@hackage web30.3.2.0

Ethereum Haskell API

This is the Ethereum compatible Haskell API which implements the Generic JSON RPC spec.

Installation

$ git clone https://github.com/airalab/hs-web3 && cd hs-web3
$ stack setup
$ stack ghci

This library runs only paired with geth or parity Ethereum node, please start node first before using the library.

Web3 monad

Any Ethereum node communication wrapped with Web3 monadic type.

> :t web3_clientVersion
web3_clientVersion :: Web3 Text

To run this computation used runWeb3' or runWeb3 functions.

> runWeb3 web3_clientVersion
Right "Parity//v1.4.5-beta-a028d04-20161126/x86_64-linux-gnu/rustc1.13.0"

TemplateHaskell generator

Quasiquotation is used to parse contract ABI or load from JSON file. TemplateHaskell driven Haskell contract API generator can automatical create instances for Event and Method typeclasses and function helpers.

> :set -XQuasiQuotes
> putStr [abiFrom|data/sample.json|]
Contract:
        Events:
                Action1(address,uint256)
                Action2(string,uint256)
        Methods:
                0x03de48b3 runA1()
                0x90126c7a runA2(string,uint256)

See example of usage.

import Data.ByteArray (Bytes)
import Data.Text (Text)

[abiFrom|data/sample.json|]

main :: IO ()
main = do
    tx <- runWeb3 (runA2 addr nopay "Hello!" 42)
    print tx
  where addr = "0x19EE7966474b31225F71Ef8e36A71378a58a20E1"