[erlang-patches] maps: pattern-match absent key?

[Björn-Egil Dahlberg]

Yes, with fail clauses.

f(#{ a := _ }) -> {a,present};
f(_) -> {a,absent}.



2014-02-18 20:55 GMT+01:00 Daniel Goertzen <daniel.goertzen@REDACTED>:

> Is there a way to pattern-match the absence of a key in a map?
>
> Dan.
>
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