+Overloaded literals. Here mainly becuase it uses isIntTy etc
+
+\begin{code}
+shortCutLit :: OverLitVal -> TcType -> Maybe (HsExpr TcId)
+shortCutLit (HsIntegral i) ty
+ | isIntTy ty && inIntRange i = Just (HsLit (HsInt i))
+ | isWordTy ty && inWordRange i = Just (mkLit wordDataCon (HsWordPrim i))
+ | isIntegerTy ty = Just (HsLit (HsInteger i ty))
+ | otherwise = shortCutLit (HsFractional (fromInteger i)) ty
+ -- The 'otherwise' case is important
+ -- Consider (3 :: Float). Syntactically it looks like an IntLit,
+ -- so we'll call shortCutIntLit, but of course it's a float
+ -- This can make a big difference for programs with a lot of
+ -- literals, compiled without -O
+
+shortCutLit (HsFractional f) ty
+ | isFloatTy ty = Just (mkLit floatDataCon (HsFloatPrim f))
+ | isDoubleTy ty = Just (mkLit doubleDataCon (HsDoublePrim f))
+ | otherwise = Nothing
+
+shortCutLit (HsIsString s) ty
+ | isStringTy ty = Just (HsLit (HsString s))
+ | otherwise = Nothing
+
+mkLit :: DataCon -> HsLit -> HsExpr Id
+mkLit con lit = HsApp (nlHsVar (dataConWrapId con)) (nlHsLit lit)
+
+------------------------------
+hsOverLitName :: OverLitVal -> Name
+-- Get the canonical 'fromX' name for a particular OverLitVal
+hsOverLitName (HsIntegral {}) = fromIntegerName
+hsOverLitName (HsFractional {}) = fromRationalName
+hsOverLitName (HsIsString {}) = fromStringName
+\end{code}