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Twinside / Rasterific

A drawing engine in Haskell
BSD 3-Clause "New" or "Revised" License
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Build failure with GHC 8.4 #37

Closed DanBurton closed 6 years ago

DanBurton commented 6 years ago

Add semigroup instances. See also: https://ghc.haskell.org/trac/ghc/wiki/Migration/8.4#SemigroupMonoidsuperclasses

[ 6 of 29] Compiling Graphics.Rasterific.Transformations ( src/Graphics/Rasterific/Transformations.hs, dist/build/Graphics/Rasterific/Transformations.o )

src/Graphics/Rasterific/Transformations.hs:56:10: error:
    • No instance for (Semigroup Transformation)
        arising from the superclasses of an instance declaration
    • In the instance declaration for ‘Monoid Transformation’
   |
56 | instance Monoid Transformation where
   |          ^^^^^^^^^^^^^^^^^^^^^

src/Graphics/Rasterific/Transformations.hs:103:5: error:
    • No instance for (Semigroup Transformation)
        arising from a use of ‘<>’
    • In the expression:
        translate p <> rotate angle <> translate (negate p)
      In an equation for ‘rotateCenter’:
          rotateCenter angle p
            = translate p <> rotate angle <> translate (negate p)
    |
103 |     translate p <> rotate angle <> translate (negate p)
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^