Regular expressions are very commonly used to process and validate text data. Unfortunately, they suffer from various limitations. I will discuss the limitations and illustrate how using grammars instead can be an improvement. I will make the examples oncrete using parsing libraries in a couple of representative languages, although the ideas are language-independent.
I will emphasize ease of use, since one reason for the overuse of regular expressions is that they are so easy to pull out of one's toolbox.