[Chicken-users] Is there interest in a new egg (fast-io)?

[Jeronimo Pellegrini]

Hello,

I've been working on some unsafe fast I/O procedures for my own use,
and I thought I'd make them an extension, if more people would
like to use them.

The "fast-io" extension would have these procedures:

Implemented and tested:
- write-fixnum, read-fixnum
- write-flonum, read-flonum
- write-one-char, read-one-char (I don't know if the names
  are OK; I didn't want them to conflict with R5RS procedures)

Implemented, not tested:
- write-complex, read-complex

Planned but not yet implemented:
- write-string
- read-string-n
- read-string-until (reads until a delimiter is found)
- read-string-between (ignores characters until left
  delimiter, then reads until right delimiter)

All of these are implemented using (as little as possible)
foreign-lambda* with some inline calls to fprintf, fscanf,
and fgetc.
The only kind of error checked for is the return from the
C functions (and if, for example, fscanf fails to read,
then a (configurable) scheme error procedure is called).

The two last string-reading procedures will be triple-checked
for security. :-)

Why:
For everyday use, I really think this isn't necessary. But if
you need (as I think I'll need) to read and write very large amounts
of numbers from/to files, several times. Then this becomes useful.

If you *know* that your file only has fixnums or flonums (written
by your program), then you can use these procedures -- so there's
no need to make the program go checking if it looks like an exact or
inexact number, or as a string, or whatever. Just tell it to "read
an integer number!")

If there is interest, it's already packaged as an egg (installed on
my machine). 

The speedup I got is on the following table:

                scheme    fast-io   speedup
-------------------------------------------
write fixnum    14.602      5.303    2.7535
read  fixnum    58.208     11.706    4.9725

write flonum    37.003     21.647    1.7094
read  flonum   100.367     15.626    6.4231
-------------------------------------------

These are for reading and writing values from/to large files.
I'll include the benchmarking code with the egg, as well as
tests.

Thanks,
J.