X-Git-Url: http://git.cielonegro.org/gitweb.cgi?a=blobdiff_plain;f=Database%2FRRDtool.hs;h=6b5734076a4ab446f02aba82e11438fa648e3dd3;hb=2c2948fbfa1b730beafa2dc8a5c6c81de54f2920;hp=45ae91a3a36da7f675fca245a6de2c66abbcf07d;hpb=1376286d127998a72ca99d2809405355eafe69cc;p=hs-rrdtool.git

diff --git a/Database/RRDtool.hs b/Database/RRDtool.hs
index 45ae91a..6b57340 100644
--- a/Database/RRDtool.hs
+++ b/Database/RRDtool.hs
@@ -1,16 +1,21 @@
 module Database.RRDtool
     ( DataSource(..)
 
-    , Expr
-    , CommonExpr
+    , MentionedVars(..)
+    , ApplyMentionedVarsOf(..)
+
+    , IsExpr
+    , IsCommonExpr
     , IterativeExpr
-    , AggregativeExpr
+    , IsAggregativeExpr
 
-    , ExprSet
-    , CommonExprSet
+    , IsExprSet
+    , IsCommonExprSet
 
     , Constant(..)
+    , IsVarName(..)
     , Variable(..)
+    , IsVariableSet
     , CommonUnaryOp(..)
     , CommonBinaryOp(..)
     , CommonTrinaryOp(..)
@@ -135,7 +140,7 @@ data DataSource
     -- referred to as \"virtual\" or \"computed\" columns.
     --
     -- FIXME: doc links
-    | forall a. CommonExpr a => COMPUTE {
+    | forall a. IsCommonExpr a => COMPUTE {
         dsName :: !String
         -- |rpn-expression defines the formula used to compute the
         -- PDPs of a COMPUTE data source from other data sources in
@@ -161,36 +166,56 @@ dsTest = COMPUTE {
            , dsExpr = AverageOf (Const 100 .*. Const 200 .*. HNil)
          }
 
-class (Show e, Eq e) => Expr e
-class Expr e => CommonExpr e
-class Expr e => IterativeExpr e
-class Expr e => AggregativeExpr e
-instance CommonExpr e => IterativeExpr e
+-- MentionedVars
+class IsVariableSet (MentionedVarsOf a) => MentionedVars a where
+    type MentionedVarsOf a
+
+-- ApplyMentionedVarsOf
+data ApplyMentionedVarsOf = ApplyMentionedVarsOf
 
---class MentionedVars
+instance Applyable ApplyMentionedVarsOf a where
+    type Apply ApplyMentionedVarsOf a = MentionedVarsOf a
+    apply = undefined
 
-class (Show es, Eq es, HList es) => ExprSet es
-instance ExprSet HNil
-instance (Expr e, ExprSet es) => ExprSet (HCons e es)
+-- IsExpr
+class (Show e, Eq e) => IsExpr e
+class IsExpr e => IsCommonExpr e
+class IsExpr e => IterativeExpr e
+class IsExpr e => IsAggregativeExpr e
 
-class (Show es, Eq es, HList es) => CommonExprSet es
-instance CommonExprSet es => ExprSet es
-instance CommonExprSet HNil
-instance (CommonExpr e, CommonExprSet es) => CommonExprSet (HCons e es)
+class (Show es, Eq es, HList es) => IsExprSet es
+instance IsExprSet HNil
+instance (IsExpr e, IsExprSet es) => IsExprSet (e :*: es)
+
+class (Show es, Eq es, HList es) => IsCommonExprSet es
+instance IsCommonExprSet HNil
+instance (IsCommonExpr e, IsCommonExprSet es) => IsCommonExprSet (e :*: es)
 
 
 -- Constants and variable names
 data Constant
     = Const !Double
     deriving (Show, Eq, Ord)
-instance Expr Constant
-instance CommonExpr Constant
+instance IsExpr Constant
+instance IsCommonExpr Constant
+instance MentionedVars Constant where
+    type MentionedVarsOf Constant = HNil
 
-class (Show a, Eq a) => Variable a where
+class (Show a, Eq a, Ord a) => IsVarName a where
     varName :: a -> String
 
-instance Variable a => Expr a
-instance Variable a => CommonExpr a
+data Variable vn
+    = Variable !vn
+    deriving (Show, Eq, Ord)
+
+instance IsVarName vn => IsExpr (Variable vn)
+instance IsVarName vn => IsCommonExpr (Variable vn)
+instance IsVarName vn => MentionedVars (Variable vn) where
+    type MentionedVarsOf (Variable vn) = vn :*: HNil
+
+class HList vs => IsVariableSet vs
+instance IsVariableSet HNil
+instance (IsVarName v, IsVariableSet vs) => IsVariableSet (v :*: vs)
 
