learning-scalaz | source for learning Scalaz
kandi X-RAY | learning-scalaz Summary
kandi X-RAY | learning-scalaz Summary
source for learning Scalaz.
Support
Quality
Security
License
Reuse
Top functions reviewed by kandi - BETA
Currently covering the most popular Java, JavaScript and Python libraries. See a Sample of learning-scalaz
learning-scalaz Key Features
learning-scalaz Examples and Code Snippets
Community Discussions
Trending Discussions on learning-scalaz
QUESTION
To learn how to create monads and to learn their internal mechanisms I am trying to implement a version of Writer following this awsome article: You Could Have Invented Monads!
The problem I'm facing is that I can't use the data structures I created in a for comprehension.
This is a cleaned extract of my code:
...ANSWER
Answered 2018-Sep-14 at 18:02Here is how you can force it to compile:
QUESTION
I'm reading about scalaz and noticed that we can make a list of Applicative
s to be an Applicative
of List
.
ANSWER
Answered 2018-Mar-03 at 19:29This is possible if the F
in question is Traversable
. The code you're showing is specialized for List
, but in fact it holds for all Traversable
functors.
This means, that for every F
that's Traversable
and any G
that's Applicative
, we can go from F[G[A]]
to G[F[A]]
with sequence
.
List
also has an Applicative
, so we can use it as our G
, whereas in your example List
was used as the F
, the Traversable
functor.
An example where what you're asking works could be Option
. Here's the original direction:
QUESTION
I'm reading ScalaZ tutorial and now I'm on the section of Yes-No type class. Eventual goal is to get 1.truthy
to return true
. Here is the implementation of the typeclass:
ANSWER
Answered 2017-Nov-26 at 04:32I think the problem here is a misreading of the scope of this sentence:
Eventual goal is to get
1.truthy
to returntrue
.
This is what we're trying to do with the CanTruthyOps
stuff, but it's not the goal of the CanTruthy
type class, and more generally syntactic concerns like this aren't the goal of type classes.
The goal of type classes is to allow us to constrain types in a simple, flexible, compositional way. The type parameter-less CanTruthy
approach doesn't really support the simple part or the flexible part or the compositional part very nicely (arguably the implementation of type classes in Scala isn't very simple either, but it's at least a little simpler and definitely more flexible and compositional).
Take this method from the tutorial, for example (lightly modified to avoid the Any
):
QUESTION
I'm reading some articles about ScalaZ
and have a question about understanding it. In this article, we generalize the sum function, to abstract away the type to be summed.
ANSWER
Answered 2017-Nov-16 at 20:48Applicative functor is a type class with two operations: A => F[A]
and F[A => B] => F[A] => F[B]
. None of operations you mentioned has such signature. FoldLeft
is more like Foldable. It's a different type class, a parent of Traversable (aka Traverse
). And Traversable
is connected with Applicative
.
QUESTION
When i try to use Lens.lensu
from scalaz.7.2.15
, (i check http://eed3si9n.com/learning-scalaz/Lens.html)
ANSWER
Answered 2017-Oct-05 at 19:06You can read <=<
as "after". Then
Community Discussions, Code Snippets contain sources that include Stack Exchange Network
Vulnerabilities
No vulnerabilities reported
Install learning-scalaz
Support
Reuse Trending Solutions
Find, review, and download reusable Libraries, Code Snippets, Cloud APIs from over 650 million Knowledge Items
Find more librariesStay Updated
Subscribe to our newsletter for trending solutions and developer bootcamps
Share this Page