| CHAR-UPCASE return two values, like #\I and #\J in this case, appears
| more than perverse, though who knows.)

  I have come to think that people who use sick writing systems should pay
  for their own mistakes so they will have reason to fix them.  forcing
  everybody else to pay for them only causes software not to be available.
  e.g., the Spanish purportedly undid the silly sorting requirements of ll
  (treated as a separate "letter" between k and l, I think it was) due to
  the force of simplicity and logic of computers (or was it marketing :).
  a German spelling reform (which people seem to hate rather strongly) do
  away with the sharp s and spell it "ss" in lowercase, too.  the Norwegian
  and Danish sillitude of sorting "aa" as equivalent to "å" (a ring), and
  the hysterical requirement that German spelled out with "ue" instead of
  "ü" should be sorted as if it wasn't spelled out are examples of morons
  who got into standards bodies.  (now, the right way to do this is to
  store a sort key and a print string, but since people don't use tools
  easily extendible that way, forcing stupid people to do this causes a lot
  of grief and problems when they try to print the sort key or vice versa.)

  anyway, let's just ignore the issue and ask them to spell it out as ij,
  like the Dutch correctly do.  (the ÿ is Belgian, _from_ Dutch ij.)  (I'm
  not sure upcasing "ij" to "IJ" is all that great an idea, although it is
  obvious if you look at fonts designed in or for The Netherlands: they
  sport "ij" and "IJ" ligatures, just as fonts designed for Norway has a
  ligature for "fj" just like "fi", because of "fjord" and "fjell".)

  anyway.  8 bits would have been enough if we had been using floating
  diacritics and upcasing and downcasing would have needed to worry about
  A-Z, only.  ISO tried that, too, (ISO 6937) but computer people were not
  able to appreciate it, because they were thinking fonts, not character
  sets.  sigh.

  if there's reincarnation, I hope I won't remember any of this the next
  time around.

#:Erik
-- 
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