//! Module-owned record representations and their public operations.

/// Number accessed through module operations.
export opaque record Value: Copy {
    /// Stored number.
    number: u32,
}

/// Positional number wrapper.
export opaque record Word: Copy(u32);

/// Number borrowed for a region.
export opaque record View: 'r + Copy {
    /// Borrowed number.
    number: &'r u32,
}

/// Construct a number.
export fn create(number: u32) -> Value {
    return { number };
}

/// Read the stored number.
export fn (self: &Value) read() -> u32 {
    return self.number;
}

/// Add to the stored number.
export fn (self: &mut Value) add(amount: u32) {
    set self.number += amount;
}

/// Read a number through a record pattern.
export fn unpack(value: Value) -> u32 {
    let case Value { number } = value else panic;
    return number;
}

/// Construct a positional wrapper.
export fn word(number: u32) -> Word {
    return Word(number);
}

/// Read a positional wrapper.
export fn readWord(value: Word) -> u32 {
    return *value;
}

/// Wrap a regional borrow.
export fn view 'r (number: &'r u32) -> View 'r {
    return View 'r { number };
}

/// Read a regional wrapper.
export fn readView 'r (value: &View 'r) -> u32 {
    return *value.number;
}