consider following code segment
def valid_row?(%{"acu" => acu}) when is_number(acu) do
acu_limit = Application.get_env(:beam_checker, :acu_limit)
acu > acu_limit
end
since elixir/erlang comparison operator is very broad, the above code will never throw any exception irrespective of what is the data type or value for acu and acu_limit. But the end result is totally unexpected in cases where wrong types are supplied. two actual error cases which happened (and took some time to discover due to no exception) :
1) acu_limit was not defined in config, hence acu_limit got value nil
2) acu_limit was defined as string value in config
possible options for discussion:
1) can we have Integer.compare and Float.compare functions. That way whenever numeric comparisons are needed, these dedicated functions can be used. (preferred)
2) strict comparison version of > and < operators (something along the lines of == and ===, but for comparison)
option not for discussion
1) make a private comparison function, which throws an error if input values are not numbers. this is what I currently did.
thanks
miwee