It is now no longer needed to have a ty::ctxt to get at the contents
of a ty::t. The straight-forward approach of doing this, simply making
ty::t a box type, unfortunately killed our compiler performance (~15%
slower) through refcounting cost. Thus, this patch now represents
ty::t as an unsafe pointer, assuming that the ty::ctxt, which holds
these boxes alive, outlives any uses of the ty::t values. In the
current compiler this trivially holds, but it is does of course add a
new potential pitfall.
ty::get takes a ty::t and returns a boxed representation of the type.
I've changed calls to ty::struct(X) to do ty::get(X).struct. Type
structs are full of vectors, and copying them every time we wanted to
access them was a bit of a cost.
Now that core exports "option" as a synonym for option::t, search-and-
replace option::t with option.
The only place that still refers to option::t are the modules in libcore
that use option, because fixing this requires a new snapshot
(forthcoming).
This simplifies the typechecker a bit (no more ty_param_substs_opt_and_ty)
and is needed for another experiment I'm playing with. I hope it also
makes compilation faster (the bots will tell).
Rather, it is now a struct where properties like opts are accessed
directly, and the error-reporting methods are part of a static impl
(with the same name as the type).
Get rid of expr_self_call, introduces def_self. `self` is now,
syntactically, simply a variable. A method implicitly brings a `self`
binding into scope.
Issue #1227
This makes it possible to omit the semicolon after the block, and will
cause the pretty-printer to properly print such calls (if
pretty-printing of blocks wasn't so broken). Block calls (with the
block outside of the parentheses) can now only occur at statement
level, and their value can not be used. When calling a block-style
function that returns a useful value, the block must be put insde the
parentheses.
Issue #1054
We were only using it in a single place, and there for no discernable reason
(probably as part of the bare-fn-vals-are-not-copyable plan). It seems more
surprising than useful.
Arguments that can't be safely referenced will be implicitly copied.
(Warnings for expensive copies will be forthcoming.)
This will allow us to get rid of most of the ampersands in function
signatures. See [1].
[1] https://mail.mozilla.org/pipermail/rust-dev/2011-September/000759.html
Upvars are now marked with def_upvar throughout, not just when going
through freevars::lookup_def. This makes things less error-prone. One
thing to watch out for is that def_upvar is used in `for each` bodies
too, when they refer to a local outside the body.
Having it in the alias pass was slightly more efficient (finding
expression roots has to be done in both passes), but further muddled
up the already complex alias checker.
Also factors out some duplication in the mutability-checking code.
