Check that in export foo{}, foo is an enum type, and that in export
foo{bar, quux}, foo is an enum type and bar and quux are variants belonging
to foo.
See issue 1426 for details. Now, the semantics of "export t;" where t is a tag are
to export all of t's variants as well. "export t{};" exports t but not its
variants, while "export t{a, b, c};" exports only variants a, b, c of t.
To do:
- documentation
- there's currently no checking that a, b, c are actually variants of t in the
above example
- there's also no checking that t is an enum type, in the second two examples above
- change the modules listed in issue 1426 that should have the old export
semantics to use the t{} syntax
I deleted the test export-no-tag-variants since we're doing the opposite now,
and other tests cover the same behavior.
Support Lenny222's proposed syntax for exporting a tag without
its variants, or selected tags from a variant, in the AST and parser.
No support further down the line yet. Tests are xfailed.
Previously, typestate would conclude that this function was
correctly diverging:
fn f() -> ! { ret; fail; }
even though it always returns to the caller. It wasn't handling the
i_diverge and i_return bits correctly in the fail case. Fixed it.
Closes#897
Remove disr_val from ast::variant_ and always use ty::variant_info
when the value is needed. Move what was done during parsing into
other passes, primary typeck.rs. This move also correctly type checks
the disr. value expression; thus, fixing rustc --pretty=typed when
disr. values are used.
Addresses issue #1393.
For now disallow disr. values unless all variants use nullary
contractors (i.e. "enum-like").
Disr. values are now encoded in the crate metadata, but only when it
will differ from the inferred value based on the order.
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.
