[erlang-questions] Must and May convention

Attila Rajmund Nohl <>
Wed Sep 27 11:25:05 CEST 2017

2017-09-27 11:08 GMT+02:00 Joe Armstrong <>:
> This turns out to be very convenient - I read many files
> in my programs, so it's nice to know that must_read_file
> will print a nice error message and terminate
> if I give it a bad filename.
> Note: I can get the program to crash by writing
>    {ok, B} = file:read_file(F)
> But I don't get a nice error message telling me the filename.
> Any takers?

My problem with all kinds of very common prefixes is that it breaks
function name autocompletion. Or at least makes it harder to use when
I have dozens/hundreds/thousands of function names starting with the
same 3-5 characters - either I have to type those 3-5 characters all
the time plus any more characters to find unique prefix for
autocompletion or have to autocomplete twice (one for the may/must
difference, one for the actual function name). Eclipse (for Java)
helpfully shows the method signature including return value and thrown
exceptions - I think this problem should be solved by the IDEs and not
by naming conventions.

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