JSON

A type representing a JSON object.

parseExn(string)

Parses a JSON string or throws a JavaScript exception (SyntaxError), if the string isn't valid. It returns a JSON type.

Examples

RESCRIPT
try {
  let _ = JSON.parseExn(`{"foo":"bar","hello":"world"}`)
  // { foo: 'bar', hello: 'world' }

  let _ = JSON.parseExn("")
  // error
} catch {
| Exn.Error(obj) => Console.log("error")
}

Exceptions

• Raises a SyntaxError (Exn.t) if the string isn't valid JSON.

parseExnWithReviver(string, reviver)

Parses a JSON string or throws a JavaScript exception (SyntaxError), if the string isn't valid. The reviver describes how the value should be transformed. It is a function which receives a key and a value. It returns a JSON type.

Examples

RESCRIPT
let reviver = (key, value) => {
  let valueType = JSON.Classify.classify(value)

  switch valueType {
  | String(string) => string->String.toUpperCase->JSON.Encode.string
  | Number(number) => (number *. 2.0)->JSON.Encode.float
  | _ => value
  }
}

let jsonString = `{"hello":"world","someNumber":21}`

try {
  JSON.parseExnWithReviver(jsonString, reviver)->Console.log
  // { hello: 'WORLD', someNumber: 42 }

  JSON.parseExnWithReviver("", reviver)->Console.log
  // error
} catch {
| Exn.Error(_) => Console.log("error")
}

Exceptions

• Raises a SyntaxError if the string isn't valid JSON.

stringify(json)

Converts a JSON object to a JSON string. If you want to stringify any type, use JSON.stringifyAny instead.

Examples

RESCRIPT
let json =
  Dict.fromArray([
    ("foo", JSON.Encode.string("bar")),
    ("hello", JSON.Encode.string("world")),
    ("someNumber", JSON.Encode.int(42)),
  ])->JSON.Encode.object

JSON.stringify(json)
// {"foo":"bar","hello":"world","someNumber":42}

stringifyWithIndent(json, indentation)

Converts a JSON object to a JSON string. The output will be indented. If you want to stringify any type, use JSON.stringifyAnyWithIndent instead.

Examples

RESCRIPT
let json =
  Dict.fromArray([
    ("foo", JSON.Encode.string("bar")),
    ("hello", JSON.Encode.string("world")),
    ("someNumber", JSON.Encode.int(42)),
  ])->JSON.Encode.object

JSON.stringifyWithIndent(json, 2)
// {
//   "foo": "bar",
//   "hello": "world",
//   "someNumber": 42
// }

stringifyWithReplacer(json, replacer)

Converts a JSON object to a JSON string. The replacer describes how the value should be transformed. It is a function which receives a key and a value. If you want to stringify any type, use JSON.stringifyAnyWithReplacer instead.

Examples

RESCRIPT
let json =
  Dict.fromArray([
    ("foo", JSON.Encode.string("bar")),
    ("hello", JSON.Encode.string("world")),
    ("someNumber", JSON.Encode.int(42)),
  ])->JSON.Encode.object

let replacer = (key, value) => {
  let decodedValue = value->JSON.Decode.string

  switch decodedValue {
  | Some(string) => string->String.toUpperCase->JSON.Encode.string
  | None => value
  }
}

JSON.stringifyWithReplacer(json, replacer)
// {"foo":"BAR","hello":"WORLD","someNumber":42}

stringifyWithReplacerAndIndent(json, replacer, indentation)

Converts a JSON object to a JSON string. The output will be indented. The replacer describes how the value should be transformed. It is a function which receives a key and a value. If you want to stringify any type, use JSON.stringifyAnyWithReplacerAndIndent instead.

