From e6162877af8246d727850b3e04d4ab23d72cfe5f Mon Sep 17 00:00:00 2001
From: Neil Brown <neil@twistedsquare.com>
Date: Sat, 17 May 2008 12:47:31 +0000
Subject: [PATCH] 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 | 16 ++++++++++++----
 data/AST.hs        |  7 +++++--
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/common/ShowCode.hs b/common/ShowCode.hs
index c3031db..ece5726 100644
--- a/common/ShowCode.hs
+++ b/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
diff --git a/data/AST.hs b/data/AST.hs
index 4989d1e..8210380 100644
--- a/data/AST.hs
+++ b/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.