I am currently reading Learn You a Haskell for Great Good! and am stumbling on the explanation for the evaluation of a certain code block. I've read the explanations several times and am starting to doubt if even the author understands what this piece of code is doing.
I've just started to learn Racket.I have this code:(car l1) returns 1. (cdr l1) returns '(2 3 4)Is there a function that returns '(1 2 3)?
I encountered this example while reading Learn You a Haskell for Great Good.I don't quite see how to treat $ as function application. Does that mean $ is an operator? But if so, how it will be nested with + or * in the example? I tried $ 3 4+,...
The example is taken from a "Haskell programming from first principles" The goal of filter function is get rid of all the objects except those of 'DbDate' type.
I have a piece of code like this:At the moment I'm throwing an exception when the given Object is not present.
I'm trying to use reduce() combine a set of arrays in a "collated" order so items with similar indexes are together. For example:
Is there an elegant way to convert a Map<P, Optional<Q>> to a sparse Map<P, Q> ?This should work, but it's a bit meh:
I am new to Java, kinda transition from C# to Java. java.util.function has a interface defined as Function which is input to computeIfAbsent method of Map.
I'm learning about monads in Haskell, I understood why they are useful, I understood in general what bind, join, return do.
I have a game , user vs computer and I want to randomly choose who starts the game. I have This gets a random number 0 or 1. However it is a IO Int, so I can't have an if statement comparing it to a number like