(The old syntax is still supported as well, for now.)
It is now possible to leave out the parens around if, while, and
do/while conditions, and around alt expressions. Cases in an alt block
can now leave off the case keyword and parens around the pattern.
After the next snapshot, we can start migrating our code to use the
new alt syntax, probably with a pretty-printer pass. The paren-free
syntax will remain optional (you may always parenthesize expressions),
but the old case syntax will no longer be supported in the future.
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.
