Vlad Ardelean’s Reviews > Real World Haskell > Status Update

Chapter 9 shows a nice example of a piece of code written at the beginner level, vs the same code written by a more advanced hasketier. Nice to know!

Interesting little function: flip

r = \x -> f x arg

is equiv. to

r = flip f arg

...same thing, less readable XD

The author's ubiquitous anecdotes about how lots of bugs are caused by side-effects and how haskell provides out-of-the-box parallelism are extremely annoying.
Feels like he's trying to convert children to his religion.
Then again book is called "real world haskell, code you can believe in", so I should have expected religious fanaticism here...of which there is plenty. Too bad he's treating the topic anecdotically.

Haskell design pattern:
When creating new types (newtype/data), DO NOT export the data constructors.

Export:
1. The type constructor
2. A function which creates data of that type (frim more basic types)
3. A function which turns our data back to something more basic (strings/lists/ints/etc)

As such, clients using our type can't start poking in its internals, and updates can't break their code. Less breakage surface

Ok, so this is a function writte in "point-free" style.
func = f1 . f2 . f3

...lots of "points" there! Doesn't look too free of points XD
JK, "point-free" meams "no reference to the data. "Point" is supposed to stand for "data point"

good tutorial for converting recursive functions to folds

http://www.cs.nott.ac.uk/~gmh/fold.pdf

In the book, the topic of zip-ing with any number of lists is mentioned. Same in LYAHFGG.

This article mentions functions with any number of params. Very very hard to figure out:

https://wiki.haskell.org/Varargs

...still not the same as zip-ing, but interesting!

There'a a compiler flag to warn against non-exhaustive patterns in function definitions! Nice! Had the problem a few times, was wondering about it.

Haskell has curly braces! One could use those instead of indentation.
Good to know!

Oh no, scratch the last comment. Algebraic data types are "haskell data types"... ok, got it!