patty VS hebigo

This comment is misleading &| misinformed.

Sum types are built-in [1] for formal parameters. `nil` is only for `ref|ptr` types. In much code you can just use stack allocated value types and there is neither GC concern nor nil concern, but there is also a mode to help: https://nim-lang.github.io/Nim/manual_experimental_strictnot...

Nim has an easy-ish to use Lisp-like syntax macro system where you just receive & process an AST. So, to do the rest you can make libraries adding the feature without relying upon upstream compiler: such as https://github.com/beef331/sumtypes for variables with sum types or pattern matching libs like https://andreaferretti.github.io/patty/ | https://github.com/alehander92/gara.

...except that macros don't change the syntax of the language! They just offer convenience on top of it, most common example is the `=>` lambda operator from the `sugar` module. I do agree, that the pattern matching macro presented in the article is a bit hard to get used to, but you don't have to, if you don't like pattern matching. And of course there are plenty of alternatives available as well, the simplest one imo is https://github.com/andreaferretti/patty

The Lissp transpiler incrementally compiles and executes each top-level form to Python. It needs to do this in case there's a macro definition that might affect the compilation of a subsequent form. If it's only executing definitions, this is harmless, but if you want to precompile the main module, it needs the guard, or the side effects will happen too.

If you want Python to be as customizable as Lissp, check out Hissp (and Hebigo).

Python's lambdas can have as many lines as you want. Just wrap parens around it. Hissp uses this form as a compilation target. Its REPL shows the Python compilation. Play around with it til you get it: https://github.com/gilch/hissp

The original Lisp's S-expression syntax was just supposed to be an intermediate language used by the compiler when processing the real language based on M-expressions, which kind of never took off. Numerous alternatives to S-expressions have been proposed, and some retain homoiconicity, another feature diagnostic of a Lisp (and one that ECMAScript lacks). For example, see Hebigo's readme, which shows a direct correspondence between its Python-like syntax and that of Hissp's default reader (Lissp), which uses the S-expressions. Julia can also be written in S-expressions, but this usually only used in macro definitions.

I think LoL is too CL-specific. If you know both languages first, you can pretty much translate, but since they'd be trying to learn Lisp in the first place, this is a bad idea.

On the other hand, [Hissp][1] has a pretty good tutorial for anyone coming from a Python background.

[1]: https://github.com/gilch/hissp

Hebigo: a whitespaceLisp isomorphic to Hissp that looks like Python.