The Problem of Effects (2020)

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  • ponyc

    :horse: Pony is an open-source, actor-model, capabilities-secure, high performance programming language

    There are several languages that are working on solving the composable effects problem that I am aware of:

    * Pony - capabilities based language inspired by `E`. Effects are like Rust's (provided by the language, not extensible by end users):

    * Koka - effects are first class and higher order. `filter` is a higher order function that is "effectfully parameterized" as well as "parameterized over its types". Effects can be discharged at any level of the program and the effects "stack" is manipulable (in what appears to be a principled way)

    * Multi-core OCaml is also building parallelism on a version of effects that looks quite a lot like Koka (though I'm not familiar enough with it to say how close they are in practice).

    What other ones am I missing?

  • eff

    🚧 a work in progress effect system for Haskell 🚧 (by hasura)

    Let me tell you what I'm worried about with effects systems: One of the smartest people I know of has a library called Eff that efficiently implements effects through some modifications to GHC. The thing is, she's pretty much stopped working on because she found some really nasty semantic edge-cases that she couldn't resolve to her satisfaction. (I don't understand the problems well enough to describe them, and I think they're specific to lazy languages, but it has left me cautious about the effect model in general.)

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  • frank

    Frank compiler (by frank-lang)

  • ghc-proposals

    Proposed compiler and language changes for GHC and GHC/Haskell (by nicuveo)

    What makes you say it ran aground? I thought it was just waiting for [0].


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    A Proof-oriented Programming Language

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