Difference between fold and foldLeft or foldRight?
fold() does parallel processing so does not guarantee the processing order. where as foldLeft and foldRight process the items in sequentially for left to right (in case of foldLeft) or right to left (in …
How does foldLeft in Scala work on DataFrame? - Stack Overflow
Aug 26, 2018 · After failing to understand how to apply it on my dataFrame, I finally I came across a method in Scala which is foldLeft which helped in fulfilling the requirement. I understand how …
scala - Fold and foldLeft method difference - Stack Overflow
Jul 4, 2012 · def fold[A1 >: A](z: A1)(op: (A1, A1) => A1): A1 = foldLeft(z)(op) So basically, fold is an implementation of foldleft with a constraint on the output type. We can now see that z will in …
scala - Reduce, fold or scan (Left/Right)? - Stack Overflow
Jul 1, 2013 · In the particular case of Scala lists, that way consists on reversing the List to then apply foldLeft. Other collections may implement different strategies. In general, if foldLeft and …
Scala: How to interpret foldLeft - Stack Overflow
Mar 27, 2022 · Does not foldLeft accumulate value that was earlier? I was expecting the result to be, Plain Donut , Plain Strawberry Donut , Strawberry Glazed Donut Second example: def …
Scala foldLeft on Maps - Stack Overflow
Dec 15, 2010 · 1 - far from clear, it is misleading seen that you exchange folded object with its result; 'folding' implies action on the collection, and so y is starting value and yy is is the result …
Difference between reduce and foldLeft/fold in functional …
Aug 6, 2014 · The functionality of foldLeft is a greater than the functionality of reduce. But you cannot parallelize a foldLeft , so its runtime is always O(N) (even if you feed in a commutative …
Output a dataframe using foldLeft on an existing dataframe
Apr 22, 2019 · Here is the skeletal code I have that implements foldLeft but it might not be the right way. def ourMethod ...
What is the 'pythonic' equivalent to the 'fold' function from ...
Starting Python 3.8, and the introduction of assignment expressions (PEP 572) (:= operator), which gives the possibility to name the result of an expression, we can use a list …
Equivalent of Scala's foldLeft in Java 8 - Stack Overflow
What is the equivalent of of Scala's great foldLeft in Java 8?. I was tempted to think it was reduce, but reduce has to return something of identical type to what it reduces on.