05_records.nula

// 05_records.nula - Records and nested data
// Demonstrates: record construction, field access, nested records,
//               record mutation, and functions over records
//
// Run: nulang examples/05_records.nula

// Record construction and field access
let point = { x: 3, y: 4 }
perform IO.print("point.x = " + perform Int.to_string(point.x))
perform IO.print("point.y = " + perform Int.to_string(point.y))

// Computed from fields
let dist = point.x + point.y
perform IO.print("dist = " + perform Int.to_string(dist))

// Record field mutation
let counter = { value: 0 }
counter.value = counter.value + 10
perform IO.print("counter = " + perform Int.to_string(counter.value))

// Nested records
let rect = { pos: { x: 10, y: 20 }, w: 30, h: 40 }
perform IO.print("rect.pos.x = " + perform Int.to_string(rect.pos.x))
perform IO.print("rect.w = " + perform Int.to_string(rect.w))
perform IO.print("rect.h = " + perform Int.to_string(rect.h))

// Nested mutation
rect.pos.x = 100
perform IO.print("rect.pos.x after mutation = " + perform Int.to_string(rect.pos.x))

// Function returning a record
let make_person = fn(name, age) {
    { name: name, age: age }
}
let alice = make_person("Alice", 30)
perform IO.print(alice.name + " is " + perform Int.to_string(alice.age))

// Record as function parameter
let describe = fn(person) {
    person.name + ", age " + perform Int.to_string(person.age)
}
perform IO.print(describe(alice))