andre

andre

Effective Haskell: Chapter 12 - missing some code on p.438 (B9 - PDF version)

@RebeccaSkinner

Chapter 12 starts with the code for the File Archive builder from the bottom of p.438 to p.440.

If the intention was to provide the complete version built during Chapter 11, the definition of the Encode typeclass is missing.

We can find it on p.418-419, which is

class Encode a where
  encode :: a -> ByteString
  encode = BS.drop 4 .encodeWithSize
  
  encodeWithSize :: a -> ByteString
  encodeWithSize a = 
    let s = encode a
        l = fromIntegral $ BS.length s
    in word32ToByteString l <> s
    
  {-# MINIMAL encode | encodeWithSize #-}

Where Next?

Popular Pragmatic Bookshelf topics Top

yulkin
your book suggests to use Image.toByteData() to convert image to bytes, however I get the following error: "the getter ‘toByteData’ isn’t...
New
swlaschin
The book has the same “Problem space/Solution space” diagram on page 18 as is on page 17. The correct Problem/Solution space diagrams ar...
New
AndyDavis3416
@noelrappin Running the webpack dev server, I receive the following warning: ERROR in tsconfig.json TS18003: No inputs were found in c...
New
jskubick
I found an issue in Chapter 7 regarding android:backgroundTint vs app:backgroundTint. How to replicate: load chapter-7 from zipfile i...
New
mert
AWDWR 7, page 152, page 153: Hello everyone, I’m a little bit lost on the hotwire part. I didn’t fully understand it. On page 152 @rub...
New
a.zampa
@mfazio23 I’m following the indications of the book and arriver ad chapter 10, but the app cannot be compiled due to an error in the Bas...
New
davetron5000
Hello faithful readers! If you have tried to follow along in the book, you are asked to start up the dev environment via dx/build and ar...
New
dachristenson
I just bought this book to learn about Android development, and I’m already running into a major issue in Ch. 1, p. 20: “Update activity...
New
dachristenson
@mfazio23 Android Studio will not accept anything I do when trying to use the Transformations class, as described on pp. 140-141. Googl...
New
dachristenson
I’ve got to the end of Ch. 11, and the app runs, with all tabs displaying what they should – at first. After switching around between St...
New

Other popular topics Top

AstonJ
There’s a whole world of custom keycaps out there that I didn’t know existed! Check out all of our Keycaps threads here: https://forum....
New
Exadra37
I am asking for any distro that only has the bare-bones to be able to get a shell in the server and then just install the packages as we ...
New
AstonJ
If you are experiencing Rails console using 100% CPU on your dev machine, then updating your development and test gems might fix the issu...
New
AstonJ
If you get Can't find emacs in your PATH when trying to install Doom Emacs on your Mac you… just… need to install Emacs first! :lol: bre...
New
PragmaticBookshelf
Author Spotlight Jamis Buck @jamis This month, we have the pleasure of spotlighting author Jamis Buck, who has written Mazes for Prog...
New
DevotionGeo
I have always used antique keyboards like Cherry MX 1800 or Cherry MX 8100 and almost always have modified the switches in some way, like...
New
PragmaticBookshelf
Author Spotlight: Peter Ullrich @PJUllrich Data is at the core of every business, but it is useless if nobody can access and analyze ...
New
CommunityNews
A Brief Review of the Minisforum V3 AMD Tablet. Update: I have created an awesome-minisforum-v3 GitHub repository to list information fo...
New
Margaret
Ask Me Anything with Mark Volkmann @mvolkmann On February 24 and 25, we are giving you a chance to ask questions of PragProg author M...
New
RobertRichards
Hair Salon Games for Girls Fun Girls Hair Saloon game is mainly developed for kids. This game allows users to select virtual avatars to ...
New

Sub Categories: