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A comment on Elixir at Ramp. Parent comment

Re:Elixir at Ramp by davidw on Friday November 24, 2023 @03:10PM (#38407692)
> custom guards

I don't recall 100%, but I think this is a BEAM feature that exists because they don't want to run arbitrary code as part of guards that could have side effects, delays and so on. I don't remember the specifics.

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Re:Elixir at Ramp by el_oni on Friday November 24, 2023 @06:25PM (#38409518)
You can write custom guards out of any built in function that can already be used in a guard.

Like defguard is_list_or_even_int(val) do is_list(val) or (is_integer(val) and val % 2 ==0) end

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