Commit Graph
7 Commits
Author SHA1 Message Date
josh11bandRichard Smith c08cbdb0bd Clarify class declaration syntax (#1026)
Clarify class declaration syntax

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2022-01-14 14:23:43 -08:00
josh11bandRichard Smith 1534970146 Implicit conversions for aggregates (#981)
Define initialization, assignment, comparison, and implicit conversion between data classes with different field orders and/or types.

Implements the decision made in #710 .

Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2022-01-06 11:16:41 -08:00
Jon Meowandjosh11b 24b763c7e8 Fix or remove invalid anchor links, adding pre-commit (#997)
Co-authored-by: josh11b <josh11b@users.noreply.github.com>
2022-01-05 15:00:02 -08:00
josh11b cfb36b85e5 Merge overview sections (#899) 2021-10-19 11:58:48 -07:00
3610325c38 Inheritance (#777)
This proposal adds inheritance to classes, following this syntax:
```
// Abstract classes may not be instantiated, but
// may have abstract methods and be extended.
abstract class AbstractBaseClass {
  virtual fn CanBeOverridden[me: Self]() -> i32 {
    return me.data;
  }
  abstract fn PureVirtual[me: Self]() -> i32;
  fn Create(data: i32) -> partial Self {
    return {.data = data};
  }
  protected var data: i32;
}

// Classes are final by default
class FinalClass extends AbstractBaseClass {
  impl fn PureVirtual[me: Self]() -> i32 {
    return me.x;
  }
  fn Create(data: i32) -> Self {
    return {.base = AbstractBaseClass.Create(data), .x = 2 * data};
  }
  private var x: i32;
}

// Can be instantiated and extended
base class ExtensibleClass {
  // May optionally use partial types in factory functions
  protected fn CreateAsBase(data: i32) -> partial Self { ... }
  fn Create(data: i32) -> Self { ... }
}
```

Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
2021-09-08 17:37:35 -07:00
josh11bandChandler Carruth 0820dec01f Nominal classes and methods (#722)
Add support for nominal (or "named") classes with encapsulation. Inheritance will be in a later proposal. Here is an example of the proposed syntax:

```
class Circle {
  fn Create(c: Point, r: f32) -> Self {
    return {.center = c, .radius = r};
  }
  fn Diameter[me: Self]() -> f32 {
    return me.radius * 2;
  }
  fn Expand[addr me: Self*](distance: f32);

  private var center: Point;
  private var radius: f32;
}

fn Circle.Expand[addr me: Self*](distance: f32) {
  me->radius += distance;
}
```

Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
2021-08-23 15:45:41 -07:00
36764ff1af Basic classes: use cases, struct literals, struct types, and future work (#561)
This proposal defines the very basics of `class` types, primarily focused on:

-   use cases including: data classes, encapsulated types, inheritance with and without `virtual`, interfaces as base classes, and mixins for code reuse;
-   anonymous data types for called _structural data classes_ or _struct types_. Struct literals are used to initialize class values and ad-hoc parameter and return types with named components; and
-   future work, including the provisional syntax already in use for features that have not been decided.

The intent is to both make some small incremental progress and get agreement on direction. As such it doesn't include things like nominal types, methods, access control, inheritance, etc.

It proposes this struct type and literal syntax:
```
var p: {.x: Int, .y: Int} = {.x = 0, .y = 1};
```
Note that it uses commas (`,`) between fields instead of semicolons (`;`), and no introducer for types or literal values.

Incorporates decisions from #665 , #653 , #651


Co-authored-by: Geoff Romer <gromer@google.com>
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
2021-08-09 12:28:36 -07:00