Speeding Through Haskell: With Example Code by Mihai-Radu Popescu.
A work in progress (at 87 pages) with a breezy writing style and lots of examples.
Only available in PDF format.
Unfortunate because adding your own notes as you work through the examples would make it more valuable to you. There would be the issue of migrating your notes to a later version, a problem that remains after 20+ years of markup.
The download page is in Spanish but the text is in English.
Either download link returns the same content, one as a .zip file containing the PDF file and the other as a PDF file.
How would you solve the note migration issue?
I first saw this in a tweet by CompSciFact.