evansb

{-# LANGUAGE InstanceSigs #-}

import Control.Applicative
import Control.Monad
import Control.Monad.Trans.Writer
-- Here is a direct style pythagoras function
-- There are two noticeable things in the function body.
-- 1. Evaluation order of x * x vs y * y is unknown/implicit.
-- 2. We don't care what happens to the final value (implicit continuation).
pyth :: (Floating a) => a -> a -> a

evansb

module Main where

import Data.Char
import Data.Map

-- Shunting - Yard algorithm for Reverse Polish Notation
data Token = Number Int | ParenOpen | ParenClose
             | AddOp | MulOp  | DivOp | SubOp
            deriving (Show, Eq)