This is not my ideal way of going about things. I'd prefer not
to have expressions typed as fn*(), for example, but I couldn't
get that to work together with inferring the modes of arguments
and other corner cases.
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 '.'.
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.
Before, literal printing would basically get derailed completely when
a literal was encountered that did not end up being printed. This
caused the strangeness seen in #1532.
Also cleans up pretty-printing of discriminants a little.
Closes#1510Closes#1532
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).
Use ifaces instead of objs, stop wrapping everything in two (or three)
layers of no-value-added indirection, and remove some of the more
pointless/outdated idioms from the code.
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.
