All field or method references within a class must begin with "self." now.
A bare reference to a field or method in the same class will no longer
typecheck.
Allow writing self.f() within a class that has a method f. In a future
commit, this syntax will be required. For now, you can write either
self.f() or f().
I added a "privacy" field to all methods (whether class methods or not),
which allowed me to refactor the AST somewhat (getting rid of the
class_item type; now there's just class_member).
Allow writing self.f within a class that has a field f. Currently,
the compiler accepts either self.f or f. In a future commit I'll
require writing self.f and not f.
Not sure whether self.f() works if f is a method (making sure that
works next).
1. Enforce mutability declarations on class fields. Don't allow any
mutation of class fields not declared as mutable (except inside the
constructor).
2. Handle classes correctly in shape (treat classes like records).
The code is somewhat invasive, but it seems hard to do this in a
clean way, since the design itself involves a bunch of 'action
at a distance'.
Issue #1819
This change uses the same code for handling the "self" reference for
classes as is already used for impls/ifaces. This allows removing the
extra maybe_self_id argument (which was just for classes) to trans_closure
that I added before. I also rewrote the translation for class ctors so
that it doesn't generate new AST nodes (instead translating directly).
Also changed visit so that it visits class ctors correctly with visit_fn,
and changed typestate to not do return-checking when visiting a class ctor.
Cross-crate method calls don't work yet. Added
run-pass/class-method-cross-crate to test that, but it's xfailed
References to fields within methods don't work yet. Added
run-pass/class-methods to test that, but it's also xfailed
In particular, use the ast::method type to represent a class method,
and try to reuse as much iface code as possible. (This makes sense now
since I'll be allowing polymorphic class methods.)
Cross-crate metadata for classes works well enough that programs with
classes in other crates compile successfully, but output wrong results.
Checking in work so far to avoid merge hassles. (Tests are xfailed.)
