analise-léxica

I'm using the Lex generator to do a lexical analysis of a simple C++code. The following code is from the Generator: %{ ... it was an fprintf function - which writes to a file, using C, or a RETURN so I can write to the file inside the main method).

I was taking a look at the source code of a known php library, called Twig (it is a template engine, with its own syntax), an ... t things? Sorry if I'm confused on the question, but I think the community will help me with a good and enlightening answer.