diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,8 +1,12 @@
+0.8.2
+===
+
+- added Data instances
+
 0.8.1
 ===
 
 - bumped upper bounds for markup-parse and containers.
-
 
 0.8
 ===
diff --git a/chart-svg.cabal b/chart-svg.cabal
--- a/chart-svg.cabal
+++ b/chart-svg.cabal
@@ -1,6 +1,6 @@
 cabal-version: 3.0
 name: chart-svg
-version: 0.8.1.1
+version: 0.8.2.1
 license: BSD-3-Clause
 license-file: LICENSE
 copyright: Tony Day (c) 2017
@@ -87,6 +87,7 @@
     flatparse >=0.5 && <0.6,
     formatn >=0.3 && <0.4,
     harpie >=0.1 && <0.2,
+    lens >=5 && <5.4,
     markup-parse >=0.1 && <0.3,
     mtl >=2.2.2 && <2.4,
     numhask >=0.11 && <0.14,
diff --git a/readme.md b/readme.md
--- a/readme.md
+++ b/readme.md
@@ -8,7 +8,6 @@
 # Usage
 
     :r
-    :set prompt "> "
     :set -XOverloadedLabels
     :set -XOverloadedStrings
     import Chart
@@ -23,12 +22,9 @@
 
 See the haddock documentation for a detailed overview.
 
-# Examples
-
 To redraw all the examples in Chart.Examples
 
     import Chart.Examples
     writeAllExamples
 
-    ok
 
diff --git a/src/Chart/Bar.hs b/src/Chart/Bar.hs
--- a/src/Chart/Bar.hs
+++ b/src/Chart/Bar.hs
@@ -21,6 +21,7 @@
 import Chart.Style
 import Data.Bool
 import Data.Colour
+import Data.Data
 import Data.Foldable
 import Data.FormatN
 import Data.List (transpose)
@@ -79,7 +80,7 @@
     barStacked :: Stacked,
     barLegendOptions :: LegendOptions
   }
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | The official bar options.
 defaultBarOptions :: BarOptions
@@ -197,7 +198,7 @@
     barRowLabels :: [Text],
     barColumnLabels :: [Text]
   }
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | Calculate the Rect range of a bar data set.
 --
diff --git a/src/Chart/Hud.hs b/src/Chart/Hud.hs
--- a/src/Chart/Hud.hs
+++ b/src/Chart/Hud.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE DuplicateRecordFields #-}
-{-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE OverloadedLabels #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE RebindableSyntax #-}
@@ -86,6 +85,7 @@
 import Data.Bifunctor
 import Data.Bool
 import Data.Colour
+import Data.Data
 import Data.Foldable hiding (sum)
 import Data.FormatN
 import Data.List qualified as List
@@ -135,7 +135,9 @@
 -- > priorityv2Example = priorityv1Example & #hudOptions % #titles %~ fmap (first (const (Priority 51)))
 --
 -- ![priorityv2 example](other/priorityv2.svg)
-data Priority a = Priority {priority :: Double, item :: a} deriving (Eq, Ord, Show, Generic, Functor)
+data Priority a
+  = Priority {priority :: Double, item :: a}
+  deriving (Eq, Ord, Show, Generic, Data, Functor)
 