 -- Common operators
 data CommonUnaryOp a
@@ -208,8 +233,10 @@ data CommonUnaryOp a
     | Rad2Deg    !a
     | Abs        !a
     deriving (Show, Eq, Ord)
-instance Expr a => Expr (CommonUnaryOp a)
-instance CommonExpr a => CommonExpr (CommonUnaryOp a)
+instance IsExpr a => IsExpr (CommonUnaryOp a)
+instance IsCommonExpr a => IsCommonExpr (CommonUnaryOp a)
+instance IsVariableSet (MentionedVarsOf a) => MentionedVars (CommonUnaryOp a) where
+    type MentionedVarsOf (CommonUnaryOp a) = MentionedVarsOf a
 
 data CommonBinaryOp a b
     = !a :<:  !b
@@ -228,19 +255,38 @@ data CommonBinaryOp a b
     | AddNaN !a !b
     | AtanXY !a !b
     deriving (Show, Eq, Ord)
-instance (Expr a, Expr b)
-    => Expr (CommonBinaryOp a b)
-instance (CommonExpr a, CommonExpr b)
-    => CommonExpr (CommonBinaryOp a b)
+
+instance (IsExpr a, IsExpr b) =>
+    IsExpr (CommonBinaryOp a b)
+
+instance (IsCommonExpr a, IsCommonExpr b) =>
+    IsCommonExpr (CommonBinaryOp a b)
+
+instance IsVariableSet (MentionedVarsOf a :++: MentionedVarsOf b) =>
+    MentionedVars (CommonBinaryOp a b) where
+        type MentionedVarsOf (CommonBinaryOp a b)
+            = MentionedVarsOf a :++: MentionedVarsOf b
+        
 
 data CommonTrinaryOp a b c
     = If !a !b !c
     | Limit !a !b !c
     deriving (Show, Eq, Ord)
-instance (Expr a, Expr b, Expr c)
-    => Expr (CommonTrinaryOp a b c)
-instance (CommonExpr a, CommonExpr b, CommonExpr c)
-    => CommonExpr (CommonTrinaryOp a b c)
+
+instance (IsExpr a, IsExpr b, IsExpr c)
+    => IsExpr (CommonTrinaryOp a b c)
+
+instance (IsCommonExpr a, IsCommonExpr b, IsCommonExpr c)
+    => IsCommonExpr (CommonTrinaryOp a b c)
+
+instance IsVariableSet (MentionedVarsOf a :++:
+                        MentionedVarsOf b :++:
+                        MentionedVarsOf c) =>
+    MentionedVars (CommonTrinaryOp a b c) where
+        type MentionedVarsOf (CommonTrinaryOp a b c)
+            = MentionedVarsOf a :++:
+              MentionedVarsOf b :++:
+              MentionedVarsOf c
 
 -- SORT and REV can't be expressed in this way as they pushes possibly
 -- multiple values onto the stack...
@@ -248,33 +294,54 @@ instance (CommonExpr a, CommonExpr b, CommonExpr c)
 data CommonSetOp es
     = AverageOf !es
     deriving (Show, Eq, Ord)
-instance ExprSet es => Expr (CommonSetOp es)
-instance CommonExprSet es => CommonExpr (CommonSetOp es)
 
-data TrendOp v a
-    = Trend      !v !a
-    | TrendNan   !v !a
+instance IsExprSet es => IsExpr (CommonSetOp es)
+instance (IsExprSet es, IsCommonExprSet es) => IsCommonExpr (CommonSetOp es)
+instance IsVariableSet (HConcat (HMap ApplyMentionedVarsOf es)) =>
+    MentionedVars (CommonSetOp es) where
+        type MentionedVarsOf (CommonSetOp es)
+            = HConcat (HMap ApplyMentionedVarsOf es)
+
+data TrendOp vn a
+    = Trend      !(Variable vn) !a
+    | TrendNan   !(Variable vn) !a
     deriving (Show, Eq, Ord)
-instance (Variable v, Expr a) => Expr (TrendOp v a)
-instance (Variable v, CommonExpr a) => CommonExpr (TrendOp v a)
+instance (IsVarName vn, IsExpr a) => IsExpr (TrendOp vn a)
+instance (IsVarName vn, IsCommonExpr a) => IsCommonExpr (TrendOp vn a)
+instance (IsVarName vn, MentionedVars a) => MentionedVars (TrendOp vn a) where
+    type MentionedVarsOf (TrendOp vn a) = vn :*: MentionedVarsOf a
 
