Here is source code of the priority
queue implementations described in the paper. Note that the code
conforms to Haskell 98 with one small exception: deriving
Show for MinView does not work since the
instance declaration requires a context of the form Show (q
a). This is, however, not legal Haskell 98. Fortunately, both
Hugs 98 (use -98) and GHC 4.0x (use
-fglasgow-exts) provide the necessary extension to the
class system. [Alternatively, delete deriving (Show) and
use Hugs' -u option to activate the built-in printing
mechanism of Hugs.]