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

[unknown]

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

Dan.
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[unknown]

Yes, with fail clauses.

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

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