Well, if this particular compiler is defined in 4 functions, why couldn't it be made out of more functions, enhancing the readability and maintainability of the code?
I honestly think this is ridiculous. Sure, this is an incredible feat, and congrats. But serioulsy, I would be ashamed to publish such unreadable code under my name.
What about naming your variables with descriptive names?
What about extracting complex conditions into well named function to understand what is going on (thus defeating the purpose of the "4 functions") ?
This list could go on forever...
Writing software is not a contest for who can write the most amount of code in the most cryptic way.