 -- | Heads-up display additions to charts
 newtype Hud = Hud {phud :: Priority (HudChart -> ChartTree)} deriving (Generic)
@@ -149,7 +151,7 @@
   { chartSection :: ChartTree,
     hudSection :: ChartTree
   }
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | A type for Rect to represent the bounding box of a chart.
 type ChartBox = Rect Double
@@ -167,7 +169,7 @@
     HudSection
   | -- | The hud and canvas sections, including style
     HudStyleSection
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | The 'Rect' of a particular 'HudChartSection' of a 'HudChart'
 hudChartBox' :: HudChartSection -> Getter HudChart (Maybe (Rect Double))
@@ -266,7 +268,7 @@
     legends :: [Priority LegendOptions],
     titles :: [Priority TitleOptions]
   }
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 instance Semigroup HudOptions where
   (<>) (HudOptions a c l t) (HudOptions a' c' l' t') =
@@ -334,7 +336,7 @@
     ticks :: Ticks,
     place :: Place
   }
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | The official X-axis
 defaultXAxisOptions :: AxisOptions
@@ -357,7 +359,7 @@
     -- | Which hud-chart section to anchor to
     anchorTo :: HudChartSection
   }
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | The official axis bar
 defaultAxisBar :: AxisBar
@@ -374,7 +376,7 @@
     anchoring :: Double,
     buffer :: Double
   }
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | The official hud title
 defaultTitleOptions :: Text -> TitleOptions
@@ -398,7 +400,7 @@
     textTick :: Maybe TickStyle,
     lineTick :: Maybe TickStyle
   }
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | Common elements across all tick types.
 data TickStyle = TickStyle
@@ -406,7 +408,7 @@
     anchorTo :: HudChartSection,
     buffer :: Double
   }
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | The official glyph tick
 defaultGlyphTickStyleX :: TickStyle
@@ -485,7 +487,7 @@
     TickExact FormatN Int
   | -- | specific labels and placement
     TickPlaced [(Double, Text)]
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | Lens between a FormatN and a Tick.
 formatN' :: Lens' Tick (Maybe FormatN)
@@ -546,7 +548,7 @@
 defaultTick = TickRound (FormatN FSCommaPrec (Just 1) 4 True True) 5 TickExtend
 
 -- | Whether Ticks are allowed to extend the data range
-data TickExtend = TickExtend | NoTickExtend deriving (Eq, Show, Generic)
+data TickExtend = TickExtend | NoTickExtend deriving (Eq, Show, Generic, Data)
 
 -- | options for prettifying axis decorations
 --
@@ -558,7 +560,7 @@
     angledRatio :: Double,
     allowDiagonal :: Bool
   }
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | The official hud adjustments.
 defaultAdjustments :: Adjustments
@@ -586,7 +588,7 @@
     scaleP :: ScaleP,
     legendCharts :: [(Text, [Chart])]
   }
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | The official legend options
 defaultLegendOptions :: LegendOptions
@@ -618,7 +620,7 @@
     anchorTo :: HudChartSection,
     buffer :: Double
   }
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | The official hud frame
 defaultFrameOptions :: FrameOptions
diff --git a/src/Chart/Markup.hs b/src/Chart/Markup.hs
--- a/src/Chart/Markup.hs
+++ b/src/Chart/Markup.hs
@@ -40,6 +40,7 @@
 import Data.Bool
 import Data.ByteString (ByteString, intercalate, writeFile)
 import Data.Colour
+import Data.Data
 import Data.FormatN
 import Data.Maybe
 import Data.Path
@@ -408,7 +409,7 @@
     cssOptions :: CssOptions,
     renderStyle :: RenderStyle
   }
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | The official markup options
 defaultMarkupOptions :: MarkupOptions
@@ -427,7 +428,11 @@
 |]
 
 -- | CSS glyphShape rendering options
-data ShapeRendering = UseGeometricPrecision | UseCssCrisp | NoShapeRendering deriving (Show, Eq, Generic)
+data ShapeRendering
+  = UseGeometricPrecision
+  | UseCssCrisp
+  | NoShapeRendering
+  deriving (Eq, Show, Generic, Data)
 
 -- | CSS prefer-color-scheme options
 data PreferColorScheme
@@ -436,13 +441,15 @@
   | PreferDark
   | PreferLight
   | PreferNormal
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | css options
 --
 -- >>> defaultCssOptions
 -- CssOptions {shapeRendering = NoShapeRendering, preferColorScheme = PreferHud, fontFamilies = "\nsvg { font-family: system-ui,-apple-system,\"Segoe UI\",Roboto,\"Helvetica Neue\",Arial,\"Noto Sans\",\"Liberation Sans\",sans-serif,\"Apple Color Emoji\",\"Segoe UI Emoji\",\"Segoe UI Symbol\",\"Noto Color Emoji\";\n}\n\nticktext { font-family: SFMono-Regular,Menlo,Monaco,Consolas,\"Liberation Mono\",\"Courier New\",monospace;\n}\n\n", cssExtra = ""}
-data CssOptions = CssOptions {shapeRendering :: ShapeRendering, preferColorScheme :: PreferColorScheme, fontFamilies :: ByteString, cssExtra :: ByteString} deriving (Show, Eq, Generic)
+data CssOptions
+  = CssOptions {shapeRendering :: ShapeRendering, preferColorScheme :: PreferColorScheme, fontFamilies :: ByteString, cssExtra :: ByteString}
+  deriving (Eq, Show, Generic, Data)
 
