The std/json module provides a complete JSON parser and builder. JSON values are represented as tagged Array nodes — the first element is the type tag and the second is the value — making it easy to inspect and traverse any JSON document.
// JSON con std/json: construir objetos, arrays y serializar/parsear números import "std/json" fn main() -> int { // Construir un objeto JSON programáticamente let keys: Array = ["name", "age", "activo"] let vals: Array = [] vals.push(json_string("Alice")) vals.push(json_number(30)) vals.push(json_bool(true)) let obj: Array = json_object(keys, vals) let serializado: String = json_stringify(obj) print("Objeto: " + serializado) // Construir un array JSON let items: Array = [] items.push(json_number(10)) items.push(json_number(20)) items.push(json_number(30)) let arr: Array = json_array(items) print("Array: " + json_stringify(arr)) // Parsear un número let parsed: Array = json_parse("42") print("Tipo: " + json_type(parsed)) let val: int = parsed[1] print("Valor: " + int_to_string(val)) // Parsear un array de números let parsed2: Array = json_parse("[1,2,3]") print("Array parseado: " + json_stringify(parsed2)) return 0 }
Objeto: {"name":"Alice","age":30,"activo":true}
Array: [10,20,30]
Tipo: number
Valor: 42
Array parseado: [1,2,3]How it works
JSON values are constructed with typed builder functions: json_string, json_number, json_bool, json_object, and json_array. Each returns a tagged Array where node[0] is the type string (e.g. "number") and node[1] is the payload. This uniform representation makes recursive traversal straightforward.
json_stringify serializes any JSON node back to a compact string. json_parse does the reverse — it accepts a JSON string and returns the same tagged-array structure, which you can then inspect with json_type or index directly.
For reading nested fields, you would chain array indexing: obj[1][1] reaches the first value in a JSON object node. The next example (16) focuses on building complex nested structures for serialization.