Remove all "otherwise -> error" cases for performance reasons.

[spline3.git] / src / Grid.hs

diff --git a/src/Grid.hs b/src/Grid.hs
index dc52482b0eb3cc2bc88656df24681759b8a4d346..a1058d07f2fa4c89d5bcab914e05a428dccb52f8 100644 (file)
--- a/src/Grid.hs
+++ b/src/Grid.hs
@@ -53,33 +53,27 @@ instance Arbitrary Grid where
       return (make_grid h' fvs)
 
 
--- | The constructor that we want people to use. If we're passed a
---   non-positive grid size, we throw an error.
+-- | The constructor that we want people to use.
+--   Ignore non-positive grid sizes for performance.
 make_grid :: Double -> Values3D -> Grid
-make_grid grid_size values
-    | grid_size <= 0 = error "grid size must be positive"
-    | otherwise = Grid grid_size values
+make_grid grid_size values =
+  Grid grid_size values
 
 
 
 -- | Takes a grid and a position as an argument and returns the cube
---   centered on that position. If there is no cube there (i.e. the
---   position is outside of the grid), it will throw an error.
+--   centered on that position. If there is no cube there, well, you
+--   shouldn't have done that. The omitted "otherwise" case actually
+--   does improve performance.
 cube_at :: Grid -> Int -> Int -> Int -> Cube
-cube_at !g !i !j !k
-    | i < 0      = error "i < 0 in cube_at"
-    | i >= xsize = error "i >= xsize in cube_at"
-    | j < 0      = error "j < 0 in cube_at"
-    | j >= ysize = error "j >= ysize in cube_at"
-    | k < 0      = error "k < 0 in cube_at"
-    | k >= zsize = error "k >= zsize in cube_at"
-    | otherwise = Cube delta i j k fvs' tet_vol
-      where
-        fvs = function_values g
-        (xsize, ysize, zsize) = dims fvs
-        fvs' = make_values fvs i j k
-        delta = h g
-        tet_vol = (1/24)*(delta^(3::Int))
+cube_at !g !i !j !k =
+   Cube delta i j k fvs' tet_vol
+   where
+     fvs = function_values g
+     fvs' = make_values fvs i j k
+     delta = h g
+     tet_vol = (1/24)*(delta^(3::Int))
+
 
 --   The first cube along any axis covers (-h/2, h/2). The second
 --   covers (h/2, 3h/2).  The third, (3h/2, 5h/2), and so on.