https://github.com/nytimes/jsonlogic

https://github.com/nytimes/jsonlogic

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• Host: GitHub
• URL: https://github.com/nytimes/jsonlogic
• Owner: nytimes
• License: other
• Created: 2022-01-20T18:43:49.000Z (almost 3 years ago)
• Default Branch: main
• Last Pushed: 2022-04-07T18:51:39.000Z (over 2 years ago)
• Last Synced: 2024-10-12T06:28:51.128Z (2 months ago)
• Language: Clojure
• Size: 34.2 KB
• Stars: 21
• Watchers: 4
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE
  • Code of conduct: CODE_OF_CONDUCT.md
  • Security: SECURITY.md

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• stars - nytimes/jsonlogic - (⭐️21) (Clojure)
• stars - nytimes/jsonlogic - (⭐️21) (Clojure)

README

        
# JsonLogic

[![Clojars Project](https://img.shields.io/clojars/v/com.nytimes/jsonlogic.svg)](https://clojars.org/com.nytimes/jsonlogic)

[![Build Status](https://cloud.drone.io/api/badges/nytimes/jsonlogic/status.svg?ref=refs/heads/main)](https://cloud.drone.io/nytimes/jsonlogic)

A [jsonlogic][1] implementation for Clojure.

## Installation

```clojure

[com.nytimes/jsonlogic "1.0.0"]

```

## Usage

```clojure

(require '[com.nytimes.jsonlogic :as jsonlogic])

(jsonlogic/apply {:if [true "Foo" "Bar"]})

"Foo"

```

This library supports encoding the operators as keywords, string, or symbols.

All of these values are coerced to symbols for evalution..

```clojure

(jsonlogic/apply {"+" [1 2]})

;;=> 3

(jsonlogic/apply {:+ [1 2]})

;;=> 3

(jsonlogic/apply {'+ [1 2]})

;;=> 3

```

## Extending JsonLogic

You can add custom JsonLogic operations by extending the `operate` multi-method.

### Arguments

Operate receives two arguments, a map of the operation and the data provided to

apply. For example, given this invocation:

```clojure

(jsonlogic/apply {"*" [{"var" "x"} {"var" "x"}]}

                 {"x" 2})

```

The arguments to `*` are:

1. `{* [{var "x"} {var "x"}]}`

2. `{"x" 2}`

### A Custom Operator Example

Here is an example of adding a custom power function.

```clojure

(require '[com.nytimes.jsonlogic :as json])

(require '[clojure.math :as math])

(defmethod jsonlogic/operate '**

  [{args '**} _env]

  (if (not= 2 (count args))

    (throw (ex-info "** requires exactly two arguments" {:args args}))

    (let [[base exponent] args]

      (math/pow base exponent))))

(jsonlogic/apply {'** [2 3]})

;;=> 8.0

```

[1]: https://jsonlogic.com/