// ============================================================================
// 007 — Null Handling
// ============================================================================
// () is null in Soma. The ?? operator provides defaults for null values.
//
// Run:   soma run 007_null_handling.cell run
// Expect:
//   value is null: true
//   with default: 42
//   name: Unknown
//   found: Alice

cell NullHandling {

    on run() {
        // () is the null / unit value
        let value = ()

        // Check for null with == ()
        if value == () {
            print("value is null: true")
        }

        // ?? is the null-coalescing operator: returns left if non-null, else right
        let result = value ?? 42
        print("with default: {result}")

        // Practical example: missing map field returns ()
        let user = map("age", 25)
        let name = user.name ?? "Unknown"
        print("name: {name}")

        // When value exists, ?? returns the original value
        let user2 = map("name", "Alice", "age", 30)
        let name2 = user2.name ?? "Unknown"
        print("found: {name2}")

        return "done"
    }
}