parsing optional arguments

Stream: lean4

[Scott Morrison]

If I have a n: Option (TSyntax `num), what is the idiomatic way to convert this to a Nat, by providing a default?

So far I have the rather unpleasant ((n.map (·.1.toNat)).getD 50).

[Gabriel Ebner]

You can simplify it to n.map (∙.getNat) |>.getD 50. But I don't think it gets better than that.