This commit allows patterns like:
alt x { some(_) { ... } none { } }
without the '.' after none. The parser suspends judgment about
whether a bare ident is a tag or a new bound variable; instead,
the resolver disambiguates.
This means that any code after resolution that pattern-matches on
patterns needs to call pat_util::normalize_pat, which consults
an environment to do this disambiguation.
In addition, local variables are no longer allowed to shadow
tag names, so this required changing some code (e.g. renaming
variables named "mut", and renaming ast::sub to subtract).
The parser currently accepts patterns with and without the '.'.
Once the compiler and libraries are changed, it will no longer
accept the '.'.
The (temporary) syntax is
iface seq<T> {
fn len() -> uint;
fn iter(f: block(T));
}
// The 'blah<T>' can be left of to default the name of the
// impl to seq<T>. The 'of seq<T>' can be left off when
// not implementing a named interface.
impl blah<T> of seq<T> for [T] {
fn len() -> uint { vec::len(self) }
fn iter(f: block(T)) { for x in self { f(x); } }
}
This involved adding 'copy' to more generics than I hoped, but an
experiment with making it implicit showed that that way lies madness --
unless enforced, you will not remember to mark functions that don't
copy as not requiring copyable kind.
Issue #1177
You almost never want a function with pinned type params. For
types, objects, resources, and tags, pinned types are actually often
more sane. For most of these, shared rarely makes sense. Only tricky
case is objs -- you'll have to think about the kinds you want there.
Issue #1076
src/comp/syntax is currently just a sub-module of rustc, but it will,
in the near future, be its own crate. This includes:
- The AST data structure
- The parser
- The pretty-printer
- Visit, walk, and fold
- The syntax extension system
- Some utility stuff that should be in the stdlib*
*) Stdlib extensions currently require a snapshot before they can be
used, and the win build is very broken right now. This is temporary
and will be cleaned up when one of those problems goes away.
A lot of code was moved by this patch, mostly towards a more organized
layout. Some package paths did get longer, and I guess the new layout
will take some getting used to. Sorry about that!
Please try not to re-introduce any dependencies in syntax/ on any of
the other src/comp/ subdirs.
It would be better to either convert ast_map to use smallintmap or make
smallintmap and hashmap follow the same interface, but I don't feel up to
it just now. Closes#585.
