JSON

Parse and generate JSON data. Supports both single JSON documents and JSONL (JSON Lines) format.

import Encoding.JSON

Parsing

JSON.parse

String -> Result JSONValue Error

Parse a JSON string into a JSONValue. Returns an error for invalid JSON.

json-str = '{"name": "Kit", "version": 1}'
match JSON.parse json-str
  | Ok value -> println "Parsed successfully"
  | Err e -> println "Parse error: ${e}"

JSON.to-json

a -> JSONValue

Convert any Kit value to a JSONValue. Works with records, lists, strings, numbers, and booleans.

record = {name: "Kit", version: 1}
json-value = JSON.to-json record

Stringification

JSON.stringify

JSONValue -> String

Convert a JSONValue to a compact JSON string (single line, no extra whitespace).

json = JSON.to-json {name: "Kit", version: 1}
str = JSON.stringify json
# {"name":"Kit","version":1}

JSON.pretty

JSONValue -> String

Pretty-print a JSONValue with indentation and line breaks for readability.

json = JSON.to-json {name: "Kit", tags: ["functional", "typed"]}
println (JSON.pretty json)
# {
#   "name": "Kit",
#   "tags": [
#     "functional",
#     "typed"
#   ]
# }

JSONL Support

JSONL (JSON Lines) is a format where each line is a valid JSON document. Useful for streaming and log processing.

JSON.parse-lines

String -> Result [JSONValue] Error

Parse a JSONL string into a list of JSONValues, one per line.

jsonl = "{\"id\": 1}\n{\"id\": 2}\n{\"id\": 3}"
match JSON.parse-lines jsonl
  | Ok items -> println "Parsed ${List.length items} records"
  | Err e -> println "Error: ${e}"

JSON.stringify-lines

[JSONValue] -> String

Convert a list of JSONValues to a JSONL string (one JSON document per line).

items = [
  JSON.to-json {id: 1, name: "Alice"},
  JSON.to-json {id: 2, name: "Bob"}
]
jsonl = JSON.stringify-lines items
# {"id":1,"name":"Alice"}
# {"id":2,"name":"Bob"}