Ørjan Johansen questions

Ørjan Johansen answers

• haskell write to file it if it does not exists before reading
• How to manually manipulate precedence of special expressions in Parsec?
• Constraints in Closed Type Families
• convert double to GLfloat in Haskell
• Is is possible to refer to Type Variables in pattern matching?
• Why does adding a data type as constraint to type declaration result in matching error instead of a more correct error?
• How to define superclass?
• What does $! mean / do in Haskell? [duplicate]
• Haskell, QuickCheck, falsify a (wrong) property:
• Scotty post type wont allow effects