Ok this is nice but you this would be rougly the same in Lisp, apart from AST constructors ("newIdentNode()",...), which would simply be backquote/unquote. Plus you have to write enumInfo[0], enumInfo[1] instead of pattern matching.

And if I wanted to make 'for' into a valid variable name, or change the tokens for specifying numbers, for example, how would I go about doing that?

Easily. The macro gets handed the ast of the input. It can interpret it however it wants. There are no reserved words or anything like that. Much of nim is implemented as macros, just like most lisps

The lisp macros run before the AST exists.