Regular Expressions
One of the unsung successes in standardization of computer science has been the
Regular Expressions (RE), a language for specifying text search strings.
This practical language is in every computer language, word processor, and
text processing tools like the Unix’s grep.
🏆 A regular expression is an algebraic notation for characterizing a set of strings.
They are particularly useful for searching in texts, when we have a pattern to search for
and a corpus of texts to search through.
A regex search function will search through the corpus returning all texts that match the pattern.
The corpus can be a single document or a collection.
For example, the Unix cmd tool grep takes a regex and
returns every line of the input document that matches the pattern in regex.
🚨 RegEx comes in many variants. In this article we will be discussing extended regex.