Standalone anonymous records

Without a nominal target, .{ fields } infers an anonymous record with exact field types and ordinary field access. An exact expected struct still selects contextual nominal construction. An invalid supplied target is diagnosed instead of being silently replaced by a structural type.

Complete example

// Anonymous records keep the exact type of each field.

// A nominal annotation still selects that type's ordinary constructor.

fn main() {
    let count = 3
    let summary = .{ count, total: 12 }
    let next = summary with { total: 15 }
    print(summary.count, summary.total)
    print(next.total)
    // expected: 3 12

    // expected: 15

}
main()

Rules and behavior

Records, maps and updates · Documentation

From a checkout of the repository:

zolo examples/features/06-data-structures/24-anonymous-records.zolo