CODEWITHSUNDEEP
constructorpattern-matchingocamlequality
zeronone
zeronone

Reputation: 3041

Type Constructor equality in OCaml

I am new to OCaml. I am trying to look for a way to check the equality of constructor types (union types ?) in the pattern matching. 

type team = BRAZIL | KOREA;;
type tourn = LEAF of team | NODE of tourn * tourn ;;
let iter t d = 
  match t with 
    NODE ( (LEAF k), (LEAF i) ) when k = d -> "Yes"
  | _                                      -> "No"
;;

iter (NODE ( (LEAF KOREA), (LEAF BRAZIL) ) KOREA         (* returns "No" *)

Upvotes: 0

Views: 200

Answers (1)

Kakadu
Kakadu

Reputation: 2839

It works OK, but you test it wrong. If you look again in last line you will see that ) is missing.

 # iter (NODE (LEAF KOREA, LEAF BRAZIL)) KOREA ;;
 - : string = "Yes"

Upvotes: 2

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