This includes:
- Syntax changes from this chart:
| Before | After |
| ------------------------------- | --------------------------------------- |
| `class D extends B { ... }` | `class D { extend base: B; ... }` |
| `external impl C as Sub;` | `impl C as Sub;` |
| `class C { impl as Sortable; }` | `class C { extend impl as Sortable; }` |
| `adapter A for C { ... }` | `class A { adapt C; ... }` |
| `adapter A extends C { ... }` | `class A { extend adapt C; ... }` |
| `interface I { impl as J; }` | `interface I { require Self impls J; }` |
| `interface I { extends J; }` | `interface I { extend J; }` |
- Dropping the syntax for conditionally implemented internal interfaces.
This does not include:
- terminology changes from #2760 ("internal" and "external")
- changes to code, such as explorer, toolchain, language grammars, or other tooling
Use the keyword `impls` instead of `is` when writing a `where` constraint that a type variable needs to implement an interface or named constraint.
What was previously (provisionally) written:
```
fn Sort[T:! Container where .ElementType is Ordered](x: T*);
```
will now be written:
```
fn Sort[T:! Container where .ElementType impls Ordered](x: T*);
```
---------
Co-authored-by: Geoff Romer <gromer@google.com>
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Assignment is permitted only as a complete statement, not as a subexpression.
Assignment and compound assignment syntax follow C++ in all other respects.
Pre-increment is provided. Post-increment is not. Uses of all of these operators
are translated into calls to interface members.
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
josh11b
