Code Constructs

Unfortunately the current state of the Gromacs code is quite diverse, but for the future we try adhere to the UNIX way of doing things:

• Typically, a return value of 0 means success/OK, while non-zero error codes e.g. from /usr/include/errno.h indicate bad things.
• The exception to this is functions with obvious boolean names like is_alpha(), where we return 1 for true, 0 for false.
• Don't use the return value for other things! To prepare for threading, we need it to propagate error codes.
• Again, there are exceptions, like standard math functions x=gmx_invsqrt(y);
• Put arguments in the standard UNIX way, i.e. gmx_copy(to,from), or gmx_print(xlist, nx).

If in doubt, ask "what would Dennis Ritchie do?", or browse /usr/include for inspiration.