Also changed the ts_ann field on statements to be an ann instead,
which explains most of the changes.
As well, got rid of the "warning: no type for expression" error
by filling in annotations for local decls in typeck (not sure whether
this was my fault or not).
Finally, in bitv, added a clone() function to copy a bit vector,
and fixed is_true, is_false, and to_str to not be nonsense.
Nicer parsing of self-calls (expr_self_method nodes inside expr_call
nodes, rather than a separate expr_call_self) makes typechecking
tractable. We can now write self-calls that take arguments and return
values (see: test/run-pass/obj-self-*.rs).
It's still sketchy. I added a typestate annotation field to statements
tagged stmt_decl or stmt_expr, because a stmt_decl statement has a typestate
that's different from that of its child node. This necessitated trivial
changes to a bunch of other files all over to the compiler. I also added a
few small standard library functions, some of which I didn't actually end
up using but which I thought might be useful anyway.
Mostly:
* Merciless refactoring of trans.rs so that trans_call can work for
self-calls as well as other kinds of calls
Also:
* Various changes to go with having idents, rather than exprs, in
expr_call_self AST nodes
* Added missing case for SELF token to token.to_str()
I added a new field to the ast "ann" type for typestate information.
Currently, the field contains a record of a precondition bit vector and
postcondition vector, but I tried to structure things so as to make
it easy to change the representation of the typestate annotation type.
I also had to add annotations to some syntactic forms that didn't have
them before (fail, ret, be...), with all the boilerplate changes
that that would imply.
The main call to the typestate_check entry point is commented out and
the actual pre-postcondition algorithm only has a few cases
implemented, though the overall AST traversal is there. The rest of
the typestate algorithm isn't implemented yet.
