DotnetMarlowe

NOTE This library was created based on an older version of the Marlowe language and will not be able to parse moderns contracts.

Toy implementation for serializing and deserializing Cardano Marlowe smart contracts to and from F# DU types.

This project was created for experimenting with programatically generating (financial) smart contracts for Cardano using .NET/F# rather than having to use Haskell or Marlowe directly. It's just a toy implementation and should be treated as such..

Simple test runner

$ dotnet fsi script.fsx test
> samples/Contract_CouponBondGuaranteed.marlowe : OK
> samples/Contract_test.marlowe : OK
> samples/Contract_oraclediffs.marlowe : OK
> samples/Contract_diffs.marlowe : OK
> samples/Contract_swap.marlowe : OK
> samples/Contract_Escrow.marlowe : OK
> samples/Contract_ZeroCouponBond.marlowe : OK
> samples/Contract_EscrowWithCollateral.marlowe : OK
> samples/Contract_sample.marlowe : OK
> samples/Deposit_Sample.marlowe : OK

Parse a marlowe file and get the resulting F# object

$ dotnet fsi script.fsx samples/Deposit_Sample.marlowe
> Deserialization completed in: 15ms
------------------------------------------
Deposit
  (Role "Ada provider", Role "Ada provider", Token ("", ""),
   MulValue (Constant 1000000L, ConstantParam "Amount of Ada"))

Deserializing Marlowe contract into F#:

// raw marlowe dsl text
let sample = """
  When [
  (Case
     (Deposit
        (Role "Seller")
        (Role "Buyer")
        (Token "" "")
        (ConstantParam "Price"))
     (When [
           (Case
              (Choice
                 (ChoiceId "Everything is alright"
                    (Role "Buyer")) [
                 (Bound 0 0)]) Close)
           ,
           (Case
              (Choice
                 (ChoiceId "Report problem"
                    (Role "Buyer")) [
                 (Bound 1 1)])
              (Pay
                 (Role "Seller")
                 (Account
                    (Role "Buyer"))
                 (Token "" "")
                 (ConstantParam "Price")
                 (When [
                       (Case
                          (Choice
                             (ChoiceId "Confirm problem"
                                (Role "Seller")) [
                             (Bound 1 1)]) Close)
                       ,
                       (Case
                          (Choice
                             (ChoiceId "Dispute problem"
                                (Role "Seller")) [
                             (Bound 0 0)])
                          (When [
                                (Case
                                   (Choice
                                      (ChoiceId "Dismiss claim"
                                         (Role "Arbiter")) [
                                      (Bound 0 0)])
                                   (Pay
                                      (Role "Buyer")
                                      (Party
                                         (Role "Seller"))
                                      (Token "" "")
                                      (ConstantParam "Price") Close))
                                ,
                                (Case
                                   (Choice
                                      (ChoiceId "Confirm problem"
                                         (Role "Arbiter")) [
                                      (Bound 1 1)]) Close)] (SlotParam "Timeout for arbitrage") Close))] (SlotParam "Seller's response timeout") Close)))] (SlotParam "Buyer's dispute timeout") Close))] 123 Close
"""

// fancy pants f# typed contract object!
let myContract = sample |> dotnetmarlowe.Deserializer.DeserializeMarlowe<dotnetmarlowe.Types.Contract> 
myContract // Result:

When
  ([Case
      (Deposit
         (Role "Seller", Role "Buyer", Token ("", ""), ConstantParam "Price"),
       When
         ([Case
             (Choice
                (ChoiceId ("Everything is alright", Role "Buyer"),
                 [Bound (0L, 0L)]), Close);
           Case
             (Choice
                (ChoiceId ("Report problem", Role "Buyer"), [Bound (1L, 1L)]),
              Pay
                ((Role "Seller", Account (Role "Buyer"), Token ("", ""),
                  ConstantParam "Price"),
                 When
                   ([Case
                       (Choice
                          (ChoiceId ("Confirm problem", Role "Seller"),
                           [Bound (1L, 1L)]), Close);
                     Case
                       (Choice
                          (ChoiceId ("Dispute problem", Role "Seller"),
                           [Bound (0L, 0L)]),
                        When
                          ([Case
                              (Choice
                                 (ChoiceId ("Dismiss claim", Role "Arbiter"),
                                  [Bound (0L, 0L)]),
                               Pay
                                 ((Role "Buyer", Party (Role "Seller"),
                                   Token ("", ""), ConstantParam "Price"), Close));
                            Case
                              (Choice
                                 (ChoiceId ("Confirm problem", Role "Arbiter"),
                                  [Bound (1L, 1L)]), Close)],
                           SlotParam "Timeout for arbitrage", Close))],
                    SlotParam "Seller's response timeout", Close)))],
          SlotParam "Buyer's dispute timeout", Close))], SlotConstant 123L,
   Close)

Serializing F# DU's to Marlowe

myContract |> dotnetmarlowe.Serializer.serializeUnionTypeIntoMarlowe 
// result:
  When [
  (Case
     (Deposit
        (Role "Seller")
        (Role "Buyer")
        (Token "" "")
        (ConstantParam "Price"))
     (When [
           (Case
              (Choice
                 (ChoiceId "Everything is alright"
                    (Role "Buyer")) [
                 (Bound 0 0)]) Close)
           ,
           (Case
              (Choice
                 (ChoiceId "Report problem"
                    (Role "Buyer")) [
                 (Bound 1 1)])
              (Pay
                 (Role "Seller")
                 (Account
                    (Role "Buyer"))
                 (Token "" "")
                 (ConstantParam "Price")
                 (When [
                       (Case
                          (Choice
                             (ChoiceId "Confirm problem"
                                (Role "Seller")) [
                             (Bound 1 1)]) Close)
                       ,
                       (Case
                          (Choice
                             (ChoiceId "Dispute problem"
                                (Role "Seller")) [
                             (Bound 0 0)])
                          (When [
                                (Case
                                   (Choice
                                      (ChoiceId "Dismiss claim"
                                         (Role "Arbiter")) [
                                      (Bound 0 0)])
                                   (Pay
                                      (Role "Buyer")
                                      (Party
                                         (Role "Seller"))
                                      (Token "" "")
                                      (ConstantParam "Price") Close))
                                ,
                                (Case
                                   (Choice
                                      (ChoiceId "Confirm problem"
                                         (Role "Arbiter")) [
                                      (Bound 1 1)]) Close)] (SlotParam "Timeout for arbitrage") Close))] (SlotParam "Seller's response timeout") Close)))] (SlotParam "Buyer's dispute timeout") Close))] 123 Close