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Category Theory For Programmers

An unofficial PDF version of "Category Theory For Programmers" by Bartosz Milewski, converted from his blogpost series (with permission!).

Category Theory for Programmers

Buy the book

Build the book

The building workflow requires Nix. After installing Nix, you need to enable the upcoming "flake" feature which must be enabled manually the time being. This is needed to expose the new Nix commands and flakes support that are hidden behind feature-flags.

Afterwards, type nix flake show in the root directory of the project to see all the available versions of this book. Then type nix build .#<edition> to build the edition you want (Haskell, Scala, OCaml, Reason and their printed versions). For example, to build the Scala edition you'll have to type nix build .#ctfp-scala.

Upon successful compilation, the PDF file will be placed in the result directory.

The command nix develop will provide a shell containing all the required dependencies to build the book manually using the provided Makefile. To build the ctfp-scala edition, just run make ctfp-scala.


Contributors are welcome to contribute to this book by sending pull-requests. Once reviewed, the changes are merged in the main branch and will be incorporated in the next release.

Note from Bartosz: I really appreciate all your contributions. You made this book much better than I could have imagined. Thank you!

Find the list of contributors on Github.


PDF LaTeX source and the tools to create it are based on the work by Andres Raba. The book content is taken, with permission, from Bartosz Milewski's blogpost series, and adapted to the LaTeX format.

The original blog post acknowledgments by Bartosz are consolidated in the Acknowledgments page at the end of the book.


The PDF book, .tex files, and associated images and figures in directories src/fig and src/content are licensed under Creative Commons Attribution-ShareAlike 4.0 International License.

The script files and others are licensed under GNU General Public License version 3.