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[ghc-hetmet.git] / compiler / coreSyn / CoreSyn.lhs

diff --git a/compiler/coreSyn/CoreSyn.lhs b/compiler/coreSyn/CoreSyn.lhs
index b7a859f..e09e4f2 100644 (file)
--- a/compiler/coreSyn/CoreSyn.lhs
+++ b/compiler/coreSyn/CoreSyn.lhs
@@ -26,7 +26,7 @@ module CoreSyn (
        mkConApp, mkTyBind,
        varToCoreExpr, varsToCoreExprs,
 
-        isTyVar, isId, cmpAltCon, cmpAlt, ltAlt,
+        isTyCoVar, isId, cmpAltCon, cmpAlt, ltAlt,
        
        -- ** Simple 'Expr' access functions and predicates
        bindersOf, bindersOfBinds, rhssOfBind, rhssOfAlts, 
@@ -87,7 +87,7 @@ import Util
 import Data.Data
 import Data.Word
 
-infixl 4 `mkApps`, `mkTyApps`, `mkVarApps`
+infixl 4 `mkApps`, `mkTyApps`, `mkVarApps`, `App`
 -- Left associative, so that we can say (f `mkTyApps` xs `mkVarApps` ys)
 \end{code}
 
@@ -100,8 +100,6 @@ infixl 4 `mkApps`, `mkTyApps`, `mkVarApps`
 These data types are the heart of the compiler
 
 \begin{code}
-infixl 8 `App` -- App brackets to the left
-
 -- | This is the data type that represents GHCs core intermediate language. Currently
 -- GHC uses System FC <http://research.microsoft.com/~simonpj/papers/ext-f/> for this purpose,
 -- which is closely related to the simpler and better known System F <http://en.wikipedia.org/wiki/System_F>.
@@ -538,8 +536,11 @@ The instance translates to
 Now we might encounter (op (dfCList {ty} d) a1 a2)
 and we want the (op (dfList {ty} d)) rule to fire, because $dfCList
 has all its arguments, even though its (value) arity is 2.  That's
-why we cache the number of expected 
+why we record the number of expected arguments in the DFunUnfolding.
 
+Note that although it's an Arity, it's most convenient for it to give
+the *total* number of arguments, both type and value.  See the use
+site in exprIsConApp_maybe.
 
 \begin{code}
 -- Constants for the UnfWhen constructor
@@ -975,7 +976,7 @@ collectTyAndValBinders expr
 collectTyBinders expr
   = go [] expr
   where
-    go tvs (Lam b e) | isTyVar b = go (b:tvs) e
+    go tvs (Lam b e) | isTyCoVar b = go (b:tvs) e
     go tvs e                    = (reverse tvs, e)
 
 collectValBinders expr