X-Git-Url: http://git.cielonegro.org/gitweb.cgi?p=hs-rrdtool.git;a=blobdiff_plain;f=Database%2FRRDtool%2FExpression.hs;h=5c44213e47fb2fa4649b82c489e5d543cc3af79d;hp=f2d2574f93b8a23d70ed0c0e0b05004ffbacd1c5;hb=f34eed5749bdaf7ff7b33230557b30115ae343f3;hpb=16e0b5c01dc848105b3673a72ee6e04f8baae9d9

diff --git a/Database/RRDtool/Expression.hs b/Database/RRDtool/Expression.hs
index f2d2574..5c44213 100644
--- a/Database/RRDtool/Expression.hs
+++ b/Database/RRDtool/Expression.hs
@@ -2,6 +2,7 @@
   EmptyDataDecls,
   FlexibleInstances,
   TypeFamilies,
+  TypeOperators,
   MultiParamTypeClasses,
   UndecidableInstances
   #-}
@@ -14,6 +15,7 @@ module Database.RRDtool.Expression
     , IsIterativeExpr
 
     , IsVarName
+    , hString
 
     , Constant(..)
     , Variable(..)
@@ -32,6 +34,7 @@ module Database.RRDtool.Expression
     where
 
 import Data.HList
+import Data.HList.String
 import Types.Data.Bool
 import Types.Data.Num hiding ((:*:))
 import Types.Data.Ord
@@ -75,13 +78,13 @@ type instance IsIterativeExpr Constant = True
 type instance MentionedVars   Constant = HNil
 
 {- This is what we want to do but GHC can't handle this for now. 
-class ( (HLengthOf str :<=: D255) ~ True
+class ( (HLengthOf str :<=: D19) ~ True
       , HString str
       )
     => IsVarName str
 -}
 type family   IsVarName str
-type instance IsVarName str = ( (HLength str :<=: D255)
+type instance IsVarName str = ( (HLength str :<=: D19)
                                 :&&:
                                 (HAll IsGoodLetterForVarNameA str)
                               )