This makes sure that we catch all leftover instances of using SYB to do generic operations that we should be using Polyplate for instead. Most modules should only import Data, and possibly Typeable.
For now, I have fixed the occam parser so that it allows 1 or more direction specifiers after channel names. So c?? is valid, and should end up being equivalent to c?, but this may need altering later.
As part of this patch, I have also introduced a helper function that fiddles the type system for those passes that must run at the top-level (i.e. on A.AST) rather than on any Data t. They will give an error if not applied at the top-level.
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.
This changes the Traversal API to the one that I've been working on in
the Polyplate branch, but implemented in terms of Data. The
performance isn't as good as the Polyplate version, but the code is a
lot simpler because it doesn't need all the type constraints (and it
doesn't make GHC struggle).
This also reworks all the passes in Tock to use the new API, including
those that previously used makeGeneric (which I've now removed) or
everywhereM. Most of the passes are simpler because of this, and I
suspect it's fixed a few subtle bugs resulting from missing recursion
in makeGeneric code.
I haven't yet profiled this, but subjectively it seems about the same
as the old Traversal (and thus faster for all the passes that didn't
yet use it).
Function returns are done in Rain by assigning to the function name, so we need a bit of extra code when checking assignments to see if the LHS is a function name.
The new behaviour is to check that both sides of a dyadic operator have the same type. This means that multiplying time by a scalar is no longer possible, but it also means (due to the lack of checks after unification) that multiplying two lists is possible, or concatenating two integers. This needs to be fixed by adding another pass.
Instead of storing the Constr, which was messy, we now store a String (to allow comparison of constructor types during unification) and a function to reform the type at the end of the type checking.
This patch hides all the old typeOfExpression, typeOfName, typeOfVariable, etc, and unifies them into a single type-class with an "astTypeOf" function. The type-class is currently named Typed, but that can easily be changed (it's only explicitly referred to in the Types module). The patch is essentially the type-class with a giant find-and-replace on the other modules.
We now have three kinds of canned tree traversals, all of which are smart about
which types they're applied to: explicit-descent transformations,
implicit-descent transformations, and implicit-descent checks. I've only
provided depth-first application of the latter two, but we could do
breadth-first in the future if necessary.
It's redundant, since you can always compute them from the variable, and it
makes the code that deals with actuals rather cleaner.
On the other hand, it slightly complicates some of the tests, because any names
you use in an Actual need to be defined...
