* Cleans up the algorithm
* Move first pass to walk (second still folds)
* Support part of a type/value namespace split
(crate metadata and module indices still need to be taught about this)
* Remove a few blatant inefficiencies (import tables being recreated for
every lookup, most importantly)
Check that the operand in a constraint is an explicit name,
and that the operands are all local variables or literals. Still need
to check that the name refers to a pure function.
Added support for self_method, cont, chan, port, recv, send, be,
do_while, spawn, and ext; handled break and cont correctly.
(However, there are no non-xfailed test cases for ext or spawn in
stage0 currently.)
Although the standard library compiles and all test cases pass with
typestate enabled, I left typestate checking disabled as rustc
terminates abnormally when building the standard library if so,
even though it does generate code correctly.
Summary says it all. Actually, only nested objects and functions
are handled, but that's better than before. The fold that I was using
before to traverse a crate wasn't working correctly, because annotations
have to reflect the number of local variables of the nearest enclosing
function (in turn, because annotations are represented as bit vectors).
The fold was traversing the AST in the wrong order, first filling in
the annotations correctly, but then re-traversing them with the bit
vector length for any outer nested functions, and so on.
Remedying this required writing a lot of tedious boilerplate code
because I scrapped the idea of using a fold altogether.
I also made typestate_check handle unary, field, alt, and fail.
Also, some miscellaneous changes:
* added annotations to blocks in typeck
* fix pprust so it can handle spawn
* added more logging functions in util.common
* fixed _vec.or
* added maybe and from_maybe in option
* removed fold_block field from ast_fold, since it was never used
module, we should look for 'b' *just* in the module 'a' and then continue
resolving b.c in the environment created by updating *with* a.
Still not 100% correct, but getting there.
* If an import was unused we would never print any errors for it.
* We would keep the existing environment in scope when descending 'foo.bar'
and would find 'bar' in the global environment if there was no 'bar' in
'foo'.
ast.ml - modified arm types for easier polymorphism
- fixed a bug in fmt_type_arm
dead.ml - modified arm types for easier polymorphism
common.ml - added 'either'
- added some useful auxiliary functions
item.ml - modified arm code to be more polymorphic and handle both alt-tag and alt-type, also fixed the problematic case in bad-alt.rs
Makefile - added XFAIL for new alt-type test
bad-alt.rs - added test for invalid alt syntax
alt-type-simple.rs - added simple test for alt type
