[project @ 2003-07-03 14:33:18 by simonpj]

[ghc-hetmet.git] / ghc / compiler / rename / RnEnv.lhs

diff --git a/ghc/compiler/rename/RnEnv.lhs b/ghc/compiler/rename/RnEnv.lhs
index 68b09c6..e08a8c0 100644 (file)
--- a/ghc/compiler/rename/RnEnv.lhs
+++ b/ghc/compiler/rename/RnEnv.lhs
@@ -39,7 +39,7 @@ import Module         ( Module, ModuleName, moduleName, mkHomeModule,
 import PrelNames       ( mkUnboundName, intTyConName, 
                          boolTyConName, funTyConName,
                          unpackCStringName, unpackCStringFoldrName, unpackCStringUtf8Name,
-                         eqStringName, printName, 
+                         eqStringName, printName, integerTyConName,
                          bindIOName, returnIOName, failIOName, thenIOName
                        )
 #ifdef GHCI    
@@ -564,9 +564,15 @@ mentioned explicitly, but which might be needed by the type checker.
 implicitStmtFVs source_fvs     -- Compiling a statement
   = stmt_fvs `plusFV` implicitModuleFVs source_fvs
   where
-    stmt_fvs = mkFVs [printName, bindIOName, thenIOName, returnIOName, failIOName]
+    stmt_fvs = mkFVs [printName, bindIOName, thenIOName, returnIOName, failIOName, 
+                     integerTyConName]
                -- These are all needed implicitly when compiling a statement
                -- See TcModule.tc_stmts
+       -- Reason for integerTyConName: consider this in GHCi
+       --      ghci>  []
+       -- We get an ambigous constraint (Show a), which we now default just like
+       -- numeric types... but unless we have the instance decl for Integer we 
+       -- won't find a valid default!
 
 implicitModuleFVs source_fvs
   = mkTemplateHaskellFVs source_fvs    `plusFV`