Text analysis algorithms

Question

Algorithms

Good day.
I am interested in text analysis algorithms. Maybe someone will suggest something.

For example:
1) Analysis of text for similarity with other text
2) Analysis of certain occurrences for similarity (Example java, java script, javascript - according to the idea of ​​​​javascript = java script, and java! = java script) you can of course use the Levenshtein distance, but you can, there are specialized algorithms

Well, if there is any other literature on text analysis, share it.
Thank you.

Answer 1

1) Shingles won't fit?