diagrams/diagrams-cairo — pull request #54 by bergey (2014-09-15 18:21:50+00:00)
Title: port to linear instead of vector-space

`diagrams-cairo` remains specialized to Double, as is the `cairo`
package. Rather than make many calls to `realToFrac`, we should provide
the necessary functions to map this or other functions over every
numeric value in a Diagram.

Only tested on GHC-7.8 so far.