major refactoring

diff --git a/Data/HList.hs b/Data/HList.hs
index 77ad6cc7e724fa1a2641fa1d451bd9abbe1d7f8b..05dd901214532b337bca9155508373b9dd09eb2a 100644 (file)
--- a/Data/HList.hs
+++ b/Data/HList.hs
@@ -2,14 +2,21 @@ module Data.HList
     ( HList
     , HNil(..)
     , hNil
-    , HCons(..)
-    , hCons
+    , (:*:)(..)
+    , (.*.)
 
     , HExtendable(..)
     , HAppendable(..)
 
-    , (:*:)
-    , (.*.)
+    , Applyable(..)
+    , Applyable2(..)
+
+    , Id(..)
+    , ApplyHAppend(..)
+
+    , HFoldrable(..)
+    , HConcatable(..)
+    , HMappable(..)
     )
     where
 
@@ -28,15 +35,18 @@ instance HList HNil
 hNil :: HNil
 hNil = HNil
 
--- HCons
-data HCons e l
-    = HCons e l
+-- :*:
+infixr 2 :*:
+infixr 2 .*.
+
+data e :*: l
+    = e :*: l
       deriving (Show, Eq, Ord, Read, Typeable)
 
-instance HList l => HList (HCons e l)
+instance HList l => HList (e :*: l)
 
-hCons :: HList l => e -> l -> HCons e l
-hCons = HCons
+(.*.) :: HList l => e -> l -> e :*: l
+(.*.) = (:*:)
 
 -- HExtendable
 class HExtendable e l where
@@ -44,32 +54,91 @@ class HExtendable e l where
     hExtend :: e -> l -> HExtend e l
 
 instance HExtendable e HNil where
-    type HExtend e HNil = HCons e HNil
-    hExtend e nil = hCons e nil
+    type HExtend e HNil = e :*: HNil
+    hExtend e nil = e .*. nil
 
-instance HList l => HExtendable e (HCons e' l) where
-    type HExtend e (HCons e' l) = HCons e (HCons e' l)
-    hExtend e (HCons e' l) = hCons e (hCons e' l)
+instance HList l => HExtendable e (e' :*: l) where
+    type HExtend e (e' :*: l) = e :*: e' :*: l
+    hExtend e (e' :*: l) = e .*. e' .*. l
 
 -- HAppendable
+infixr 1 :++:
+infixr 1 .++.
+
 class HAppendable l l' where
-    type HAppend l l'
-    hAppend :: l -> l' -> HAppend l l'
+    type l :++: l'
+    (.++.) :: l -> l' -> l :++: l'
 
