Hi, I wanted to chime in with some notes about performance for guile-log and kanren on guile-log.
For the einstein case, The story is that I compiled the c-code with -O3 and added faster versions with reduced call overhead for functions loaded from c under by using 5 extra vm instructions. Guile-log went down to about 50ms for the stack version and 200 for the assoq version. Kanren ontop guile-log with the stack version was about the same e.g. 200ms I then really wanted to see the performance assuming that you profile and code the hotspots in C. Doing this I could bring down the test to 25ms for stack based and 125ms for the assoq version. I know that compiled prolog performs about 12-14ms and about 50% of guile-log is in the overhead of the VM and the cost of constructing closures. Coding the algorithms in C is pretty awkward and you typeically cannot do that straightforwardly. The reason is that one need to handle tail calls and closures in c-land as well. I do have a framework to make such C-code. But then the guile-log version on C is isolated from Scheme. It would be really cool to make them interoperate. Anyhow Have fun Stefan
