Haskell spaces

-- Display the combined area and centre of a list of shapes.

module Compound (combine) where

import Shape

-- Take a list of lines, convert into a list of shapes,
-- and then find and report the combined centre and area.

combine :: [String] -> String
combine input = "Centre " ++ show(finalCentroid(input)) ++ ", area " ++ show (totalArea(input))

-- Work out the total area of all shapes

totalArea :: [String] -> Double
totalArea[] = 0
totalArea (x:xs) = area (shape x) + totalArea xs

-- Work out the total of all x co-ordinates

centroidX :: [String] -> Double
centroidX [] = 0
centroidX (x:xs) = fst(centre (shape x)) + (centroidX xs)

-- Work out the total for all y co-ordinates

centroidY :: [String] -> Double
centroidY[] = 0
centroidY (x:xs) = snd(centre (shape x)) + centroidY xs

finalCentroid :: [String] -> Point
finalCentroid (x:xs) = ((centroidX (x:xs))/(totalArea (x:xs)), (centroidY (x:xs))/(totalArea (x:xs)))