No instance for (Action Commands) arising from a do statement

New to Daml
1

The code copied from https://docs.daml.com/daml/intro/3_Data.html under the section titled Contract Keys throws this compilation error at the statement:

archiveCmd accountCid

Here is the full code:

module Main where

import Daml.Script
import DA.Assert (assertEq)

data Bank = Bank with
party : Party
address: Text
telephone : Text
deriving (Eq, Show)

template Account
with
accountant : Party
owner : Party
number : Text
bank : Bank
where
signatory accountant

data Cash = Cash with
currency : Text
amount : Decimal
deriving (Eq, Show)

template CashBalance
with
accountant : Party
cash : Cash
account : ContractId Account
where
signatory accountant

setup: Script()

setup = script do
accountant ← allocateParty “Bob”
owner ← allocateParty “Alice”
bank_party ← allocateParty “Bank”
let
bank = Bank with
party = bank_party
address = “High Street”
telephone = “012 3456 789”
cash = Cash with
currency = “USD”
amount = 100.0

accountCid <- submit accountant do
    createCmd Account with
        accountant
        owner
        bank
        number = "ABC123"

balanceCid <- submit accountant do
    createCmd CashBalance with
        accountant
        cash
        account = accountCid

-- Now the accountant updates the telephone number for the bank on the account
Some account <- queryContractId accountant accountCid
new_account <- submit accountant do
    archiveCmd accountCid
    createCmd account with
        bank = account.bank with
            telephone = "098 7654 321"
    pure ()

-- The `account` field on the balance now refers to the archived
-- contract, so this will fail.
Some balance <- queryContractId accountant balanceCid
optAccount <- queryContractId accountant balance.account
assertEq optAccount None

I made just one little change at the end where I replaced
optAccount === None
with
assertEq optAccount None

Here is the complete error message:

No instance for (Action Commands) arising from a do statement
• In a stmt of a ‘do’ block: archiveCmd accountCid
In the second argument of ‘submit’, namely
‘do archiveCmd accountCid
createCmd
(setField
@“bank”
((setField
@“telephone” (“098 7654 321”) (getField @“bank” account)))
account)
pure ()’
In a stmt of a ‘do’ block:

Will really appreciate some hints in what could I be doing wrong!

1 Like
2

One little change compared to what? Where does the code come from? It’s pretty hard to read as it stands, would you mind reposting it in-between triple quotes?

1 Like
3

Hi @Neelam_Dwivedi, this happens if you do not enable ApplicativeDo. To fix it, add the following to the very top of your file (above module).

{-# LANGUAGE ApplicativeDo #-}

You can find more info on this in the daml script documentation.

4

Sorry about that @Gary_Verhaegen! Re-pasted the code I copied from Docs.

data Bank = Bank with
  party : Party
  address: Text
  telephone : Text
    deriving (Eq, Show)

template Account
  with
    accountant : Party
    owner : Party
    number : Text
    bank : Bank
  where
    signatory accountant

data Cash = Cash with
  currency : Text
  amount : Decimal
    deriving (Eq, Show)

template CashBalance
  with
    accountant : Party
    cash : Cash
    account : ContractId Account
  where
    signatory accountant

id_ref_test = do
  accountant <- allocateParty "Bob"
  owner <- allocateParty "Alice"
  bank_party <- allocateParty "Bank"
  let
    bank = Bank with
      party = bank_party
      address = "High Street"
      telephone = "012 3456 789"
    cash = Cash with
      currency = "USD"
      amount = 100.0

  accountCid <- submit accountant do
     createCmd Account with
      accountant
      owner
      bank
      number = "ABC123"

  balanceCid <- submit accountant do
    createCmd CashBalance with
      accountant
      cash
      account = accountCid

  -- Now the accountant updates the telephone number for the bank on the account
  Some account <- queryContractId accountant accountCid
  new_account <- submit accountant do
    archiveCmd accountCid
    createCmd account with
      bank = account.bank with
        telephone = "098 7654 321"
    pure ()

  -- The `account` field on the balance now refers to the archived
  -- contract, so this will fail.
  Some balance <- queryContractId accountant balanceCid
  optAccount <- queryContractId accountant balance.account
  optAccount === None
1 Like
5

Thanks @cocreature !! This works!