Laurelang
論理プログラミング
Laurelang is designed to be a new logic programming language. It implements an abstract machine and bytecode compiler.
There are multiple drivers and compilers written in different languages, but the main implementation is written in C.
The project is fully open source. Its sources can be found here. Its website is laurelang.org.
An example of laurelang program describing logic for filtering lists:
-- Determines array to predicate and filtered array
-- with elements corresponding to predicate
: ?filter('T'[], (?('T'))) -> 'T'[].
?filter([], _) -> [].
?filter([x|tail], f) -> fs {
f(x);
append([x], filter(tail, f)) = fs;
}%
?filter([_|tail], f) -> filter(tail, f).