Read this file if you want to call C code from Eiffel code.

The most common way to call C code from Eiffel is to use 
the `external' feature definition as described in ETL.
See also the SmallEiffel directory "lib_sow/external" to 
have some examples.
Here is the current list of SmallEiffel `external' specifications.

1- external "C" -
Simple call to a C funtion (or procedure). The external called 
routine do not get Current. A C prototype is automatically added
in generated heading C file.

2- external "CWC" -
Call With Current. The external called routine get Current as 
first argument. A C prototype is automatically added in generated
heading C file.

3- external "IC" -
Inlined C call. Same as external "C", but no prototype generated.

4- external "ICWC" -
Inlined CWC call. Same as external "CWC", but no prototype 
generated.

5- external "CSE" -
This external specification is reserved for SmallEiffel itself. Such
a feature is directly treated by `compile_to_c'. For example, infix "+"
of INTEGER is direcly mapped as C '+' for int C type.

6- Inlining C code -
Another way to call C code from Eiffel is to use "c_inline_c" or 
"c_inline_h" as defined in GENERAL. The argument of "c_inline_c"
(or "c_inline_h") must always be a manifest string which may 
contains the C code you want to put inlieu 
