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build/packages/gleam_json/README.md

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+# json 🐑
+
+Work with JSON in Gleam!
+
+## Installation
+
+```shell
+gleam add gleam_json@3
+```
+
+## Encoding
+
+```gleam
+import myapp.{type Cat}
+import gleam/json
+
+pub fn cat_to_json(cat: Cat) -> String {
+  json.object([
+    #("name", json.string(cat.name)),
+    #("lives", json.int(cat.lives)),
+    #("flaws", json.null()),
+    #("nicknames", json.array(cat.nicknames, of: json.string)),
+  ])
+  |> json.to_string
+}
+```
+
+## Parsing
+
+JSON is parsed into a `Dynamic` value which can be decoded using the
+`gleam/dynamic/decode` module from the Gleam standard library.
+
+```gleam
+import myapp.{Cat}
+import gleam/json
+import gleam/dynamic/decode
+
+pub fn cat_from_json(json_string: String) -> Result(Cat, json.DecodeError) {
+  let cat_decoder = {
+    use name <- decode.field("name", decode.string)
+    use lives <- decode.field("lives", decode.int)
+    use nicknames <- decode.field("nicknames", decode.list(decode.string))
+    decode.success(Cat(name:, lives:, nicknames:))
+  }
+  json.parse(from: json_string, using: cat_decoder)
+}
+```