How does the compiler check for exhaustive pattern matching?

[ivg]

No, but you can use when guards and as binds to implement some of them, e.g., F# pattern (x,y) & (_,"hello") could be encoded in OCaml as

• (x, "hello" as y) or as
• (x,y) when y = "hello".

See also,

Musings on extended pattern-matching syntaxes

Hello Discourse, I thought it might be amusing to share two ideas for extending OCaml’s pattern-matching syntax. (I don’t plan to implement them for now because technically it would be difficult.) with-patterns using and Agda has with abstractions, which allow to start, in the middle of a pattern-matching, to further match on the value of an expression: filter_map : {A B : Set} → (A → Maybe B) → List A → List B filter_map f [] = [] filter f (x ∷ xs) with f x filter f (x ∷ xs) | Some y =…