Hst hst

Implementing built-in functions as keywords

This patch adds support in the CSPM compiler for the built-in CSPM functions. We've implemented these as keywords, instead of trying to pre-seed a root environment with actual function definitions. There are test cases for all of the functions except for “Seq”, since it returns an infinite set. (We can define a “take” function that would allow us to test, at least partially, infinite sequences. But currently we can't define an analogous function for sets.) http://github.com/hst/hst/commit...