https://github.com/iravid/play-json-cats

cats typeclass instances for play-json
https://github.com/iravid/play-json-cats

cats functional-programming json play-json scala

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cats typeclass instances for play-json

• Host: GitHub
• URL: https://github.com/iravid/play-json-cats
• Owner: iravid
• License: apache-2.0
• Created: 2017-01-23T18:54:30.000Z (almost 8 years ago)
• Default Branch: master
• Last Pushed: 2020-03-11T22:12:05.000Z (almost 5 years ago)
• Last Synced: 2024-04-01T01:50:19.166Z (10 months ago)
• Topics: cats, functional-programming, json, play-json, scala
• Language: Scala
• Homepage:
• Size: 37.1 KB
• Stars: 6
• Watchers: 2
• Forks: 5
• Open Issues: 2
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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# play-json-cats

`cats` typeclass instances for the `play-json` library.

## Adding as a dependency to your project

```scala

libraryDependencies += "com.iravid" %% "play-json-cats" % 1.1.0

```

`play-json-cats` is cross-published for Scala 2.11 and 2.12.

## Usage

```scala

import cats.implicits._

import com.iravid.playjsoncats.implicits._

import play.api.libs.json._

case class Person(name: String, i: Int)

val rn: Reads[String] = Reads(j => (j \ "name").validate[String])

val ri: Reads[Int] = Reads(j => (j \ "i").validate[Int])

val rp: Reads[Person] = (rn, rp).mapN(Person)

val res: JsResult[Person] = rp.reads(Json.parse("""

  { "name": "iravid", "i": 42 }

"""))

```

## Provided instances

| `play-json` type | provided instances                            |

|------------------|-----------------------------------------------|

| `Reads[A]`       | `Functor`, `Applicative`, `Monad`             |

| `Writes[A]`      | `Contravariant`                               |

| `Format[A]`      | `Invariant`                                   |

| `JsResult[A]`    | `Functor`, `Applicative`, `ApplicativeError`  |

|                  | `Monad`, `MonadError`, `Traverse`,            |

|                  | `Monoid` (for `A: Monoid`)                    |