Drop using phantom types #33

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1. cryogenian commented on May 19, 2017

   

   cryogenian

   on May 19, 2017

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   Using Union for this is kinda problematic because we need

   • Be able to have row with fields that are subset of corresponding field in Option and may be missing
   • series can have different configuration --> universal type parameters with Union constraints won't work too --> only existential things like

   newtype TextStyle = TextStyle (Exists Identity) 
   mkTextStyle :: forall r1 r2. Union r1 r2 TextStyleRow => Record r1 -> TextStyle 
   mkTextStyle = unsafeCoerce 
   runTextStyle :: forall res. TextStyle -> (forall r1 r2. Union r1 r2 TextStyleRow => Record r1 -> res) -> res
   runTextStyle = unsafeCoerce runExists
   
   newtype Series = Series (Exists Identity)
   mkLineSeries :: forall r1 r2. Union r1 r2 LineSeriesRow => Record r1 -> Series
   mkLineSeries = unsafeCoerce
   
   mkBarSeries :: forall r1 r2. Union r1 r2 BarSeriesRow => Record r1 -> Series 
   mkBarSeries = unsafeCoerce 
   
   runLineSeries :: forall res. Series -> (forall r1 r2. Union r1 r2 LineSeriesRow => Maybe (Record r1) -> res) -> res
   runLineSeries = ... 
   
   foldSeries 
     :: forall res
      . Series -> 
     -> (forall r1 r2. Union r1 r2 LineSeries => Record r1 -> res)
     -> (forall r1 r2. Union r1 r2 BarSeries => Record r1 -> res) 
     -> ...
     -> res
   

   The second one works but API isn't soo fancy

   mkChart 
     { animationDuration: \i -> i * 100
     , textStyle: mkTextStyle { fontSize: 14 }
     , series: [ mkLineSeries lineSeries, mkBarSeries barSeries ]  
     }