gleam/json
Types
pub type DecodeError {
UnexpectedEndOfInput
UnexpectedByte(byte: String, position: Int)
UnexpectedSequence(byte: String, position: Int)
}
Constructors
-
UnexpectedEndOfInput
-
UnexpectedByte(byte: String, position: Int)
-
UnexpectedSequence(byte: String, position: Int)
Functions
pub fn array(
from entries: List(a),
of inner_type: fn(a) -> Json,
) -> Json
Encode a list into a JSON array.
Examples
> to_string(array([1, 2, 3], of: int))
"[1, 2, 3]"
pub external fn bool(input: Bool) -> Json
Encode a bool into JSON.
Examples
> to_string(bool(False))
"false"
pub external fn decode(String) -> Result(Dynamic, DecodeError)
Decode a JSON string into dynamically typed data which can be decoded into
typed data with the gleam/dynamic
module.
Examples
> decode("[1,2,3]")
Ok(dynamic.from([1, 2, 3]))
> decode("[")
Error(UnexpectedEndOfInput)
pub external fn float(input: Float) -> Json
Encode an float into JSON.
Examples
> to_string(float(4.7))
"4.7"
pub external fn int(input: Int) -> Json
Encode an int into JSON.
Examples
> to_string(int(50))
"50"
pub fn nullable(
from input: Option(a),
of inner_type: fn(a) -> Json,
) -> Json
Encode an optional value into JSON, using null if it the None
variant.
Examples
> to_string(nullable(Some(50), of: int))
"50"
> to_string(nullable(None, of: int))
"null"
pub external fn object(entries: List(#(String, Json))) -> Json
Encode a list of key-value pairs into a JSON object.
Examples
> to_string(object([
#("game", string("Pac-Man")),
#("score", int(3333360)),
]))
"{\"game\":\"Pac-Mac\",\"score\":3333360}"
pub external fn preprocessed_array(from: List(Json)) -> Json
Encode a list of JSON values into a JSON array.
Examples
> to_string(preprocessed_array([int(1), float(2.0), string("3")]))
"[1, 2.0, \"3\"]"
pub external fn string(input: String) -> Json
Encode a string into JSON, using normal JSON escaping.
Examples
> to_string("Hello!")
"\"Hello!\""
pub external fn to_string(Json) -> String
Convert a JSON value into a string.
Where possible prefer the to_string_builder
function as it is faster than
this function, and BEAM VM IO is optimised for sending StringBuilder
data.
Examples
> to_string(array([1, 2, 3], of: int))
"[1,2,3]"
pub external fn to_string_builder(Json) -> StringBuilder
Convert a JSON value into a string builder.
Where possible prefer this function to the to_string
function as it is
slower than this function, and BEAM VM IO is optimised for sending
StringBuilder
data.
Examples
> to_string_builder(array([1, 2, 3], of: int))
string_builder.from_string("[1,2,3]")