Created
January 26, 2015 07:40
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Evaluator for a simple ast. A little mind blowing.
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| import Data.Map | |
| import Control.Monad | |
| number = return | |
| add = liftM2 (+) | |
| multiply = liftM2 (*) | |
| variable = findWithDefault 0 | |
| environment = fromList [("a",3), ("b",4), ("c",7)] | |
| expressionTree = add (variable "a") (multiply (number 2) (variable "b")) | |
| main = print $ expressionTree environment |
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