 -- | No special shape rendering and default hud responds to user color scheme preferences.
 defaultCssOptions :: CssOptions
@@ -469,7 +476,7 @@
     hudOptions :: HudOptions,
     chartTree :: ChartTree
   }
-  deriving (Generic, Eq, Show)
+  deriving (Eq, Show, Generic, Data)
 
 -- | Processes the hud options and turns them into charts, rescales the existing charts, resets the hud options to mempty, and turns on 'ScalePArea' in chart styles.
 --
diff --git a/src/Chart/Primitive.hs b/src/Chart/Primitive.hs
--- a/src/Chart/Primitive.hs
+++ b/src/Chart/Primitive.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE GADTs #-}
 {-# LANGUAGE OverloadedLabels #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE PatternSynonyms #-}
@@ -81,6 +80,7 @@
 import Data.Bifunctor
 import Data.Bool
 import Data.Colour
+import Data.Data
 import Data.Foldable
 import Data.Maybe
 import Data.Path
@@ -114,7 +114,12 @@
 -- > writeChartOptions "other/unit.hs" $ mempty & #hudOptions .~ defaultHudOptions & #chartTree .~ unnamed [r]
 --
 -- ![unit example](other/unit.svg)
-data Chart = Chart {chartStyle :: Style, chartData :: ChartData} deriving (Eq, Show, Generic)
+data Chart
+  = Chart
+  { chartStyle :: Style,
+    chartData :: ChartData
+  }
+  deriving (Eq, Show, Generic, Data)
 
 -- | Data of a 'Chart'
 --
@@ -139,7 +144,7 @@
     PathData [PathData Double]
   | -- | List of rectangles with no 'Style' representation
     BlankData [Rect Double]
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | RectData partial lens
 rectData' :: Lens' ChartData (Maybe [Rect Double])
@@ -248,7 +253,9 @@
 blankChart1 r = Chart defaultStyle (BlankData [r])
 
 -- | A group of charts represented by a 'Tree' of chart lists with labelled branches. The labelling is particularly useful downstream, when groupings become grouped SVG elements with classes or ids.
-newtype ChartTree = ChartTree {tree :: Tree (Maybe Text, [Chart])} deriving (Eq, Show, Generic)
+newtype ChartTree
+  = ChartTree {tree :: Tree (Maybe Text, [Chart])}
+  deriving (Eq, Show, Generic, Data)
 
 -- | Group a list of trees into a new tree.
 group :: Maybe Text -> [ChartTree] -> ChartTree
@@ -540,10 +547,10 @@
 pointize_ (GlyphData xs) = GlyphData xs
 
 -- | Verticle or Horizontal
-data Orientation = Vert | Hori deriving (Eq, Show, Generic)
+data Orientation = Vert | Hori deriving (Eq, Show, Generic, Data)
 
 -- | Whether to stack chart data
-data Stacked = Stacked | NonStacked deriving (Eq, Show, Generic)
+data Stacked = Stacked | NonStacked deriving (Eq, Show, Generic, Data)
 
 -- | The basis for the x-y ratio of a chart
 --
@@ -557,7 +564,7 @@
     ChartAspect
   | -- | Do not rescale charts. The style values should make sense in relation to the data ranges.
     UnscaledAspect
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | Rectangular placement
 data Place
@@ -566,7 +573,7 @@
   | PlaceTop
   | PlaceBottom
   | PlaceAbsolute (Point Double)
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | Flip Place to the opposite side, or negate if 'PlaceAbsolute'.
 --
diff --git a/src/Chart/Style.hs b/src/Chart/Style.hs
--- a/src/Chart/Style.hs
+++ b/src/Chart/Style.hs
@@ -53,6 +53,7 @@
 import Data.Bool
 import Data.ByteString (ByteString)
 import Data.Colour
+import Data.Data
 import Data.List qualified as List
 import Data.Maybe
 import Data.Path
@@ -114,7 +115,7 @@
     -- | shape for glyph chart elements
     glyphShape :: GlyphShape
   }
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | The official default style
 --
@@ -188,7 +189,7 @@
 border s c = defaultRectStyle & set #borderSize s & set #borderColor c & set #color transparent
 
