Clarify and maybe change unparse behavior

[tomconnors]

As posted on slack, data equal to the result of malli.core/parse cannot be unparsed.

(def int-or-string [:orn [:int :int] [:str :string]])

(malli.core/parse int-or-string 1) ;; -> [:int 1]

(= [:int 1] (malli.core/parse int-or-string 1)) ;; -> true

(malli.core/unparse int-or-string [:int 1]) ;=> :malli.core/invalid

(->> 1
     (malli.core/parse int-or-string)
     (malli.core/unparse int-or-string)) ;; => 1

I have some data in my schema's parsed format, which was not produced by parse, but which I would like to unparse. It appears that's not currently possible.

[ikitommi]

result of parse is actually a MapEntry. Clojure = matches it to vector of two elements. See https://github.com/metosin/malli/blob/master/src/malli/impl/util.cljc#L8-L9. But, I see this being a problem.