 instance HList l => HAppendable HNil l where
-    type HAppend HNil l = l
-    hAppend _ l = l
-
-instance (HAppendable l l',
-          HList (HAppend l l')) => HAppendable (HCons e l) l' where
-    type HAppend (HCons e l) l' = HCons e (HAppend l l')
-    hAppend (HCons e l) l' = hCons e (hAppend l l')
-
--- :*:
-infixr 2 :*:
-infixr 2 .*.
-
-type e :*: l = HCons e l
-
-(.*.) :: HExtendable e l => e -> l -> HExtend e l
-e .*. l = hExtend e l
+    type HNil :++: l = l
+    _ .++. l = l
+
+instance ( HAppendable l l'
+         , HList (l :++: l')
+         ) => HAppendable (e :*: l) l' where
+    type (e :*: l) :++: l' = e :*: (l :++: l')
+    (e :*: l) .++. l' = e .*. (l .++. l')
+
+-- Applyable
+class Applyable f a where
+    type Apply f a
+    apply :: f -> a -> Apply f a
+
+-- Applyable2
+class Applyable2 f a b where
+    type Apply2 f a b
+    apply2 :: f -> a -> b -> Apply2 f a b
+
+-- Id
+data Id = Id
+
+instance Applyable Id a where
+    type Apply Id a = a
+    apply _ a = a
+
+-- ApplyHAppend
+data ApplyHAppend = ApplyHAppend
+
+instance HAppendable a b => Applyable2 ApplyHAppend a b where
+    type Apply2 ApplyHAppend a b = a :++: b
+    apply2 _ a b = a .++. b
+
+-- HFoldrable
+class HFoldrable f v l where
+    type HFoldr f v l
+    hFoldr :: f -> v -> l -> HFoldr f v l
+
+instance HFoldrable f v HNil where
+    type HFoldr f v HNil = v
+    hFoldr _ v _ = v
+
+instance ( HFoldrable f v l
+         , Applyable2 f e (HFoldr f v l)
+         ) => HFoldrable f v (e :*: l) where
+    type HFoldr f v (e :*: l) = Apply2 f e (HFoldr f v l)
+    hFoldr f v (e :*: l) = apply2 f e (hFoldr f v l)
+
+-- HConcatable
+class HConcatable ls where
+    type HConcat ls
+    hConcat :: ls -> HConcat ls
+
+instance HFoldrable ApplyHAppend HNil ls => HConcatable ls where
+    type HConcat ls = HFoldr ApplyHAppend HNil ls
+    hConcat ls = hFoldr ApplyHAppend hNil ls
+
+-- HMappable
+class HMappable f l where
+    type HMap f l
+    hMap :: f -> l -> HMap f l
+
+instance HMappable f HNil where
+    type HMap f HNil = HNil
+    hMap _ _ = HNil
+
+instance ( HList (HMap f xs)
+         , Applyable f x
+         , HMappable f xs
+         ) => HMappable f (x :*: xs) where
+    type HMap f (x :*: xs) = Apply f x :*: HMap f xs
+    hMap f (x :*: xs) = apply f x .*. hMap f xs

diff --git a/Database/RRDtool.hs b/Database/RRDtool.hs
index 34867d0f19372ac2a80ec50a42feb1ae9944c086..df0fc4863efc084a34695bf3c8e10d44926a1eeb 100644 (file)
--- a/Database/RRDtool.hs
+++ b/Database/RRDtool.hs
@@ -2,6 +2,7 @@ module Database.RRDtool
     ( DataSource(..)
 
     , MentionedVars(..)
+    , ApplyMentionedVarsOf(..)
 
     , Expr
     , CommonExpr
@@ -165,9 +166,18 @@ dsTest = COMPUTE {
            , dsExpr = AverageOf (Const 100 .*. Const 200 .*. HNil)
          }
 
+-- MentionedVars
 class VariableSet (MentionedVarsOf a) => MentionedVars a where
     type MentionedVarsOf a
 
+-- ApplyMentionedVarsOf
+data ApplyMentionedVarsOf = ApplyMentionedVarsOf
+
+instance Applyable ApplyMentionedVarsOf a where
+    type Apply ApplyMentionedVarsOf a = MentionedVarsOf a
+    apply = undefined
+
+-- Expr
 class (Show e, Eq e) => Expr e
 class Expr e => CommonExpr e
 class Expr e => IterativeExpr e
@@ -176,12 +186,12 @@ instance CommonExpr e => IterativeExpr e
 
 class (Show es, Eq es, HList es) => ExprSet es
 instance ExprSet HNil
-instance (Expr e, ExprSet es) => ExprSet (HCons e es)
+instance (Expr e, ExprSet es) => ExprSet (e :*: es)
 
 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)
+instance (CommonExpr e, CommonExprSet es) => CommonExprSet (e :*: es)
 
 
 -- Constants and variable names
@@ -207,7 +217,7 @@ instance VarName vn => MentionedVars (Variable vn) where
 
 class HList vs => VariableSet vs
 instance VariableSet HNil
-instance (VarName vn, VariableSet vs) => VariableSet (HCons vn vs)
+instance (VarName v, VariableSet vs) => VariableSet (v :*: vs)
 
 -- Common operators
 data CommonUnaryOp a
@@ -254,31 +264,45 @@ instance (Expr a, Expr b) =>
 instance (CommonExpr a, CommonExpr b) =>
     CommonExpr (CommonBinaryOp a b)
 
