TPG в Python

data Figure =  Circle Double Double Double 
         | Rectangle Double Double Double Double
         | Triangle Double Double Double Double Double Double
         | TextField Double Double String Font deriving (Eq, Show)
 
mini :: (Double , Double , Double) -> Double
mini (a,b,c) = if (a<=b)&&(a<=c) then a else if (b<=a)&&(b<=c) then b else c
 
maxi :: (Double , Double , Double) -> Double
maxi (a,b,c) = if (a>=b)&&(a>=c) then a else if (b>=a)&&(b>=c) then b else c
 
charSize :: Font -> Double
charSize Courier = 15
charSize Lucida = 14
charSize Fixedsys = 13
 
distance :: Double -> Double -> Double -> Double -> Double
distance a b c d = sqrt ((c-a)^2+(d-b)^2)
 
data Font = Courier | Lucida | Fixedsys deriving (Eq , Show)
dl :: [a] -> Double
dl [] = 0
dl s = 1.0 + dl (tail s)
 
area :: Figure -> Double
area (Circle x y r) = 3.141592 * r * r
area (Rectangle a b c d) = (c-a)*(d-b)
area (Triangle x1 y1 x2 y2 x3 y3) = 
      let {d1 = distance x1 y1 x2 y2 ; d2 = distance x3 y3 x2 y2 ; d3 = distance x1 y1 x3 y3 ; p = (d1+d2+d3)/2}
         in sqrt (p*(p-d1)*(p-d2)*(p-d3))
area (TextField x y str fnt) = (dl str) * (charSize fnt) * 7
 
getRectangles :: [Figure] -> [Figure]
getRectangles [] = []
getRectangles ((Rectangle a b c d):xs)  = (Rectangle a b c d):(getRectangles xs)
getRectangles (_:xs) = getRectangles xs
 
getBound :: Figure -> Figure
getBound (Circle x y r) = (Rectangle (x-r) (y+r) (x+r) (y-r))
getBound (Rectangle a b c d) = Rectangle a b c d
getBound (Triangle x1 y1 x2 y2 x3 y3) = Rectangle (mini (x1,x2,x3)) (maxi (y1,y2,y3)) (maxi (x1,x2,x3)) (mini (y1,y2,y3))
getBound (TextField x y str fnt) = Rectangle x (y+charSize (fnt)) (x+7*dl(str)) y
 
getBounds :: [Figure] -> [Figure]
getBounds [] = []
getBounds s = (getBound (head s)):(getBounds (tail s))
 
beInRect :: Double -> Double -> Figure -> Bool
beInRect x y (Rectangle a b c d) = if (x>=a && x<=c && y<=b && y>=d) then True else False
 
getFigure :: Double -> Double -> [Figure] -> Maybe Figure
getFigure x y [] = Nothing
getFigure x y (s:xs) = if beInRect x y (getBound s)  then Just s else getFigure x y xs
 
move :: Figure -> Double -> Double -> Figure
move (Circle x y r) z1 z2 = (Circle (x+z1) (y+z2) r)
move (Rectangle a b c d) z1 z2 = Rectangle (a+z1) (b+z2) (c+z1) (d+z2)
move (Triangle x1 y1 x2 y2 x3 y3) z1 z2 = (Triangle (x1+z1) (y1+z2) (x2+z1) (y2+z2) (x3+z1) (y3+z2))
move (TextField x y str fnt) z1 z2 = (TextField (x+z1) (y+z2) str fnt)