[k13gomez]

walk-reduce, postwalk-reduce, and prewalk-reduce now accept any number of optional trailing secondary collections that are walked alongside the primary collection (paired by key for maps/records, by value/membership for sets, by index for vectors/lists/seqs) and passed as extra read-only arguments to the walk function, while remaining fully backward compatible with existing single-collection calls.

[k13gomez]

(w/postwalk-reduce
 (fn [match? a b]
   (if (and (fn? a)
            (not (fn? b)))
     [false ::did-not-match]
     [match? a]))
 true
 {:foo 1
  :bar {:baz odd?
        :quux {:quuux 3}}}
 {:foo 1
  :bar {:baz 2
        :quux {:quuux 3}}})
=>
[false
 {:foo 1
  :bar {:baz ::did-not-match
        :quux {:quuux 3}}}]