X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FCardinal.hs;h=9bd8e1df933b592d877d2e1efe810b44d96092ac;hb=9b9acc3fbb79d737a39a9f4def70621440933095;hp=42b1260bb13f72f530bd725fd89943da1c1d004f;hpb=084d6e31ba1eda1e7c206ff8ff23e8567e2339ce;p=spline3.git diff --git a/src/Cardinal.hs b/src/Cardinal.hs index 42b1260..9bd8e1d 100644 --- a/src/Cardinal.hs +++ b/src/Cardinal.hs @@ -1,6 +1,6 @@ -- | The Cardinal module contains the Cardinal data type, representing --- a cardinal direction (one of the 27 directions surrounding the --- center of a cube. In addition to those 27 directions, we also +-- a cardinal direction (one of the 26 directions surrounding the +-- center of a cube. In addition to those 26 directions, we also -- include the interior point and a number of composite types that -- allow us to perform arithmetic on directions. module Cardinal @@ -46,7 +46,7 @@ data Cardinal = F -- ^ Front deriving (Show, Eq) --- | By making Cardinal an instance of Num, we gain the ability to +-- | By making Cardinal an instance of 'Num', we gain the ability to -- add, subtract, and multiply directions. The results of these -- operations are never actually calculated; the types just keep -- track of which operations were performed in which order. @@ -54,17 +54,17 @@ instance Num Cardinal where x + y = Sum x y x - y = Difference x y x * y = Product x y - negate x = Product (Scalar (-1)) x + negate = Product (Scalar (-1)) abs x = x signum x = x fromInteger x = Scalar (fromIntegral x) --- | Like the Num instance, the Fractional instance allows us to +-- | Like the Num instance, the 'Fractional' instance allows us to -- take quotients of directions. instance Fractional Cardinal where x / y = Quotient x y - recip x = Quotient (Scalar 1) x + recip = Quotient (Scalar 1) fromRational x = Scalar (fromRational x)