NameType is only really needed in the parser, so this takes it out of
NameDef, meaning that later passes defining names no longer need to
set an arbitrary NameType for them. The parser gets slightly more
complicated (because some productions now have to return a SpecType
and a NameType too), but lots of other code gets simpler.
The code that removed free names was the only thing outside the parser
using NameType, and it now makes a more sensible decision based on the
SpecType. Since unscoped names previously didn't have a SpecType at
all, I've added an Unscoped constructor to it and arranged matters
such that unscoped names now get a proper entry in csNames.
Fixes#61.
As part of this patch I also had to provide a Data instance for TypeExp (to allow CompState to still be an instance of Data). Using IORefs is easier than STRef RealWorld, and puts everything in terms of IO (which is already in PassM) rather than ST (which would require more lifting).
Previously they had a list of the types they needed to generate
instances for. This patch adds some helper code that can be used to
list all the AST.* types in the AST automatically. The result is that we
should be able to add new types to the AST without needing to change the
generator code.
This also means that GenOrdAST is now generating *all* the instances of
Ord for the AST; previously the trivial ones were derived by the
compiler.
The existing constant-folding code in the parser is still there, since it needs
to know whether things are constant, and A.Dimension expects an Int.
However, this pass is useful because it does a better job of constant folding
than the parser would on its own: it can fold subexpressions of expressions
that are as a whole not constant.
This implements #DEFINE, #UNDEF, #IF, #ELSE and #ENDIF, macro expansion with
##, and TRUE, FALSE, AND, OR, NOT and DEFINED within #IF expressions, with the
same semantics as occ21.
The macro COMPILER.TOCK is always defined by default, so you can now say things
like "#IF NOT DEFINED (COMPILER.TOCK) ... #ENDIF".
