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What is the '$' operator?

I come across some examples in the Daml documentation where the operator '$' is being used, but cannot fully understand its purpose.

Example:

submit alice $ create User with username = alice, following = []

Is it the same as do, like in:

submit alice do
  create User with username = alice, following = []

?

Solution

  • The $ operator is a substitute for parenthesis. The example

    submit alice $ create User with username = alice, following = []

    is the same as

    submit alice (create User with username = alice, following = [])

    To complete, the do is used to declare a code block (more than one line of code):

    test = scenario do
  alice <- getParty "Alice"
  bob <- getParty "Bob"
  ...

    However, it can also be used in a single line of code:

    submit alice do create User with username = alice, following = []