cchalmers questions

cchalmers answers

• How would I use lens in Haskell to duplicate Python's enumerate?
• How to use lenses to look up a value in a map, increase it or set it to a default value
• Do GHC REWRITE pragmas have to be type preserving?
• stepping into zipper with `to` lens
• Just when are unsafeVacuous, #., and .# unsafe?
• Is there a generic function that takes a data structure and returns all ints in it?
• Can't find inerface-file declaration for variable
• Top-level expression evaluation at compile time
• Haskell Performance by Example
• How to model a currencies, money, and banks that exchange money between currencies?