[cheshire "5.13.0"]

;; Cheshire v5.13.0 uses Jackson 2.17.0

;; In your ns statement:
(ns my.ns
  (:require [cheshire.core :refer :all]))

;; generate some json
(generate-string {:foo "bar" :baz 5})

;; write some json to a stream
(generate-stream {:foo "bar" :baz 5} (clojure.java.io/writer "/tmp/foo"))

;; generate some SMILE
(generate-smile {:foo "bar" :baz 5})

;; generate some JSON with Dates
;; the Date will be encoded as a string using
;; the default date format: yyyy-MM-dd'T'HH:mm:ss'Z'
(generate-string {:foo "bar" :baz (java.util.Date. 0)})

;; generate some JSON with Dates with custom Date encoding
(generate-string {:baz (java.util.Date. 0)} {:date-format "yyyy-MM-dd"})

;; generate some JSON with pretty formatting
(generate-string {:foo "bar" :baz {:eggplant [1 2 3]}} {:pretty true})
;; {
;;   "foo" : "bar",
;;   "baz" : {
;;     "eggplant" : [ 1, 2, 3 ]
;;   }
;; }

;; generate JSON escaping UTF-8
(generate-string {:foo "It costs £100"} {:escape-non-ascii true})
;; => "{\"foo\":\"It costs \\u00A3100\"}"

;; generate JSON and munge keys with a custom function
(generate-string {:foo "bar"} {:key-fn (fn [k] (.toUpperCase (name k)))})
;; => "{\"FOO\":\"bar\"}"

;; generate JSON without escaping the characters (by writing it to a file)
(spit "foo.json" (json/generate-string {:foo "bar"} {:pretty true}))

(let [my-pretty-printer (create-pretty-printer
                          (assoc default-pretty-print-options
                                 :indent-arrays? true))]
  (generate-string {:foo [1 2 3]} {:pretty my-pretty-printer}))

;; parse some json
(parse-string "{\"foo\":\"bar\"}")
;; => {"foo" "bar"}

;; parse some json and get keywords back
(parse-string "{\"foo\":\"bar\"}" true)
;; => {:foo "bar"}

;; parse some json and munge keywords with a custom function
(parse-string "{\"foo\":\"bar\"}" (fn [k] (keyword (.toUpperCase k))))
;; => {:FOO "bar"}

;; top-level strings are valid JSON too
(parse-string "\"foo\"")
;; => "foo"

;; parse some SMILE (keywords option also supported)
(parse-smile <your-byte-array>)

;; parse a stream (keywords option also supported)
(parse-stream (clojure.java.io/reader "/tmp/foo"))

;; parse a stream lazily (keywords option also supported)
(parsed-seq (clojure.java.io/reader "/tmp/foo"))

;; parse a SMILE stream lazily (keywords option also supported)
(parsed-smile-seq (clojure.java.io/reader "/tmp/foo"))

;; In this example a function that checks for a certain key
(decode "{\"myarray\":[2,3,3,2],\"myset\":[1,2,2,1]}" true
        (fn [field-name]
          (if (= field-name "myset")
            #{}
            [])))
;; => {:myarray [2 3 3 2], :myset #{1 2}}

;; Custom encoders allow you to swap out the api for the fast
;; encoder with one that is slightly slower, but allows custom
;; things to be encoded:
(ns myns
  (:require [cheshire.core :refer :all]
            [cheshire.generate :refer [add-encoder encode-str remove-encoder]]))

;; First, add a custom encoder for a class:
(add-encoder java.awt.Color
             (fn [c jsonGenerator]
               (.writeString jsonGenerator (str c))))

;; There are also helpers for common encoding actions:
(add-encoder java.net.URL encode-str)

;; List of common encoders that can be used: (see generate.clj)
;; encode-nil
;; encode-number
;; encode-seq
;; encode-date
;; encode-bool
;; encode-named
;; encode-map
;; encode-symbol
;; encode-ratio

;; Then you can use encode from the custom namespace as normal
(encode (java.awt.Color. 1 2 3))
;; => "java.awt.Color[r=1,g=2,b=3]"

;; Custom encoders can also be removed:
(remove-encoder java.awt.Color)

;; Decoding remains the same, you are responsible for doing custom decoding.

(ns foo.bar
  (require [cheshire.core :as json]
           [cheshire.parse :as parse]))

(json/decode "111111111111111111111111111111111.111111111111111111111111111111111111")
;; => 1.1111111111111112E32 (a Double)

(binding [parse/*use-bigdecimals?* true]
  (json/decode "111111111111111111111111111111111.111111111111111111111111111111111111"))
;; => 111111111111111111111111111111111.111111111111111111111111111111111111M (a BigDecimal)

(ns myns
  (:require [cheshire.core :as core]
            [cheshire.factory :as factory]))

(binding [factory/*json-factory* (factory/make-json-factory
                                  {:allow-non-numeric-numbers true})]
  (json/decode "{\"foo\":NaN}" true))))))