Comment by fuzztester

I've read some part of the book Real World OCaml, by Yaron Minsky and Anil Madhavapeddy.

https://dev.realworldocaml.org/

I also saw this book OCaml from the Very Beginning by John Whitington.

https://ocaml-book.com/

I have not read that one yet. But I know about the author, from having come across his PDF tools written in OCaml, called CamlPDF, earlier.

https://github.com/johnwhitington/camlpdf

>CamlPDF is an OCaml library for reading, writing and modifying PDF files. It is the basis of the "CPDF" command line tool and C/C++/Java/Python/.NET/JavaScript API, which is available at http://www.coherentpdf.com/.