Ray Dillinger  <bear@sonic.net> wrote:
+---------------
| Still, let's say I want something that's simple, but outside
| the standard, such as cursor control on a character-based
| interface (the "curses" library in UNIX).
| 
| This requires operating system calls, and therefore cannot
| be implemented using the functions given in the standard.
+---------------

The only operating system calls this requires are two "ioctl()" calls:
one to turn off/on echoing of input and one to switch between line-
oriented and character-oriented input ("cbreak") [and even that makes
sense only on Unix-like systems, and is *NOT* even portable across all 
of those (BSD-style vs. System-V-style, for example)]. Everything else
can be done just fine entirely within Common Lisp.

However, as Mathew Danish pointed out in a parallel reply, rather than
re-implement "curses" in Lisp, what most people do is just use some FFI
(such as UFFI or CMUCL's "alien") to call out to a C library version of
"curses"...


-Rob

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