Skip to content

Instantly share code, notes, and snippets.

@shigemk2 shigemk2/nudge.hs
Created Mar 4, 2015

Embed
What would you like to do?
data Point = Point Float Float deriving (Show)
data Shape = Circle Point Float | Rectangle Point Point deriving (Show)
area :: Shape -> Float
area (Circle _ r) = pi * r ^ 2
area (Rectangle (Point x1 y1) (Point x2 y2))
= (abs $ x2 - x1) * (abs $ y2 - y1)
nudge :: Shape -> Float -> Float -> Shape
nudge (Circle (Point x y) r) a b = Circle (Point (x+a) (y+b)) r
nudge (Rectangle (Point x1 y1) (Point x2 y2)) a b
= Rectangle (Point (x1+a) (y1+b)) (Point (x2+a) (y2+b))
-- 指定したサイズの図形を原点に作る補助関数を作って、それから移動させる
baseCircle :: Float -> Shape
baseCircle r = Circle (Point 0 0) r
-- 幅と高さを取って、左下の頂点が原点にある長方形を作る関数
baseRect :: Float -> Float -> Shape
baseRect width height = Rectangle (Point 0 0) (Point width height)
main = do
print $ area (Rectangle (Point 0 0) (Point 100 100))
print $ area (Circle (Point 0 0) 24)
print $ nudge (Circle (Point 34 34) 10) 5 10
print $ nudge (baseRect 40 100) 60 23
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.