Just alias the command in your .bashrc? e.g. `alias n="nim compile --run n"`. I'm not sure what the issue is with longer commands because the benefits of writing in a strongly statically typed language definitely outweigh a few extra characters to type, which you don't even need to do with aliases.
For what it's worth, you need only type "nim r n". If "n.nim" is marked executable and begins with "#!/usr/bin/nim r" then you also need only type "n.nim".
