Crowd

Main.hs

{-# LANGUAGE OverloadedStrings #-}
module Example where

import           Data.List        (foldl')
import           Language.Marlowe

main :: IO ()
main = print . pretty $ contract


{- Define a contract, Close is the simplest contract which just ends the contract straight away
-}

contract :: Contract
contract = crowd 1000 500 "Dora" ["Alice", "Bob", "Charlie"] 10

crowd :: Integer  -- ^ campaign goal
      -> Integer  -- ^ individual contribution
      -> Party    -- ^ campaign owner
      -> [Party]  -- ^ contributors
      -> Slot     -- ^ deadline
      -> Contract
crowd goal c owner contributors deadline
    = go [] contributors
  where
    go :: [Party] -> [Party] -> Contract
    go ys ns =
        When
            [Case (Deposit n n ada $ Constant c) $
                go (n : ys) $ filter (/= n) ns | n <- ns]
            deadline $ settle ys

    settle :: [Party] -> Contract
    settle ys
        | fromIntegral (length ys) * c >= goal  = foldl' pay Close ys
        | otherwise                             = Close

    pay :: Contract -> Party -> Contract
    pay x p = Pay p (Party owner) ada (Constant c) x

playground.marlowe.json

{}