new code: character special names

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1


happy new year!

i've spent some time of my holidays writing a little bit of code for
pika. more concretely (and following tom's suggestion), i've extended
the special character names handled by read and write: all usual names
(newline, return, page, etc.) plus standard ASCII names are included
(in fact, the same set as systas').

i've also spent sometime with tla 1.2 and i've created a new _signed_[1]
archive with the following coordinates:

[email protected]
  http://tao.uab.es/jao/archives/2004

the above-mentioned code corresponds to revision
scm--devo--0.1--patch-1.

some comments on the code:

- - i've tried to hide away all details of char representation and name
  handling inside reps/char-imp.c (for instance, avoiding explicit bit
  twiddling in lexer.c, and things like that.)

- - i've noticed that pointer arguments are seldom checked for
  non-nullness: i've used now and then invariant(arg != 0) in my new
  functions, but maybe not checking is a design issue?

- - i've also missed the (consistent) use of 'const' qualifiers for
  pointer parameters of functions (what the c++ people call
  const-correctness). from my previous experience, a rigorous use of
  'const' improves the code's consistency and 'self-documentedness'.
  i've already used it in my pika hacks, but of course it must be a
  shared policy to be of any use. if you think it's worth the effort,
  i volunteer to review the current pika source tree to make it
  'const-correct'. but, again, maybe i am missing some design issue...

- - tom, i think my changes are quite self-explanatory, but if you want
  me to explain them in more detail to save you time, just ask! :).
  also, please let me know if the archive change poses any problem
  (the old one is still alive, btw).

cheers,
jao

Footnotes: 
[1]  My public key is (i'm signing this message, too):

- -----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.2.3 (GNU/Linux)
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==
=FZwq
- -----END PGP PUBLIC KEY BLOCK-----


- -- 
Any sufficiently advanced technology is indistinguishable from magic.
- -Arthur C Clarke, science fiction writer (1917- )
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (GNU/Linux)
Comment: Processed by Mailcrypt 3.5.8 <http://mailcrypt.sourceforge.net/>

iD8DBQE/91tblX2PbVNDo+wRApv2AKCbCoiSUyULNSdEou44kFcNwIK2ygCdFL1D
XaHoHmbKTguC45629/VBo3Y=
=DEGb
-----END PGP SIGNATURE-----