How can you make a coding language?

Question

I have seen code that said language is Jack. I can’t program with that Language.
How can you make one?

https://code.sololearn.com/W3reVwBPq253/?ref=app

Answer 1

It's just about parsing text. And there's a quite big difference between a new programming language and parsing some text to execute it using another language.

Answer 2

how do you make code run with language?