I want to ensure that my contract contains a minimum of 4 parties as “Hawalla’s” So I imported DA Next Map with: import DA.Next.Map as NM and then added the ensure constraint, but I’m getting a parser error. I read the documentation for this module. I don’t think I’m using the key/value pairs cor…

@anthony ’s answer is going in the right direction, but, as I understand it, you not only want 4 parties, you want to verify that they are 4 different parties. We’ll need two new functions for that. The first one is DA.List.unique, which is True if there are no duplicates in the given list. The secon…

You want to use length to get the size of the list and then compare against that. Also the operation for comparing if an Int is greater than or equal to another would be >=. ensure length hawalla >= 4 I believe -> is only used for type definitions. Kind of an aside but one way to find out what fun…

[image] Gary_Verhaegen: but, as I understand it, you not only want 4 parties, you want to verify that they are 4 different parties. Yeah this is likely true and makes @Gary_Verhaegen ’s answer the right one for this usecase. Also worth noting is that `notElem` is using infix notation in the e…

Thank you very much for this detailed write-up @Gary_Verhaegen . I’m going to study each line in detail to get a full understanding. I’ve gotten the gist of the underlying thought process here anyhow which has really helped. You are right, I am going to need a proposal/accept pattern because the wh…

Also, I didn’t quite understand this line aliceTV <- submitMustFail alice do My confusion comes from the use of AliceTV , where did “AliceTV” come from or what is the significance of it?

Ah, my bad, this is a confusing mistake on my end. There should not be any aliceTV in this code snippet. As a more general answer, Daml code runs “next to” the ledger, but is not directly integrated with the ledger. This means that you have a notion of “asking things from the ledger”, and “getting …

Using a standard library module with constraints (map function)

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Using a standard library module with constraints (map function)

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