lux/examples/json.lux

// JSON example - demonstrates JSON parsing and manipulation
//
// This script parses JSON, extracts values, and builds new JSON structures

fn main(): Unit with {Console, File} = {
    Console.print("=== Lux JSON Example ===")
    Console.print("")

    // First, build some JSON programmatically
    Console.print("=== Building JSON ===")
    Console.print("")

    let name = Json.string("Alice")
    let age = Json.int(30)
    let active = Json.bool(true)
    let scores = Json.array([Json.int(95), Json.int(87), Json.int(92)])

    let person = Json.object([("name", name), ("age", age), ("active", active), ("scores", scores)])

    Console.print("Built JSON:")
    let pretty = Json.prettyPrint(person)
    Console.print(pretty)
    Console.print("")

    // Stringify to a compact string
    let jsonStr = Json.stringify(person)
    Console.print("Compact: " + jsonStr)
    Console.print("")

    // Write to file and read back to test parsing
    File.write("/tmp/test.json", jsonStr)
    Console.print("Written to /tmp/test.json")
    Console.print("")

    // Read and parse from file
    Console.print("=== Parsing JSON ===")
    Console.print("")
    let content = File.read("/tmp/test.json")
    Console.print("Read from file: " + content)
    Console.print("")

    match Json.parse(content) {
        Ok(json) => {
            Console.print("Parse succeeded!")
            Console.print("")

            // Get string field
            Console.print("Extracting fields:")
            match Json.get(json, "name") {
                Some(nameJson) => match Json.asString(nameJson) {
                    Some(n) => Console.print("  name: " + n),
                    None => Console.print("  name: (not a string)")
                },
                None => Console.print("  name: (not found)")
            }

            // Get int field
            match Json.get(json, "age") {
                Some(ageJson) => match Json.asInt(ageJson) {
                    Some(a) => Console.print("  age: " + toString(a)),
                    None => Console.print("  age: (not an int)")
                },
                None => Console.print("  age: (not found)")
            }

            // Get bool field
            match Json.get(json, "active") {
                Some(activeJson) => match Json.asBool(activeJson) {
                    Some(a) => Console.print("  active: " + toString(a)),
                    None => Console.print("  active: (not a bool)")
                },
                None => Console.print("  active: (not found)")
            }

            // Get array field
            match Json.get(json, "scores") {
                Some(scoresJson) => match Json.asArray(scoresJson) {
                    Some(arr) => {
                        Console.print("  scores: " + toString(List.length(arr)) + " items")
                        // Get first score
                        match Json.getIndex(scoresJson, 0) {
                            Some(firstJson) => match Json.asInt(firstJson) {
                                Some(first) => Console.print("    first score: " + toString(first)),
                                None => Console.print("    first score: (not an int)")
                            },
                            None => Console.print("    (no first element)")
                        }
                    },
                    None => Console.print("  scores: (not an array)")
                },
                None => Console.print("  scores: (not found)")
            }
            Console.print("")

            // Get the keys
            Console.print("Object keys:")
            match Json.keys(json) {
                Some(ks) => Console.print("  " + String.join(ks, ", ")),
                None => Console.print("  (not an object)")
            }
        },
        Err(e) => Console.print("Parse error: " + e)
    }

    Console.print("")
    Console.print("=== JSON Null Check ===")
    let nullVal = Json.null()
    Console.print("Is null value null? " + toString(Json.isNull(nullVal)))
    Console.print("Is person null? " + toString(Json.isNull(person)))
}

let result = run main() with {}