Max Khesin <MKhesin <at> liquidnet.com> writes:
I am refactoring code that looks something like this:
if (op == LN::FILTER_IN || op == LN::FILTER_NOT_IN) { where += handle_set_operation(column, type, format, op, expr_set); } else if (op == LN::FILTER_RANGE) { where += handle_range_operation(column, type, format, op, expr_set); } else if (op == LN::FILTER_NULL || op == LN::FILTER_NOT_NULL) { where += handle_null_operation(column, op); } ...
I assume that you somewhere have a switch/case or multiple if/else if implementing dispatch on "where", before the above code is executed. If so, then this looks like the implementation of a state machine.
This would obviously be handled better with a map of some sort (has to map int to function). The problem here is that some functions have more arguments than others, precluding the possibility of uniform type for the function value of the map. I cannot just go and change the function sig to include dummy values ('cause it's a dumb idea). This situation made me think of boost.function/boost.bind, which allows to effectively shorten the function parameter list by binding some of the args.
It seems that would be possible, but I think (given that I'm right about the state machine nature of your code) there are better ways to implement this. You might want to have a look at boost::fsm: Docs only: http://boost-sandbox.sf.net/libs/fsm Code, examples and docs zipped: http://boost-sandbox.sf.net/fsm.zip Regards, Andreas