12_json.nula

// 12_json.nula - JSON parsing and serialization
// Demonstrates: import stdlib::json, parse, stringify, field access,
//               round-trip fidelity with get_string and get_number
//
// Run: nulang examples/12_json.nula

import stdlib::json

// Parse a JSON string into a JsonValue
let input = """
{
  "name": "Nulang",
  "version": 1,
  "tags": ["fast", "safe", "expressive"],
  "nested": { "key": "value" }
}
"""
let parsed = parse(input)
perform IO.print("Parsed JSON successfully")

// Inspect parsed fields using get_string and get_number
let name = get_string(parsed, "name", "unknown")
perform IO.print("name = " + name)

let version = get_number(parsed, "version", -1.0)
perform IO.print("version = " + perform Float.to_string(version))

// Round-trip: parse → stringify → parse again
let json_str = stringify(parsed)
let reparsed = parse(json_str)
let name2 = get_string(reparsed, "name", "unknown")
perform IO.print("Round-trip name = " + name2)

// Parsing a JSON array
let arr_input = "[10, 20, 30, 40]"
let arr = parse(arr_input)
let arr_str = stringify(arr)
perform IO.print("Array round-trip: " + arr_str)

// Parsing boolean and null values
let values = parse("[true, false, null]")
let values_str = stringify(values)
perform IO.print("Bool/null round-trip: " + values_str)

// Parse a nested object and access nested field
let nested = parse("{\"outer\": {\"inner\": 42}}")
let outer_str = stringify(nested)
perform IO.print("Nested: " + outer_str)

perform IO.print("All JSON round-trips successful!")