Dimensional is a library providing data types for performing arithmetic with physical quantities and units. Information about the physical dimensions of the quantities/units is embedded in their types and the validity of operations is verified by the type checker at compile time. The boxing and unboxing of numerical values as quantities is done by multiplication and division with units. The library is designed to, as far as is practical, enforce/encourage best practices of unit usage.

For documentation: see Conclusion and usage in the original announcement, the literate haskell code or the examples in the wiki.

For the latest release: download the tarball.

For current code (new repo location 2008-05-10):

darcs get http://code.haskell.org/dimensional/