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 '.'.
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).
Now, if you have a tag named "foo", a variable declaration like
"let foo..." is illegal. This change makes it possible to eliminate
the '.' after a nullary tag pattern in an alt (but I'll be doing
that in a future commit) -- as now it's always obvious whether a
name refers to a tag or a new declared variable.
resolve implements this change -- all the other changes are just to
get rid of existing code that declares variables that shadow tag
names.
Aligning the type parameters of the ifaces, impls, and methods
correctly in typeck is almost brain surgery. Seems to work now for
everything I threw at it, but might still break in other corner cases.
Issue #1227
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); } }
}
Issue #828
This is not a full solution yet. To really get sane error messages,
we'll also have to guess the name to apply to literals, which seems
non-trivial.
Something will still have to be done to the AST to make it possible to
say `x.foo::<int>()`, since currently field access never allows type
parameters.
Issue #1227
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
