ansaurus

Question

Should I be pattern matching every return value?

Answer 1

+11 A:

It's good programming style to crash as early as possible when something has gone wrong. Anything you execute after that will be done with the system in an unknown state.

Unless you intend to handle the error value and do something on it, you write your code for the successful case. As in the following little sad loop:

life() ->
  ok = work(),
  ok = rest(),
  life().

Christian 2009-12-24 01:09:38

Christian said it all...+1.

jldupont 2009-12-24 01:33:11

Yea, this is what I figured. The problem is one of the 3rd party APIs I'm using doesn't nicely return ok on success. After saving a document it returns the saved document itself. I get back SomeComplexDoc rather than {ok, SomeComplexDoc}.

Jeremy Raymond 2009-12-24 02:42:34

@Jeremy, You can just save the document, and then match on it in the next line. `Doc = my_api_call()`, `ok = is_valid_doc(Doc)`.

Zed 2009-12-24 08:54:33

Yes that's a good idea. I was doing something similar. SomeComplexDoc was either coming back as some big structure or an atom to indicate error. I could do something like `false = is_atom(Doc)` and this should fail if the save failed.

Jeremy Raymond 2009-12-24 19:24:14