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Polycademy / Verify

Polyglot Validation and Filtering Service
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Rules Engine #2

Open CMCDragonkai opened 9 years ago

CMCDragonkai commented 9 years ago

We should write this in Mercury.

Should it be embeddable?

CMCDragonkai commented 9 years ago

http://www.mercurylang.org/documentation/papers/fpu_rules_2009.pdf

CMCDragonkai commented 9 years ago

Perhaps something like creating C extensions?

Or shell out?

Or IPC?

CMCDragonkai commented 9 years ago

Consider if the rules engine needs to interact with state. State that is held elsewhere, then it would need data access requirements.

Instead, make the rules engine ask questions. You can pass it data, but it will return asking questions. Depending on these questions, the asker needs to supply answers, so the rules engine can finish. It needs a somewhat chatty IPC technique.

CMCDragonkai commented 9 years ago

Should a rules engine take rules as its own language, or use a schema language?

CMCDragonkai commented 9 years ago

This would require a bidirectional messaging protocol. Both client and server need to use one socket or 2 sockets and send and receive on them.

Something like:

Process -> start session (initial)
        <- response (ok) (response)

        <- question 1 (initial)
        -> answer 1 (response)
        <- question 2
        -> answer 2

        <- done, with success/errors
        -> ack (finish session)

Options include socketpair, ZMQ pair, Capnproto bidirectional RPC,

Doing this requires either non-blocking IO or using 2 lightweight threads one to send and one to receive, but then cross thread communication.

Erlang is another options.

Erlog looks like something that can embed Prolog as an erlang process. Then the erlang program will need to communicate to external clients using a chatty protocol like socketpair.

https://github.com/rvirding/erlog

Who knew bidirectional IPC was so hard?

The verification server needs to send questions to the client to answer.

See these:

CMCDragonkai commented 9 years ago

An alternative to using logic languages and schema is to use Schema in Clojure: https://github.com/Prismatic/schema

CMCDragonkai commented 9 years ago

This like distributed or outsourced dependent type checking. Outsource your dependent types to verify!