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Unison

A new approach to

Distributed programming

No more writing encoders and decoders at every network boundary. Say where you want computations to run and it happens 🔮 — Dependencies are deployed on the fly.

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Refactoring

Your codebase is always live and typechecks, even in the middle of a refactoring. Unison has structured refactoring sessions, not a big misleading list of type errors.

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Durable storage

No more writing translation code between your values and the storage layer. Directly store values and unpersist them later without fear of dependency conflicts or version mismatches.

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Storing code

Other tools try to recover structure from text; Unison stores code in a database. This eliminates builds, provides for instant nonbreaking renames, type-based search, and lots more.

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Dependencies

Many dependency conflicts arise from definitions competing for the same names. Since Unison references code by hash instead of by name, an entire class of conflicts can be eliminated.

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Unison is a friendly programming language from the future: statically-typed, functional, and a lot of fun 😄

On Apple Silicon? You'll need Rosetta to run Unison.

Download the latest release from GitHub

How does Unison code look?

💡 All parts of the code examples are interactive. Click a dependency to read its definition and docs.

👋 Hello World

The classic Hello World program in Unison is as simple as a call to printLine.

helloWorld : '{IO, Exception} ()

helloWorld : '{IO, Exception} ()
helloWorld _ = printLine "Hello World"

{IO, Exception}indicates which abilities the program needs to do I/O and throw exceptions.

'

is used to denote a delayed computation.

Learn more about Abilities.

Distributed map-reduce

With a few lines of code, you can perform a distributed map-reduce using thelib.distributed.Remoteability.

distributedEx : lib.distributed.Seq k Nat
                ->{lib.distributed.Remote} Nat

distributedEx :
  lib.distributed.Seq k Nat ->{lib.distributed.Remote} Nat
distributedEx dseq =
  dseq
    |> lib.distributed.Seq.map (x -> x + 1)
    |> lib.distributed.Seq.filter (x -> mod x 7 == 0)
    |> lib.distributed.Seq.reduce 0 (+)

Learn more about Remote and working withdistributed datasets in Unison.

HTTP request

Perform effectful code, like HTTP requests withAbilitiesandAbility handlers.

Checkout more HTTP examples in thehttp library.

httpEx : '{IO, Exception} Response

httpEx : '{IO, Exception} Response
httpEx _ =
  host = HostName "unison-lang.org"
  web = Authority None host None
path = Path.root / "learn"
  uri = Uri.Uri Scheme.https (Some web) path http.Query.empty None
  req = Request.get uri
  handle http.Http.request req with http.Http.handler

What's it like to write Unison code?

The Unison Codebase Manager (UCM) is by your side as you write, guiding you through the
development process; adding, updating, and running your programs.

Editor : ~/scratch.u

Terminal : UCM - Unison Codebase Manager

👋 Welcome to Unison!

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