Changed the AST to fix the different unknown/inferred types

The Infer type (used by the occam frontend) is now separated from the "Unknown" types used in type unification that I'm experimenting with in Rain.

common/ShowCode.hs

@@ -225,8 +225,12 @@ instance ShowOccam A.Type where
   showOccamM A.Any = tell ["ANY"]
   showOccamM (A.Timer _) = tell ["TIMER"]
   showOccamM A.Time = tell ["TIME"]
-  showOccamM A.Infer = tell ["(inferred type)"]
-  showOccamM (A.InferNum n) = tell ["(inferred numeric type: ",show n,")"]
+  showOccamM (A.UnknownVarType en)
+    = do tell ["(inferred type for: "]
+         either showName (const $ return ()) en
+         tell [")"]
+  showOccamM (A.UnknownNumLitType m _ n)
+    = tell ["(inferred numeric type: ",show m," ",show n,")"]
   showOccamM (A.Mobile t) = tell ["MOBILE "] >> showOccamM t
   showOccamM (A.Array ds t)
       = (sequence dims) >> showOccamM t
@@ -267,8 +271,12 @@ instance ShowRain A.Type where
   -- Mobility is not explicit in Rain:
   showRainM (A.Mobile t) = showRainM t
   showRainM (A.List t) = tell ["["] >> showRainM t >> tell ["]"]
-  showRainM A.Infer = tell ["(inferred type)"]
-  showRainM (A.InferNum n) = tell ["(inferred numeric type: ",show n,")"]
+  showRainM (A.UnknownVarType en)
+    = do tell ["(inferred type for: "]
+         either showName (const $ return ()) en
+         tell [")"]
+  showRainM (A.UnknownNumLitType m _ n)
+    = tell ["(inferred numeric type: ",show m," ",show n,")"]
   showRainM x = tell ["<invalid Rain type: ", show x, ">"]
 
 instance ShowOccam A.DyadicOp where

data/AST.hs

@@ -144,9 +144,12 @@ data Type =
   | Mobile Type
   -- | A type that will be inferred automatically by a pass.
   | Infer
+  -- | A type that will be inferred by type unification.  Either for a named
+  -- variable, or for an anonymous, uniquely identified, expression
+  | UnknownVarType (Either Name (Meta, Int))
   -- | A numeric type to be inferred later, that must be able to hold the given
-  -- value
-  | InferNum Integer
+  -- value.  The Int is a unique identifier, the Integer is the number to hold
+  | UnknownNumLitType Meta Int Integer
   deriving (Show, Eq, Typeable, Data)
 
 -- | An array dimension.