Use OPTIONS rather than OPTIONS_GHC for pragmas

[ghc-hetmet.git] / compiler / prelude / PrelInfo.lhs

diff --git a/compiler/prelude/PrelInfo.lhs b/compiler/prelude/PrelInfo.lhs
index 31457b2..3fa99f1 100644 (file)
--- a/compiler/prelude/PrelInfo.lhs
+++ b/compiler/prelude/PrelInfo.lhs
@@ -4,6 +4,13 @@
 \section[PrelInfo]{The @PrelInfo@ interface to the compiler's prelude knowledge}
 
 \begin{code}
+{-# OPTIONS -w #-}
+-- The above warning supression flag is a temporary kludge.
+-- While working on this module you are encouraged to remove it and fix
+-- any warnings in the module. See
+--     http://hackage.haskell.org/trac/ghc/wiki/CodingStyle#Warnings
+-- for details
+
 module PrelInfo (
        module MkId,
 
@@ -28,7 +35,6 @@ import PrelNames      ( basicKnownKeyNames,
 import PrimOp          ( PrimOp, allThePrimOps, primOpOcc, primOpTag, maxPrimOpTag )
 import DataCon         ( DataCon )
 import Id              ( Id, idName )
-import MkId            ( mkPrimOpId, wiredInIds )
 import MkId            -- All of it, for re-export
 import Name            ( nameOccName )
 import TysPrim         ( primTyCons )
@@ -48,11 +54,30 @@ import Array                ( Array, array, (!) )
 %*                                                                     *
 %************************************************************************
 
-We have two ``builtin name funs,'' one to look up @TyCons@ and
-@Classes@, the other to look up values.
+Notes about wired in things
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+* Wired-in things are Ids/TyCons that are completely known to the compiler.
+  They are global values in GHC, (e.g.  listTyCon :: TyCon).
+
+* A wired in Name contains the thing itself inside the Name: 
+       see Name.wiredInNameTyThing_maybe
+  (E.g. listTyConName contains listTyCon. 
+
+* The name cache is initialised with (the names of) all wired-in things
+
+* The type checker sees if the Name is wired in before looking up 
+  the name in the type environment.  So the type envt itself contains
+  no wired in things.
+
+* MkIface prunes out wired-in things before putting them in an interface file.
+  So interface files never contain wired-in things.
+
 
 \begin{code}
 wiredInThings :: [TyThing]
+-- This list is used only to initialise HscMain.knownKeyNames
+-- to ensure that when you say "Prelude.map" in your source code, you
+-- get a Name with the correct known key
 wiredInThings          
   = concat
     [          -- Wired in TyCons and their implicit Ids