Church alpha 3

This release fixes some bugs:

http://subvert-the-dominant-paradigm.net/~jewel/church/church-alpha-3.tar.gz

  • When I first wrote some of the church compiler passes and the sexp parser I used global variables to store state specific to that pass. I knew that only one thread would be running and that these passes didn’t have to be reentrant. Later I added functionality to compile macros on the fly and to compile dispatch matchers. When I did this I tried to rewrite all the modules that used global state, but I missed the sexp parser and this caused some strange bugs later on.
  • When allocating memory for dynamically allocated code, I was storing the address of the memory block in a fixnum. This worked fine until malloc started returning addresses from higher memory which used the most significant two bits in a word. These would get shifted out when tagging a fixnum and yield an invalid address. To work around this I now box the address by storing it in an array