Aliases for keys?

Question

The syntactic sugar for alternatives in replacement rules is clean:

{a|b|c-> 1, d->2}

Are there any analogous shorthands for keys in associations. I want to specify multiple equivalent keys in an association, like this:

<| Key[a|b|c]-> 1, Key[d]->2|>

The motivation is that sometimes the values in key-value pairs are large (and so you'd rather not flatten it out and add duplicate them for each key alias).

$ChordFormulas = <|"Major"|"Maj"->{0,4,7}, "m"|"Minor"|"Min" -> {0,3,7}, "9"|"79"->...|>

Related:

• A shortened association

Answer 1

It seems you have already done it with Alternative.

c = <|"Major" | "Maj" -> {0, 4, 7}, "Minor" | "Min" -> {0, 3, 7}|>;

You would just need KeySelect and MatchQ.

KeySelect[MatchQ[#]@"Major" &]@c
(* <|"Major" | "Maj" -> {0, 4, 7}|> *)

or with ReplaceAll.

KeySelect["Maj" /. # -> True &]@c
(* <|"Major" | "Maj" -> {0, 4, 7}|> *)