Runa
A little language you can read.
What it is
Runa is a small, readable programming language with a complete interpreter pipeline: a lexer, a Pratt parser, and a tree-walking interpreter supporting closures and recursion. It now handles arrays, while loops, assignment, and higher-order builtins like map, filter, and reduce, and the run(src) function returns output, result, and error so the whole pipeline is testable - 18 tests run real programs. It is a from-scratch, zero-dependency build you can download and run locally.
Lexer → Pratt parser → tree-walking interpreter with closures + recursion, zero-dep. Now with arrays, while loops, assignment, and higher-order builtins (map/filter/reduce). run(src)→{output,result,error} makes the pipeline testable; 18 tests drive real programs.
What's inside
The full source, the tests, and CI. Open it, read it, change it. A zero-dependency core, free, in the MIT spirit.
Run it after unzip
pnpm install && pnpm dev