Ill formed storage type in origination

Question

Attempted to originate a contract but getting a storage type error when trying to originate it

Error: proto.005-PsBabyM1.michelson_v1.ill_formed_type
Error: proto.005-PsBabyM1.michelson_v1.invalid_arity


              {
                "kind": "permanent",
                "id": "proto.005-PsBabyM1.michelson_v1.invalid_arity",
                "location": 16,
                "primitive_name": "key",
                "expected_arity": 0,
                "wrong_arity": 0
              }



storage   (pair (pair (list %owners key) (nat %threshold)) (map %txRecords string (pair (pair (pair (pair (mutez %amount) (bytes %needSignData)) (set %signers key)) (address %to)) (string %txId))))

Could someone please help me understand why this storage type is ill defined ?

The original contract which led to this error was written in smartpy: https://tinyurl.com/v9x9cuj

Answer 1

The problem lies in this part (set %signers key). The set requires that its elements are comparable, but key type is not comparable. To get around this, you could use key_hash for the set instead, which is comparable and you can compute it from key.

For details:

• Michelson full grammar
• Michelson reference