This is an interpreter for a stack-based language that combines elements of Kitten and Lua. I wrote this back in high school to practice Haskell, so it might not be the most idiomatic Haskell code. A description of the syntax is in "sik.hs" and some examples are in "tests.hs". Run by making a file with a ".sk" extension and passing its name without the extension to the interpreter.
Variable names are not allowed to contain digits and can be written adjacent with integer literals, which might be useful for code golf.