Examples

RESCRIPT
let json =
  Dict.fromArray([
    ("foo", JSON.Encode.string("bar")),
    ("hello", JSON.Encode.string("world")),
    ("someNumber", JSON.Encode.int(42)),
  ])->JSON.Encode.object

let replacer = (key, value) => {
  let decodedValue = value->JSON.Decode.string

  switch decodedValue {
  | Some(string) => string->String.toUpperCase->JSON.Encode.string
  | None => value
  }
}

JSON.stringifyWithReplacerAndIndent(json, replacer, 2)
// {
  "foo": "BAR",
  "hello": "WORLD",
  "someNumber": 42
}

stringifyWithFilter(json, filter)

Converts a JSON object to a JSON string. The filter is an array of keys, which should be included in the output. If you want to stringify any type, use JSON.stringifyAnyWithFilter instead.

Examples

RESCRIPT
let json =
  Dict.fromArray([
    ("foo", JSON.Encode.string("bar")),
    ("hello", JSON.Encode.string("world")),
    ("someNumber", JSON.Encode.int(42)),
  ])->JSON.Encode.object

JSON.stringifyWithFilter(json, ["foo", "someNumber"])
// {"foo":"bar","someNumber":42}

stringifyWithFilterAndIndent(json, filter, indentation)

Converts a JSON object to a JSON string. The output will be indented. The filter is an array of keys, which should be included in the output. If you want to stringify any type, use JSON.stringifyAnyWithFilterAndIndent instead.

Examples

RESCRIPT
let json =
  Dict.fromArray([
    ("foo", JSON.Encode.string("bar")),
    ("hello", JSON.Encode.string("world")),
    ("someNumber", JSON.Encode.int(42)),
  ])->JSON.Encode.object

JSON.stringifyWithFilterAndIndent(json, ["foo", "someNumber"], 2)
// {
//   "foo": "bar",
//   "someNumber": 42
// }

stringifyAny(any)

Converts any type to a JSON string. Stringifying a function or undefined will return None. If the value contains circular references or BigInts, the function will throw a JavaScript exception (TypeError). If you want to stringify a JSON object, use JSON.stringify instead.

Examples

RESCRIPT
let dict = Dict.fromArray([
  ("foo", JSON.Encode.string("bar")),
  ("hello", JSON.Encode.string("world")),
  ("someNumber", JSON.Encode.int(42)),
])

JSON.stringifyAny(dict)
// {"foo":"bar","hello":"world","someNumber":42}

JSON.stringifyAny(() => "hello world")
// None

BigInt.fromInt(0)->JSON.stringifyAny
// exception

Exceptions

• Raises a TypeError if the value contains circular references.

• Raises a TypeError if the value contains BigInts.

stringifyAnyWithIndent(any, indentation)

Converts any type to a JSON string. The output will be indented. Stringifying a function or undefined will return None. If the value contains circular references or BigInts, the function will throw a JavaScript exception (TypeError). If you want to stringify a JSON object, use JSON.stringifyWithIndent instead.

Examples

RESCRIPT
let dict = Dict.fromArray([
  ("foo", JSON.Encode.string("bar")),
  ("hello", JSON.Encode.string("world")),
  ("someNumber", JSON.Encode.int(42)),
])

JSON.stringifyAnyWithIndent(dict, 2)
// {
//   "foo": "bar",
//   "hello": "world",
//   "someNumber": 42
// }

JSON.stringifyAny(() => "hello world")
// None

BigInt.fromInt(0)->JSON.stringifyAny
// exception

Exceptions

• Raises a TypeError if the value contains circular references.

• Raises a TypeError if the value contains BigInts.

stringifyAnyWithReplacer(json, replacer)

Converts any type to a JSON string. The replacer describes how the value should be transformed. It is a function which receives a key and a value. Stringifying a function or undefined will return None. If the value contains circular references or BigInts, the function will throw a JavaScript exception (TypeError). If you want to stringify a JSON object, use JSON.stringifyWithReplacer instead.

