:
forms a complex number from its real and imaginary rectangular components.
Read as "has type":
> length :: [a] -> Int
"Length has type list-of-'a' to Int"
Or "has kind" (GHC specific):
> Either :: * -> * -> *
leftmost element and the rest of the sequence
the sequence minus the rightmost element, and the rightmost element
Creates a test from the specified Testable, with the specified label attached to it.
Since Test is Testable, this can be used as a shorthand way of attaching a TestLabel to one or more tests.