Digital Asset Open Sources Its Smart Contract Language, DAML [pdf] | Hacker News Reader

Digital Asset Open Sources Its Smart Contract Language, DAML [pdf]

hub.digitalasset.com

54 pointsPDiMarzio19 comments

Repository is at https://github.com/digital-asset/daml

Interesting... given that this is actually in use for the Australian Stock Exchange and the Hong Kong Exchanges, this smart contract language could become a major player and continue to get corporate adoption, especially now that it's open sourced.

The DAML landing page gives a nice overview of the unique language features:

https://daml.com/

Disclaimer: I work there. Very exciting to see it open-sourced!

Question: How do smart contracts handle defaults?

e.g. day1: ledger A and B strike a deal to bet on the 6M Libor fix in 3 months time. day 91: Libor fixes much higher than expected thanks to a continually robust IPO market and strong economy (but mostly the former.

In any event Ledger A now owes B 1,000 coins, but A only has 250 coins in its ledger. What happens? Is a partial payment done, or because this is a smart contract a Slack message is automagically sent to lawyers and/or collection agents?

This is a great question that will probably get better traction if asked through one of the DAML support channels... SO (https://stackoverflow.com/questions/tagged/daml) or Slack (https://damldriven.slack.com/).

Smart contracts on public blockchains solve this by committing coins to the contract. In effect the contract is an escrow facility in which the coins are locked up until the contract terminates.

The advantage of e.g. Ethereum blockchains is that defaults don't happen the assets are held by the contract. The drawback is that your assets are locked up for the duration of the contract, which is completely incompatible with how wholesale finance operates.

DAML's genesis was in solving this problem on private ledgers used for mediating inter-party value exchange of off-ledger assets (like dollars). To do that, rather than having an account or asset focus, it's built around the notion of rights, obligations, and enforcing a legally-compatible approach to contractual consent.

That is so that, when a "workflow" (e.g. your LIBOR swap) terminates, DAML provides a fully audited record of all the parties' agreement to be bound by the terms and consequences of the workflow itself. All being well there's an exchange of assets off-ledger. If things turn out badly, you go to court and the default is worked out with the backing of a rock-solid audit trail of affirmation (instead of a loose-leaf binder of printed emails and a dog-eared ISDA agreement.)

(I work for DA.)

> Smart contracts on public blockchains solve this by committing coins to the contract. In effect the contract is an escrow facility in which the coins are locked up until the contract terminates.

So if this is true, one could never write a call option on Ethereum because the downside risk for the writer is unbounded and you cannot put infinite coins in escrow.

As an aside, given the escrow component, there seems to be no credit/counterparty risk in any ETH smart contract, but for the most part if there is not risk transfer or sharing is there really any commerce to do?

Smart contract languages look still in infancy as practical applications are audit trails with stronger guarantees and lower operating costs. What you are thinking of sounds like a far more advanced deal management system. Besides, is it even possible to invent a way to trade risk in such a way that if one party hold unbounded exposure before the trade then after the trade both parties have bounded exposure? does it even make sense to have unbounded risks in system that is inescapably formal and will hold a bounded amount of money at each time? One could argue that risks that look unbounded are usually (as in without a ledger) handled less formally (ie: state bailout, https://www.forbes.com/sites/jamesconca/2016/03/10/after-fiv...) (Disclaimer: I work for Bloomberg on DLIB BLAN that is a contract language for structuring, pricing and managing exotic derivatives, no block-chains involved)

I was reading the Wikipedia[1] article about smart contracts, I still don't know what a smart contract is.

[1] https://en.wikipedia.org/wiki/Smart_contract

Smart contracts are programs whose computation is run independently across a large number of distributed machines, with an output that is verified using a predetermined consensus mechanism.

They are useful is situations where an actor would benefit from altering the result of the computation, or masking values. The primary use case that I've seen is for escrow payments with Ether, the Ethereum blockchain's native currency.

They trade processing speed for finality and verification of results.

Could not find what targets does it support, and are features identical between them?

At this very moment, DAML applications run on the DA ledger. Open sourcing the language is the first step in expanding that base. We (yes, I work at DA!) have been working with key ledger providers and will be making additional announcements over time - perhaps starting within the month if all goes well.

So is the idea that it's abstracted from the ledger, basically meaning you have your choice of whether you would run it in some centralized ledger secured within your company or on a more blockchainey distributed ledger on the public internet?

Yup!

Interesting, it looks a lot like Haskell. And Edward Kmett used to work there right? Could someone comment on its relationship with Haskell and the ML languages? Which I assume is the ML in DAML

Yes Edward was a big contributor here (full disclosure - I work at DA). A lot of our engineers, like Edward, come from the Haskell community. DAML uses the GHC compiler under the covers. One way to think of is is a GHC frontend that adds the extra bits required to streamline the task of writing multipartry contracts.

To answer the other part of your question, DAML stands for Digital Asset Modeling Language. No relationship with ML (apart from its influence in functional programming, of course).

Removed!!!

Aside from being a blatant marketing attempt, you should seriously stop overusing hashtags like this outside of Twitter.

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