core.typed for nested Vecs

Question

I am trying to define a type definition for this datastructure:

[[:id :int :null false :pk true :autoinc true]
[:fooname [:varchar 40] :null false]
[:age :int :null false]]

And then I have a filter function which removes every vector containing :id as the first element like this:

(defn filter-id-columns [l]
  (remove #(= :id (first %)) l))

But, no matter what I try I always get a type error like this:

Type Error (leiningen/code_generator.clj:23:19) Polymorphic function first could not be applied to arguments:
Polymorphic Variables:
x

Domains:
(t/HSequential [x t/Any *])
(t/Option (t/EmptySeqable x))
(t/NonEmptySeqable x)
(t/Option (clojure.lang.Seqable x))

Arguments:
t/Any

Ranges:
x :object {:path [(Nth 0)], :id 0}
nil
x
(t/Option x)

in: (first p1__27917#)
in: (first p1__27917#)

I understand that I am providing the wrong type for the input argument, however, I fail to find the right thing.

Any ideas on how to fix this?

Answer 1

Function parameters default to Any. You must expand your local function definition like this: (t/fn [x :- (U nil (Seqable Any))] ...).