When someone writes a new programming language, what do they write it IN?

Question

Please excuse my ignorance. I\'m dabbling in PHP and getting my feet wet browsing SO, and feel compelled to ask a question that I\'ve been wondering about for years:

Answer 1

Even further binary ,or assembly operations must be translated into functions, thats the assemblers/compilers job, then into object,from data and functions, if you don't have a source file to see" how these objects functionality should be represented in your language implementation ,Then you have to recognize "see" implement, or define your own functions ,procedures, and data structures, Which requires a lot of knowledge, you need to ask yourself what is a function.Your mind then becomes the language simulation.This Separate a Master programmer from the rest.