I tested out your programming language and really liked the overall grammar. I especially liked the feature of setting variables to function results.  Two things: 

1: You should add some documentation for the language as I was very confused on what I was doing at first(I solved it because I have a lot of experience in programming but for a beginner they may have trouble figuring out what to do after download and running the script). 

2: You should fix the while loop. Currently I try to use it and I don't know how and I also don't know why this keeps happening: 
Hope you can fix these issues and if you ever want some help on it, I can do so.