 -- | Whether to escape the common XML escaped characters.
-data EscapeText = EscapeText | NoEscapeText deriving (Eq, Show, Generic)
+data EscapeText = EscapeText | NoEscapeText deriving (Eq, Show, Generic, Data)
 
 -- | the extra area from text styling
 styleBoxText ::
@@ -226,7 +227,7 @@
   | VLineGlyph
   | HLineGlyph
   | PathGlyph ByteString
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | the extra area from glyph styling
 styleBoxGlyph :: Style -> Rect Double
@@ -270,7 +271,7 @@
   ]
 
 -- | line cap style
-data LineCap = LineCapButt | LineCapRound | LineCapSquare deriving (Eq, Show, Generic)
+data LineCap = LineCapButt | LineCapRound | LineCapSquare deriving (Eq, Show, Generic, Data)
 
 -- | svg textifier
 fromLineCap :: (IsString s) => LineCap -> s
@@ -286,7 +287,7 @@
 toLineCap _ = LineCapButt
 
 -- | line cap style
-data LineJoin = LineJoinMiter | LineJoinBevel | LineJoinRound deriving (Eq, Show, Generic)
+data LineJoin = LineJoinMiter | LineJoinBevel | LineJoinRound deriving (Eq, Show, Generic, Data)
 
 -- | svg textifier
 fromLineJoin :: (IsString s) => LineJoin -> s
@@ -302,7 +303,7 @@
 toLineJoin _ = LineJoinMiter
 
 -- | Text Anchor
-data TextAnchor = AnchorMiddle | AnchorStart | AnchorEnd deriving (Eq, Show, Generic)
+data TextAnchor = AnchorMiddle | AnchorStart | AnchorEnd deriving (Eq, Show, Generic, Data)
 
 -- | Convert a 'TextAnchor' to a 'ByteString' label.
 fromTextAnchor :: TextAnchor -> ByteString
@@ -318,7 +319,7 @@
   LT -> AnchorStart
 
 -- | Aligning stacked things.
-data Align = NoAlign | AlignRight | AlignLeft | AlignMid deriving (Eq, Show, Generic)
+data Align = NoAlign | AlignRight | AlignLeft | AlignMid deriving (Eq, Show, Generic, Data)
 
 -- | Scale Projection options
 data ScaleP
@@ -332,7 +333,7 @@
     ScalePMinDim
   | -- | Scale based on the area ratio of a projection
     ScalePArea
-  deriving (Generic, Eq, Show)
+  deriving (Eq, Show, Generic, Data)
 
 -- | given a ScaleP and two Rects, what is the scaling factor for a projection
 --
diff --git a/src/Chart/Surface.hs b/src/Chart/Surface.hs
--- a/src/Chart/Surface.hs
+++ b/src/Chart/Surface.hs
@@ -28,6 +28,7 @@
 import Data.Bifunctor
 import Data.Bool
 import Data.Colour
+import Data.Data
 import Data.Foldable
 import Data.FormatN
 import Data.Maybe
@@ -52,7 +53,7 @@
     -- | Chart range
     soRange :: Rect Double
   }
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | official style
 defaultSurfaceOptions :: SurfaceOptions
@@ -70,7 +71,7 @@
     surfaceColors :: [Colour],
     surfaceRectStyle :: Style
   }
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | The official surface style.
 defaultSurfaceStyle :: SurfaceStyle
@@ -84,7 +85,7 @@
     -- | Surface colour.
     surfaceColor :: Colour
   }
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | surface chart without any hud trimmings
 surfaces :: Style -> [SurfaceData] -> [Chart]
@@ -133,7 +134,7 @@
     sloRect :: Rect Double,
     sloSurfaceStyle :: SurfaceStyle
   }
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | 'AxisOptions' for a surface chart legend.
 surfaceLegendAxisOptions :: AxisOptions
diff --git a/src/Data/Colour.hs b/src/Data/Colour.hs
--- a/src/Data/Colour.hs
+++ b/src/Data/Colour.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE DataKinds #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE QuasiQuotes #-}
@@ -64,6 +63,7 @@
 import Chart.Data
 import Data.Bool (bool)
 import Data.ByteString (ByteString)
+import Data.Data
 import Data.FormatN
 import Data.List qualified as List
 import Data.String.Interpolate
@@ -88,19 +88,9 @@
 -- >>> import Chart
 -- >>> import Optics.Core
 
