python (12.9k questions)

javascript (9.2k questions)

reactjs (4.7k questions)

java (4.2k questions)

java (4.2k questions)

c# (3.5k questions)

c# (3.5k questions)

html (3.3k questions)

Questions - fold

Functional Programming in Kotlin: Counting elements in list by using fold

I've got the task to write a function using fold (functional programming) to count the number of elements in a list that fulfill the predicate. I was given the function signature fun <A> count(l...
test-img

Pythagorion

list

kotlin

generics

functional-programming

fold

Votes: 0

Answers: 4

Latest Answer

By saying return you return the entire count function. you can use return@fold instead. so like fun <A> count(list: List<A>, predicate: (A) -> Boolean): Int { return list.fold(0) { ...
test-img

Ivo

Question about the Foldable Maybe instance

Source: Hutton, Graham. "Programming in Haskell" (p. 267) Show how the Maybe type can be made foldable and traversable, by giving explicit definitions for fold, foldMap, foldr, foldl and t...
test-img

F. Zer

haskell

fold

Votes: 0

Answers: 1

Latest Answer

Yes, the code you're looking at is bogus and won't even compile. It should do what you said: foldr _ v Nothing = v Note that you don't really need to do all this manual work, except as an exercise. ...
test-img

dfeuer

Processing successors in dfs with Haskell

Consider the following Python function, which, given the successors of a node, visits them and collects the results. (In practice this logic would form a part of the recursive visit function.) from ty...
test-img

Eric Auld

haskell

depth-first-search

fold

Votes: 0

Answers: 1

Latest Answer

Looks pretty straightforward to translate it directly: get_successor_results :: (node_key -> discovered -> Bool) -> (node_key -> State discovered result) -> [node_key] ->...
test-img

Daniel Wagner

Posts

Questions

Blogs

Jobs