composite-dhall: Dhall instances for composite records.

[ composite, data, dhall, library, mit ] [ Propose Tags ]

Dhall instances for composite records.


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Versions [RSS] 0.0.1.0, 0.0.2.0, 0.0.3.0, 0.0.4.0, 0.0.4.1, 0.0.6.0, 0.1.0.0, 0.1.0.1
Change log ChangeLog.md
Dependencies base (>=4.7 && <5), composite-base (>=0.7.0.0 && <0.8), dhall (>=1.34.0 && <1.40), text (>=1.0 && <1.4), vinyl [details]
License MIT
Copyright 2021 Daniel Firth
Author Daniel Firth
Maintainer dan.firth@homotopic.tech
Category Dhall
Source repo head: git clone https://gitlab.homotopic.tech/haskell/composite-dhall
Uploaded by locallycompact at 2021-08-09T13:09:29Z
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Downloads 915 total (19 in the last 30 days)
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Status Docs available [build log]
All reported builds failed as of 2021-08-09 [all 1 reports]

Readme for composite-dhall-0.0.2.0

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composite-dhall

ToDhall and FromDhall instances for composite records.

You can deserialise a normal dhall record such as

{ a = "foo"
, b = +5 }

using a Record like:

withLensesAndProxies
  [d|
    type A = "a" :-> Text

    type B = "b" :-> Int
    |]

type MyRec = Record '[A, B]

Similarly you can use a contravariant function as the base functor to parse a collection of templates for different types.

{ a = \(x : Text) -> "Hello ${x}."
, b = \(y : Integer) -> "You are ${Integer/show y} years old."
}

We use a DerivingVia to avoid overlapping instances in composite:

newtype Template a = Template (Op Text a)
  deriving newtype (FromDhall)

newtype Templates = Templates {unTemplates :: Rec Template '[A, B]}
  deriving (FromDhall) via (Rec (Op Text) '[A, B])