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.
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); } }
}
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
See src/test/run-pass/nested-patterns.rs for some examples. The syntax is
boundvar@subpattern
Which will match the subpattern as usual, but also bind boundvar to the
whole matched value.
Closes#838
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
