Error on failed match?

[jtrakk]

Without a default match, the result is nothing.

For example, @match x begin 0 => 10; 2 => 20 end returns nothing. Usually when I forget a case, it's a bug in my code and I want an error rather than a nothing.

If I have nothing,

(1) I don't notice the problem, or
(2) if I do notice the problem, the error message about unexpected Nothing appears far away from the actual bug.

Whereas if I get an error, (1) I notice the problem and (2) the error shows me where the problem is.

Would it make sense to support the safer behavior by giving an error instead of nothing?

[Neal Gafter]

We now do that in version 2

julia> Pkg.status()
      Status `~/.julia/environments/v1.6/Project.toml`
  [7eb4fadd] Match v2.0.0

julia> @match 1 begin
          2 => 2
       end
ERROR: MatchFailure(1)
Stacktrace:
 [1] top-level scope
   @ REPL[20]:2