tssm / up-to-date-real-world-haskell Goto Github PK

On the readme, it sounds like several chapters are in the todo / started status. But I'm not sure if the readme is still current.

Sorry, I didn't know how else to contact you. It would be great if there was a way to contribute. I for one, am interested. :-)

Perhaps the chapter on exceptions can talk about async exceptions? cf. https://tech.fpcomplete.com/haskell/tutorial/exceptions

I follow the codes in chapter 14 and find some little problems.

1. charClass_wordy defined but not used, I think maybe the charClass function should be modified as following:

charClass (']':cs) = (']':) <$> globToRegex' cs
charClass (c:cs) = (c:) <$> charClass_wordy cs

2. According to monad fail, from GHC 8.8+, the fail function will not be supported. I suggest change the fail function to error or other implementation.

3. charClass_wordy also lacks a matching form, which should be added as follows:

charClassWordy "" = 
    error "No more input"

This is from Chapter 1, "Getting Started":

ghci> 7 ^ 80
40536215597144386832065866109016673800875222251012083746192454448001
it :: Integer

But with latest ghc, we get:

ghci> 7 ^ 80
40536215597144386832065866109016673800875222251012083746192454448001
it :: Num a => a

I couldn't figure out how to rewrite that section and also preserve the lesson about Integer.

Lets track it here for now.

Here is how. This means I should add the source files somewhere.

• Explain DerivingVia instead of GeneralizedNewtypeDeriving
• Remove Functor and Applicative instances boilerplate

In: https://github.com/tssm/up-to-date-real-world-haskell/blob/master/1-getting-started.org#getting-started-with-ghci-the-interpreter

• Fix snake_case identifiers
• Use CamelCase for all filenames
• Use point-free style whenever possible after it is explained
• Use 2 spaces for indentation

https://www.oreilly.com/catalog/errata.csp?isbn=9780596514983

in the description of splitFileName:

But in chapter 8, here describe it:

And when I run it in the ghci:

could it be update?

In "Chapter 6: Using Type Classes" at "The dreaded monomorphism restriction" it states that the following code results in an error.

myShow = show

But in ghci I get no error

GHCi, version 8.10.2: https://www.haskell.org/ghc/  :? for help
Prelude> myShow = show
Prelude>

I think this is a great effort / project.

I am sure I'm not the only one who would be willing to sponsor the project monetarily. And I'm sure some folks would even be willing to play a more active role in the development of the updated book.

In https://github.com/tssm/up-to-date-real-world-haskell/blob/master/23-gui-programming-with-gtk2hs.org#installing-gtk2hs

That is all ❤️

Hi,
I was reading Chapter 6: Using Type Classes. I found several lines missing (for the declaration of UniqueId was unclear):

However, as I looked into the source, these lines are still there:

#+BEGIN_NOTE
The type and newtype keywords

Although their names are similar, the ~type~ and ~newtype~
keywords have different purposes. The ~type~ keyword gives us
another way of referring to a type, like a nickname for a friend.
Both we and the compiler know that ~[Char]~ and ~String~ names
refer to the same type.

In contrast, the ~newtype~ keyword exists to /hide/ the nature of
a type. Consider a ~UniqueID~ type.

#+CAPTION: Newtype.hs
#+BEGIN_SRC haskell
newtype UniqueID = UniqueID Int
    deriving (Eq)
#+END_SRC

The compiler treats ~UniqueID~ as a different type from ~Int~. As
a user of a ~UniqueID~, we know only that we have a unique
identifier; we cannot see that it is implemented as an ~Int~.
#+END_NOTE

Perhaps this is a problem, but I am not sure at which level it arises.