niels_bom
Idiomatic: pattern matching with two function heads or boolean guard clause?
I just found myself writing this:
def foo([], _), do: []
def foo(_, 0), do: []
But then I thought I could also use a guard clause with a boolean OR, like so:
def foo(list, n) when list == [] or n == 0, do: []
Is either version more idiomatic?
Would it maybe depend on the amount of code in the function? (DRY and all)
Because pattern matching is so nice and in this case the function body is very small I’ll probably choose the first version.
Thanks!
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NobbZ
The first one, as it leaves more room for optimisation by the compiler. Also matching 0 in the function head is more strict than x == 0 since 0.0 == 0.
PS: sometimes, if from business perspective both cases are to treat the same and not only by accident, I tend to use a guard using ===, as it better communicates indent of treating this cases the same.
dimitarvp
I use both of these idioms – and others – quite often. My main heuristic is: “is the code readable?”
The only non-idiomatic Elixir in such cases would be a load of if-s. The rest is quite fine and the exact idiom should vary depending on your priorities and the situation.
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