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The latest version of the book is B10.0, released 4 days ago. If you've bought a PDF of the book and would like to update it to this version (for free), visit your home page.

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If you've found a new error, please submit it.

  • Typo
  • Tech. error
  • Suggestion
  • Maybe next edition
  • Not a problem
  • Reported in: B5.0 (07-Mar-18)
PDF page: 10
This is just a suggestion. I suggest that you add the chapter number to the folder name of the code. Like this. 01-get-started/elm-files/Main01.elm...more...
  • Reported in: B8.0 (18-Sep-18)
PDF page: 20
Something in the behaviour of the elm compiler may have changed. The book says "elm make src/Picshare.elm" - This command will compile "Picshare.elm" ...more...
  • Reported in: B9.0 (21-Sep-18)
PDF page: 20
My earlier erratum report was incomplete (but there isn't any way to edit it) On page 20, one is actually told to "elm make src/Picshare.elm --outp...more...
  • Reported in: B9.0 (21-Sep-18)
PDF page: 21
"Elm.Picshare.embed is not function" When one uses the provided "embedding HTML" for the picshare application, which pulls in the picshare.js, then...more...
  • Reported in: B7.0 (28-Jul-18)
Paper page: 22

The code example on this page is displaying the comment marks at the end of the highlighted/numbered lines.--Steve Rowley

  • Reported in: B8.0 (08-Sep-18)
PDF page: 27
Paper page: 26
Second paragraph of Chapter 2, last sentence: "Along the way, we’ll learn about records, union types, and immutability, which are all important pi...more...
  • Reported in: B9.0 (21-Sep-18)
PDF page: 36
I would suggest introducing type aliases already on page 36 to describe the Model. type alias PhotoRecord = { url : String, caption : String, like...more...
  • Reported in: B9.0 (21-Sep-18)
PDF page: 36
Further to my suggestion to introduce type aliases on 36, also introduce the union type for Msg at once. Both together allow one to immediately make t...more...
  • Reported in: B9.0 (04-Oct-18)
PDF page: 50
I feel that the refactored "viewLoveButton" is a bit "smelly" because deep down in the div tree, the instance "ToggleLike" comes a bit out of nowhere....more...
  • Reported in: B9.0 (04-Oct-18)
PDF page: 51
I suggest to hand developer a tool: logging to the browser's logging console, and this very early. It's more fun when you see what's going on. Elm ...more...
  • Reported in: B9.0 (04-Oct-18)
PDF page: 53
viewCommentList comments = case comments of [] -> text "" _ -> ...more...
  • Reported in: B9.0 (04-Oct-18)
PDF page: 57
In "viewComments", the SaveComment and UpdateComment constructors are hardcoded-in. If one tries to softcode them (i.e. pass them in from the calle...more...
  • Reported in: B9.0 (04-Oct-18)
PDF page: 59
In case an "only whitespace" comment is submitted (which is possible as "only whitespace" still enables the "save button"), one might want to reset th...more...
  • Reported in: B7.0 (30-Jun-18)
PDF page: 240
Hello there I managed to get completely different numbers by using Firefox (v61). For example: fold and map vs foldMap; foldMap is a little m...more...
Jeremy Fairbank says: I do mention the browser and version I'm using, but it may still be worth mentioning that other browsers might yield totally different results. It's tricky with this kind of chapter.