Is there a meta text processing concept in CS?
You should look into Theory of Automata, Languages and Computation:
These are the theoretical foundations of scanning, parsing and processing text (and furthermore constructing formal languages and grammars).

Components of the theory, are, for example:


Pushdown automaton
Context free grammars
Parsing techniques such as recursive decent, LL or SLR parsing.




Classical introductory textbook on this subject is "Introduction To Automata Theory, Languages, and Computation" by John E. Hopcroft,Rajeev Motwani and Jeffrey D.Ullman.