Let me explain. Suppose I want to teach Python to someone who only speaks Spanish. As you know, in most programming languages all keywords are in English. How complex would it be to create a program that will find all keywords in a given source code and translate them? Would I need to use a parser and stuff, or will a couple of regexes and string functions be enough?
If it depends on the source programming language, then Python and Javascript would be the most important.
What I mean by "how complex would it be" is that would it be enough to have a list of keywords, and parse the source code to find keywords not in quotes? Or are there enough syntactical weirdnesses that something more complicated is required?