Hi Laurent,

> # uLong compressBound (uLong sourceLen)
> # int compress2(Bytef *dest, uLongf *destLen, const Bytef *source,
> uLong sourceLen, int level)

I'm afraid I can give only a partial answer, as I don't understand the
exact requirements of these functions well enough.

However, here are some points:

The lines

   '(dest `(genCharBuff bufSize) . 0)  # *dest
   '(destLen (8 . N) . `bufSize)       # *destLen

are probably a problem. For one thing, using a read macro (with
backquote) here doesn't do what you expect, because 'bufSize' is not
bound yet when the function 'Zcompress2' is read.

You can check that with (pp 'Zcompress2):
   (native "libz.so"
      '(dest (NIL B) . 0)
      '(destLen (8 . N))

Also, the size and type specifier must be reversed in the cons pairs.
Correct would probably be

   (dest (<bufSize> B . <bufSize>))  # Return in 'dest', buffer size, return 
<bufSize> bytes


   (destLen (8 . N) (<bufSize> . 8))  # Pass buffer size as long, return a long

Then I would stay with some naming conventions, define 'Dest' and
'DestLen' as local variables, and get finally:

   (de Zcompress2 (InBuf Level)
      (let (InBufSize (size InBuf)  BufSize (ZcompressBound InBufSize))
         (use (Dest DestLen)
                  "libz.so"                        # lib file
                  "compress2"                      # function
                  'I                               # return value (error status)
                  (list 'Dest                      # *dest
                     (cons BufSize 'B BufSize) )
                  (list 'DestLen                   # *destLen
                     (8 . N)
                     (cons BufSize 8) )
                  InBuf                            # *source
                  InBufSize                        # sourceLen
                  Level )                          # level
               (head DestLen Dest) ) ) ) )

   - For system libraries, you don't need to pass the full path. Thus,
     instead of (native "/usr/lib/libz.so" ..) you can simply write
     (native "libz.so" ..)

   - I don't know what 'compress2' does with multibyte UTF-8 chars, but
     in any case it is better to use (size inBuf) instead of (length

- Alex
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