Eq package:shake

The Eq class defines equality (==) and inequality (/=). All the basic datatypes exported by the Prelude are instances of Eq, and Eq may be derived for any datatype whose constituents are also instances of Eq. The Haskell Report defines no laws for Eq. However, instances are encouraged to follow these properties:

• Reflexivity x == x = True
• Symmetry x == y = y == x
• Transitivity if x == y && y == z = True, then x == z = True
• Extensionality if x == y = True and f is a function whose return type is an instance of Eq, then f x == f y = True
• Negation x /= y = not (x == y)

Minimal complete definition: either == or /=.

Equality of two FILEPATHs. If you call System.Directory.canonicalizePath first this has a much better chance of working. Note that this doesn't follow symlinks or DOSNAM~1s. Similar to normalise, this does not expand "..", because of symlinks.

x == y ==> equalFilePath x y
normalise x == normalise y ==> equalFilePath x y
equalFilePath "foo" "foo/"
not (equalFilePath "/a/../c" "/c")
not (equalFilePath "foo" "/foo")
Posix:   not (equalFilePath "foo" "FOO")
Windows: equalFilePath "foo" "FOO"
Windows: not (equalFilePath "C:" "C:/")