I'm not sure whether what I am trying to find exists, but I am looking for free resources (standard algorithms, data structures, free online textbooks, etc.) to help implement a minimal regular expression library for use in a text-editor that I am developing.

I realize that such libraries are freely available with source code, but I would like to try to design and implement this by myself, as the purpose of the project is just for learning.

Has anyone found particularly useful online resources relating to this in the past? If so, I would greatly appreciate it if you could direct me to them.