--- | Colour type for the library, wrapping 'Color'.
-newtype Colour = Colour'
-  { color' :: Color (Alpha RGB) Double
-  }
-  deriving (Eq, Generic)
-
--- | Constructor pattern.
---
--- > Colour red green blue alpha
-pattern Colour :: Double -> Double -> Double -> Double -> Colour
-pattern Colour r g b a = Colour' (ColorRGBA r g b a)
-
-{-# COMPLETE Colour #-}
+-- | Colour type for the library: red, green, blue, opacity in [0,1].
+data Colour = Colour Double Double Double Double
+  deriving (Eq, Generic, Data)
 
 instance Show Colour where
   show (Colour r g b a) =
diff --git a/src/Data/Path.hs b/src/Data/Path.hs
--- a/src/Data/Path.hs
+++ b/src/Data/Path.hs
@@ -45,6 +45,7 @@
 where
 
 import Chart.Data
+import Data.Data
 import GHC.Generics
 import Geom2D.CubicBezier qualified as B
 import NumHask.Prelude
@@ -78,7 +79,7 @@
     QuadP (Point a) (Point a)
   | -- arc
     ArcP (ArcInfo a) (Point a)
-  deriving (Show, Eq, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | View the Point part of a PathData
 pointPath :: PathData a -> Point a
@@ -151,7 +152,7 @@
     -- | sweep means clockwise
     clockwise :: Bool
   }
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | Specification of an Arc using positional referencing as per SVG standard.
 data ArcPosition a = ArcPosition
@@ -159,7 +160,7 @@
     posEnd :: Point a,
     posInfo :: ArcInfo a
   }
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | Arc specification based on centroidal interpretation.
 --
@@ -176,7 +177,7 @@
     -- | difference between ending point angle and starting point angle
     angdiff :: a
   }
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | convert from an ArcPosition spec to ArcCentroid spec.
 --
@@ -292,7 +293,7 @@
     -- | control point
     qposControl :: Point a
   }
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | Quadratic bezier curve with control point expressed in polar terms normalised to the start - end line.
 data QuadPolar a = QuadPolar
@@ -303,7 +304,7 @@
     -- | control point in terms of distance from and angle to the qp0 - qp2 line
     qpolControl :: Polar a
   }
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | Convert from a positional to a polar representation of a cubic bezier.
 --
@@ -378,7 +379,7 @@
     -- | control point 2
     cposControl2 :: Point a
   }
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | A polar representation of a cubic bezier with control points expressed as polar and normalised to the start - end line.
 data CubicPolar a = CubicPolar
@@ -391,7 +392,7 @@
     -- | control point in terms of distance from and angle to the start end line
     cpolControl2 :: Polar a
   }
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | Convert from a positional to a polar representation of a cubic bezier.
 --
diff --git a/src/Data/Path/Parser.hs b/src/Data/Path/Parser.hs
--- a/src/Data/Path/Parser.hs
+++ b/src/Data/Path/Parser.hs
@@ -22,6 +22,7 @@
 import Control.Monad.State.Lazy
 import Data.ByteString (ByteString, intercalate)
 import Data.Char hiding (isDigit)
+import Data.Data
 import Data.FormatN
 import Data.Path (ArcInfo (ArcInfo), PathData (..))
 import Data.Text.Encoding (encodeUtf8)
@@ -209,7 +210,7 @@
     EllipticalArc !Origin ![(Double, Double, Double, Bool, Bool, Point Double)]
   | -- | Close the path, Z or z svg path command.
     EndPath
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 -- | Tell if a path command is absolute (in the current
 -- user coordiante) or relative to the previous point.
@@ -218,7 +219,7 @@
     OriginAbsolute
   | -- | Next point relative to the previous
     OriginRelative
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 pointToSvgCoords :: Point Double -> Point Double
 pointToSvgCoords (Point x y) = Point x (-y)
@@ -307,7 +308,7 @@
     -- | last control point
     curControl :: Maybe (Point Double)
   }
-  deriving (Eq, Show, Generic)
+  deriving (Eq, Show, Generic, Data)
 
 stateCur0 :: PathCursor
 stateCur0 = PathCursor zero zero Nothing