-data VariableShiftPredictOp ss w v
-    = VariableShiftPredictAverage !ss !w !v
-    | VariableShiftPredictSigma   !ss !w !v
+data VariableShiftPredictOp ss w vn
+    = VariableShiftPredictAverage !ss !w !(Variable vn)
+    | VariableShiftPredictSigma   !ss !w !(Variable vn)
     deriving (Show, Eq, Ord)
-instance (ExprSet ss, Expr w, Variable v)
-    => Expr (VariableShiftPredictOp ss w v)
-instance (CommonExprSet ss, CommonExpr w, Variable v)
-    => CommonExpr (VariableShiftPredictOp ss w v)
-
-data FixedShiftPredictOp sm w v
-    = FixedShiftPredictAverage !sm !w !v
-    | FixedShiftPredictSigma   !sm !w !v
+instance (IsExprSet ss, IsExpr w, IsVarName vn)
+    => IsExpr (VariableShiftPredictOp ss w vn)
+instance (IsExprSet ss, IsCommonExprSet ss, IsCommonExpr w, IsVarName vn)
+    => IsCommonExpr (VariableShiftPredictOp ss w vn)
+instance ( IsVarName vn
+         , IsVariableSet (MentionedVarsOf ss :++: MentionedVarsOf w)
+         ) => MentionedVars (VariableShiftPredictOp ss w vn) where
+    type MentionedVarsOf (VariableShiftPredictOp ss w vn)
+        = vn :*: (MentionedVarsOf ss :++: MentionedVarsOf w)
+
+-- FixedShiftPredictOp
+data FixedShiftPredictOp sm w vn
+    = FixedShiftPredictAverage !sm !w !(Variable vn)
+    | FixedShiftPredictSigma   !sm !w !(Variable vn)
     deriving (Show, Eq, Ord)
-instance (Expr sm, Expr w, Variable v)
-    => Expr (FixedShiftPredictOp sm w v)
-instance (CommonExpr sm, CommonExpr w, Variable v)
-    => CommonExpr (FixedShiftPredictOp sm w v)
+
+instance (IsExpr sm, IsExpr w, IsVarName vn)
+    => IsExpr (FixedShiftPredictOp sm w vn)
+
+instance (IsCommonExpr sm, IsCommonExpr w, IsVarName vn)
+    => IsCommonExpr (FixedShiftPredictOp sm w vn)
+
+instance ( IsVarName vn
+         , IsVariableSet (MentionedVarsOf sm :++: MentionedVarsOf w)
+         ) => MentionedVars (FixedShiftPredictOp sm w vn) where
+    type MentionedVarsOf (FixedShiftPredictOp sm w vn)
+        = vn :*: (MentionedVarsOf sm :++: MentionedVarsOf w)
 
 -- Common special values
 data CommonValue
@@ -283,8 +350,13 @@ data CommonValue
     | NegativeInfinity
     | Now
     deriving (Show, Eq, Ord)
-instance Expr CommonValue
-instance CommonExpr CommonValue
+
+instance IsExpr CommonValue
+
+instance IsCommonExpr CommonValue
+
+instance MentionedVars CommonValue where
+    type MentionedVarsOf CommonValue = HNil
 
 -- Iterative special values
 data IterativeValue
@@ -293,33 +365,49 @@ data IterativeValue
     | TakenTime
     | TakenLocalTime
     deriving (Show, Eq, Ord)
-instance Expr IterativeValue
+
+instance IsExpr IterativeValue
+
 instance IterativeExpr IterativeValue
 
-data IterativeValueOf v
-    = PreviousOf !v
+instance MentionedVars IterativeValue where
+    type MentionedVarsOf IterativeValue = HNil
+
+-- Iterative special values of something
+data IterativeValueOf vn
+    = PreviousOf !(Variable vn)
     deriving (Show, Eq, Ord)
-instance Variable v => Expr (IterativeValueOf v)
-instance Variable v => IterativeExpr (IterativeValueOf v)
+
+instance IsVarName vn => IsExpr (IterativeValueOf vn)
+
+instance IsVarName vn => IterativeExpr (IterativeValueOf vn)
+
+instance IsVarName vn => MentionedVars (IterativeValueOf vn) where
+    type MentionedVarsOf (IterativeValueOf vn) = vn :*: HNil
 
 -- Aggregative operators (fairly restricted due to rrdtool's
 -- restriction)
-data AggregativeUnaryOp v
-    = Maximum    !v
-    | Minimum    !v
-    | Average    !v
-    | StandardDeviation !v
-    | First      !v
-    | Last       !v
-    | Total      !v
-    | Percent    !v !Constant
-    | PercentNan !v !Constant
-    | LSLSlope   !v
-    | LSLInt     !v
-    | LSLCorrel  !v
+data AggregativeUnaryOp vn
+    = Maximum    !(Variable vn)
+    | Minimum    !(Variable vn)
+    | Average    !(Variable vn)
+    | StandardDeviation !(Variable vn)
+    | First      !(Variable vn)
+    | Last       !(Variable vn)
+    | Total      !(Variable vn)
+    | Percent    !(Variable vn) !Constant
+    | PercentNan !(Variable vn) !Constant
+    | LSLSlope   !(Variable vn)
+    | LSLInt     !(Variable vn)
+    | LSLCorrel  !(Variable vn)
     deriving (Show, Eq, Ord)
-instance Variable v => Expr (AggregativeUnaryOp v)
-instance Variable v => AggregativeExpr (AggregativeUnaryOp v)
+
+instance IsVarName vn => IsExpr (AggregativeUnaryOp vn)
+
+instance IsVarName vn => IsAggregativeExpr (AggregativeUnaryOp vn)
+
+instance IsVarName vn => MentionedVars (AggregativeUnaryOp vn) where
+    type MentionedVarsOf (AggregativeUnaryOp vn) = vn :*: HNil
 
 -- |The 'createRRD' function lets you set up new Round Robin Database
 -- (RRD) files. The file is created at its final, full size and filled