[richard_shelton]

it's interesting to mention that both Alan Kay (see "The early history of Smalltalk") and John McCarthy (see "advice taker") have very high opinion of logic programming.

Thanks for showing your code! I just placed my minimalist DSL tools and decided to use "Halt Problem" as an example. Here is my code: https://github.com/true-grue/dsl-tools

[fusiongyro]

Very beautiful code! Thanks for sharing it, I really like the simplicity of your parser combinators.

[richard_shelton]

Thank you very much! I decided to place my DSL tools (they contain a tiny amount of code, but I've used them successfully in a number of compiler projects) on github and just started looking for some illustrative examples. And your solution for Halt Problem (never heard about this problem before -- I mean this reddit challenge, of course, not Rice's theorem) appeared just in a right time. Thank you! :)

As a side note. It would be interesting to investigate power of a Prolog-like language which has terms, term variables, pattern matching (maybe even without full unification) and only local backtracking. Plus an ability to make user-defined execution strategies (tree traversals etc) in the form of combinators. I already use most of these constucts in dsl_match module and I got my inspiration mostly from Stratego/XT. Still it would be good to see similiar general-purpose language and compare its expressiveness with Prolog.