Change naming conventions for compiler-generated dictionaries and type functions

Up to now, the data constructor dictionary for class C as been called
":DC". But there is no reason for the colon to be at the front; indeed
it confuses the (simple-minded) pretty-printer for types.  So this
patch changes it to be "D:C".  This makes Core a lot easier to read.
Having a colon in the middle ensures that it can't clash with a user-written
data type.

Similarly I changed

  T:C 	   Data type corresponding a class dictionary (was :TC)
  D:C	   Data constructor for class dictionary (was :DC)

  NTCo:T   Coercion mapping from a newtype T to its representation type
		(was :CoT)

  TFCo:R   Coercion mapping from a data family to its respresentation type R
		(was :CoFR)

  Rn:T     The n'th respresentation data type for a data type T
		(was :RnT)

Do not merge to 6.10.

HEADS-UP: you'll need to recompile libraries from scratch.

ROMAN: you could do the same for OccName.mkVectTyConOcc etc, if you wanted.

diff --git a/compiler/basicTypes/OccName.lhs b/compiler/basicTypes/OccName.lhs
index a363c1c..c2aae5d 100644 (file)
--- a/compiler/basicTypes/OccName.lhs
+++ b/compiler/basicTypes/OccName.lhs
@@ -481,19 +481,24 @@ reportIfUnused occ = case occNameString occ of
 
 Here's our convention for splitting up the interface file name space:
 
-       d...            dictionary identifiers
-                       (local variables, so no name-clash worries)
+   d...                dictionary identifiers
+               (local variables, so no name-clash worries)
 
-       \$f...          dict-fun identifiers (from inst decls)
-       \$dm...         default methods
-       \$p...          superclass selectors
-       \$w...          workers
-       :T...           compiler-generated tycons for dictionaries
-       :D...           ...ditto data cons
-        :Co...          ...ditto coercions
-       \$sf..          specialised version of f
+All of these other OccNames contain a mixture of alphabetic
+and symbolic characters, and hence cannot possibly clash with
+a user-written type or function name
 
-       in encoded form these appear as Zdfxxx etc
+   $f...       Dict-fun identifiers (from inst decls)
+   $dmop       Default method for 'op'
+   $pnC                n'th superclass selector for class C
+   $wf         Worker for functtoin 'f'
+   $sf..       Specialised version of f
+   T:C         Tycon for dictionary for class C
+   D:C         Data constructor for dictionary for class C
+   NTCo:T       Coercion connecting newtype T with its representation type
+   TFCo:R       Coercion connecting a data family to its respresentation type R
+
+In encoded form these appear as Zdfxxx etc
 
        :...            keywords (export:, letrec: etc.)
 --- I THINK THIS IS WRONG!
@@ -535,15 +540,15 @@ mkDataConWrapperOcc = mk_simple_deriv varName  "$W"
 mkWorkerOcc         = mk_simple_deriv varName  "$w"
 mkDefaultMethodOcc  = mk_simple_deriv varName  "$dm"
 mkDerivedTyConOcc   = mk_simple_deriv tcName   ":"     -- The : prefix makes sure it classifies
-mkClassTyConOcc     = mk_simple_deriv tcName   ":T"    -- as a tycon/datacon
-mkClassDataConOcc   = mk_simple_deriv dataName ":D"    -- We go straight to the "real" data con
+mkClassTyConOcc     = mk_simple_deriv tcName   "T:"    -- as a tycon/datacon
+mkClassDataConOcc   = mk_simple_deriv dataName "D:"    -- We go straight to the "real" data con
                                                        -- for datacons from classes
 mkDictOcc          = mk_simple_deriv varName  "$d"
 mkIPOcc                    = mk_simple_deriv varName  "$i"
 mkSpecOcc          = mk_simple_deriv varName  "$s"
 mkForeignExportOcc  = mk_simple_deriv varName  "$f"
-mkNewTyCoOcc        = mk_simple_deriv tcName  ":Co"
-mkInstTyCoOcc       = mk_simple_deriv tcName  ":CoF"     -- derived from rep ty
+mkNewTyCoOcc        = mk_simple_deriv tcName  "NTCo:"  -- Coercion for newtypes
+mkInstTyCoOcc       = mk_simple_deriv tcName  "TFCo:"   -- Coercion for type functions
 mkEqPredCoOcc      = mk_simple_deriv tcName  "$co"
 
 -- used in derived instances
@@ -603,7 +608,7 @@ mkInstTyTcOcc :: Int                        -- ^ DFun Index
              -> OccName                -- ^ Family name, e.g. @Map@
              -> OccName                -- ^ Nice unique version, e.g. @:R23Map@
 mkInstTyTcOcc index occ
-   = mk_deriv tcName (":R" ++ show index) (occNameString occ)
+   = mk_deriv tcName ("R" ++ show index ++ ":") (occNameString occ)
 \end{code}
 
 \begin{code}