-instance (VariableSet (MentionedVarsOf a),
-          VariableSet (MentionedVarsOf b),
-          VariableSet (HAppend (MentionedVarsOf a) (MentionedVarsOf b))) =>
+instance VariableSet (MentionedVarsOf a :++: MentionedVarsOf b) =>
     MentionedVars (CommonBinaryOp a b) where
         type MentionedVarsOf (CommonBinaryOp a b)
-            = HAppend (MentionedVarsOf a) (MentionedVarsOf 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 VariableSet (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...
 
 data CommonSetOp es
     = AverageOf !es
     deriving (Show, Eq, Ord)
+
 instance ExprSet es => Expr (CommonSetOp es)
 instance CommonExprSet es => CommonExpr (CommonSetOp es)
+instance VariableSet (HConcat (HMap ApplyMentionedVarsOf es)) =>
+    MentionedVars (CommonSetOp es) where
+        type MentionedVarsOf (CommonSetOp es)
+            = HConcat (HMap ApplyMentionedVarsOf es)
 
 data TrendOp vn a
     = Trend      !(Variable vn) !a
@@ -286,6 +310,8 @@ data TrendOp vn a
     deriving (Show, Eq, Ord)
 instance (VarName vn, Expr a) => Expr (TrendOp vn a)
 instance (VarName vn, CommonExpr a) => CommonExpr (TrendOp vn a)
+instance (VarName vn, MentionedVars a) => MentionedVars (TrendOp vn a) where
+    type MentionedVarsOf (TrendOp vn a) = vn :*: MentionedVarsOf a
 
 data VariableShiftPredictOp ss w vn
     = VariableShiftPredictAverage !ss !w !(Variable vn)
@@ -295,16 +321,30 @@ instance (ExprSet ss, Expr w, VarName vn)
     => Expr (VariableShiftPredictOp ss w vn)
 instance (CommonExprSet ss, CommonExpr w, VarName vn)
     => CommonExpr (VariableShiftPredictOp ss w vn)
+instance ( VarName vn
+         , VariableSet (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, VarName vn)
     => Expr (FixedShiftPredictOp sm w vn)
+
 instance (CommonExpr sm, CommonExpr w, VarName vn)
     => CommonExpr (FixedShiftPredictOp sm w vn)
 
+instance ( VarName vn
+         , VariableSet (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
     = Unknown
@@ -312,9 +352,14 @@ data CommonValue
     | NegativeInfinity
     | Now
     deriving (Show, Eq, Ord)
+
 instance Expr CommonValue
+
 instance CommonExpr CommonValue
 
+instance MentionedVars CommonValue where
+    type MentionedVarsOf CommonValue = HNil
+
 -- Iterative special values
 data IterativeValue
     = Previous
@@ -322,15 +367,26 @@ data IterativeValue
     | TakenTime
     | TakenLocalTime
     deriving (Show, Eq, Ord)
+
 instance Expr IterativeValue
+
 instance IterativeExpr IterativeValue
 
+instance MentionedVars IterativeValue where
+    type MentionedVarsOf IterativeValue = HNil
+
+-- Iterative special values of something
 data IterativeValueOf vn
     = PreviousOf !(Variable vn)
     deriving (Show, Eq, Ord)
+
 instance VarName vn => Expr (IterativeValueOf vn)
+
 instance VarName vn => IterativeExpr (IterativeValueOf vn)
 
+instance VarName vn => MentionedVars (IterativeValueOf vn) where
+    type MentionedVarsOf (IterativeValueOf vn) = vn :*: HNil
+
 -- Aggregative operators (fairly restricted due to rrdtool's
 -- restriction)
 data AggregativeUnaryOp vn
@@ -347,9 +403,14 @@ data AggregativeUnaryOp vn
     | LSLInt     !(Variable vn)
     | LSLCorrel  !(Variable vn)
     deriving (Show, Eq, Ord)
+
 instance VarName vn => Expr (AggregativeUnaryOp vn)
+
 instance VarName vn => AggregativeExpr (AggregativeUnaryOp vn)
 
+instance VarName 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
 -- with @*UNKNOWN*@ data.