Examples

RESCRIPT
let dict = Dict.fromArray([
  ("foo", JSON.Encode.string("bar")),
  ("hello", JSON.Encode.string("world")),
  ("someNumber", JSON.Encode.int(42)),
])

let replacer = (key, value) => {
  let decodedValue = value->JSON.Decode.string

  switch decodedValue {
  | Some(string) => string->String.toUpperCase->JSON.Encode.string
  | None => value
  }
}

JSON.stringifyAnyWithReplacer(dict, replacer)
// {"foo":"BAR","hello":"WORLD","someNumber":42}

JSON.stringifyAny(() => "hello world")
// None

BigInt.fromInt(0)->JSON.stringifyAny
// exception

Exceptions

• Raises a TypeError if the value contains circular references.

• Raises a TypeError if the value contains BigInts.

stringifyAnyWithReplacerAndIndent(json, replacer, indentation)

Converts any type to a JSON string. The output will be indented. The replacer describes how the value should be transformed. It is a function which receives a key and a value. Stringifying a function or undefined will return None. If the value contains circular references or BigInts, the function will throw a JavaScript exception (TypeError). If you want to stringify a JSON object, use JSON.stringifyWithReplacerAndIndent instead.

Examples

RESCRIPT
let dict = Dict.fromArray([
  ("foo", JSON.Encode.string("bar")),
  ("hello", JSON.Encode.string("world")),
  ("someNumber", JSON.Encode.int(42)),
])

let replacer = (key, value) => {
  let decodedValue = value->JSON.Decode.string

  switch decodedValue {
  | Some(string) => string->String.toUpperCase->JSON.Encode.string
  | None => value
  }
}

JSON.stringifyAnyWithReplacerAndIndent(dict, replacer, 2)
// {
//   "foo": "BAR",
//   "hello": "WORLD",
//   "someNumber": 42
// }

JSON.stringifyAny(() => "hello world")
// None

BigInt.fromInt(0)->JSON.stringifyAny
// exception

Exceptions

• Raises a TypeError if the value contains circular references.

• Raises a TypeError if the value contains BigInts.

stringifyAnyWithFilter(json, filter)

Converts any type to a JSON string. The filter is an array of keys, which should be included in the output. Stringifying a function or undefined will return None. If the value contains circular references or BigInts, the function will throw a JavaScript exception (TypeError). If you want to stringify a JSON object, use JSON.stringifyWithFilter instead.

Examples

RESCRIPT
let dict = Dict.fromArray([
  ("foo", JSON.Encode.string("bar")),
  ("hello", JSON.Encode.string("world")),
  ("someNumber", JSON.Encode.int(42)),
])

JSON.stringifyAnyWithFilter(dict, ["foo", "someNumber"])
// {"foo": "bar","someNumber": 42}

JSON.stringifyAny(() => "hello world")
// None

BigInt.fromInt(0)->JSON.stringifyAny
// exception

Exceptions

• Raises a TypeError if the value contains circular references.

• Raises a TypeError if the value contains BigInts.

stringifyAnyWithFilterAndIndent(json, filter, indentation)

Converts any type to a JSON string. The output will be indented. The filter is an array of keys, which should be included in the output. Stringifying a function or undefined will return None. If the value contains circular references or BigInts, the function will throw a JavaScript exception (TypeError). If you want to stringify a JSON object, use JSON.stringifyWithFilterAndIndent instead.

Examples

RESCRIPT
let dict = Dict.fromArray([
  ("foo", JSON.Encode.string("bar")),
  ("hello", JSON.Encode.string("world")),
  ("someNumber", JSON.Encode.int(42)),
])

JSON.stringifyAnyWithFilterAndIndent(dict, ["foo", "someNumber"], 2)
// {
//   "foo": "bar",
//   "someNumber": 42
// }

JSON.stringifyAny(() => "hello world")
// None

BigInt.fromInt(0)->JSON.stringifyAny
// exception

Exceptions

• Raises a TypeError if the value contains circular references.

• Raises a TypeError if the value contains BigInts.