(match) is not strict

[iacore]

(match [1] [] 1 0) is 1.

What currently works:

(match [1] ([& xs] (empty? xs)) 1 0)

[CosmicToast]

Yes, match is strict on types and then on values.
If you don't specify a value, match will simply match on the type.
However, match statements are ordered, so I recommend doing something along these lines:

(match [:some]
  [a b & rest] :two-or-more
  [a] :one # depending on your use case just [head & tail] is sufficient, e.g for recursive algorithms
  [] :empty)

[iacore]

this is not pattern matching that I expected 😆

[sogaiu]

You are not alone :)

FWIW, there is some coverage of some unexpectedness of match in the Control FLow chapter of the "Janet for Mortals" book.

Janet’s implementation of pattern matching happens to have a couple rough edges that you’ll need to be aware of when you’re using match.

If interested, search for "rough edges" at the page linked to.

[ianthehenry]

I wrote https://github.com/ianthehenry/pat because of this and the lack of alternative cases in the default match. It's close to a drop-in replacement, but with exact-by-default indexed patterns.