higher-order-functions

问题 I am trying to understand functional programming from first principles, yet I am stuck on the interface between the pure functional world and the impure real world that has state and side effects. From a mathematical perspective, what is a function that returns a function? what is a function that returns an IO action (like Haskell's IO type)? To elaborate: In my understanding, a pure function is a map from domain to co-domain. Ultimately, it is a map from some values in computer memory to

问题 I would like to define implicit value in a wrapper function and make it available to inner function, so far I managed to do that by passing implicit variable from wrapper: case class B() trait Helper { def withImplicit[A]()(block: => A): A = { implicit val b: B = B() block } } class Test extends Helper { def useImplicit()(implicit b: B): Unit = {...} def test = { withImplicit() { implicit b: B => useImplicit() } } } Is it possible to avoid implicit b: B => and make implicit val b: B = B()

来源： https://stackoverflow.com/questions/47208569/typescript-function-overloads-with-generic-optional-parameters

来源： https://stackoverflow.com/questions/47208569/typescript-function-overloads-with-generic-optional-parameters

来源： https://stackoverflow.com/questions/44427382/what-does-mean-in-kotlin

来源： https://stackoverflow.com/questions/63295758/trying-to-understanding-why-this-function-using-foldr-in-haskell-isnt-working

问题 I have an array of objects like this input, and I want to nest some objects inside another objects (based if their parentId is the parents' forumId), I got the function working but up to 1 depth, how can I get it working for n depth? Any idea or optimizations are appreciated! EDIT: After pointing out, the input isn't necessarily ordered. const input = [ { forumId: 1, parentId: null, forumName: "Main", forumDescription: "", forumLocked: false, forumDisplay: true, }, { forumId: 2, parentId: 1,

问题 Consider the following function, which returns all the unique permutations of a set of elements: def get_permutations(elements): if len(elements) == 0: yield () else: unique_elements = set(elements) for first_element in unique_elements: remaining_elements = list(elements) remaining_elements.remove(first_element) for subpermutation in get_permutations(tuple(remaining_elements)): yield (first_element,) + subpermutation for permutation in get_permutations((1, 1, 2)): print(permutation) This

问题 Consider the following function, which returns all the unique permutations of a set of elements: def get_permutations(elements): if len(elements) == 0: yield () else: unique_elements = set(elements) for first_element in unique_elements: remaining_elements = list(elements) remaining_elements.remove(first_element) for subpermutation in get_permutations(tuple(remaining_elements)): yield (first_element,) + subpermutation for permutation in get_permutations((1, 1, 2)): print(permutation) This

问题 I'm looking for a way to use a function as an argument to another function in GLSL. In regular C, it can be simulated by passing a function pointer as a function argument. It also seems that other languages (like HLSL) now provide ways to deal with high-level constructs like higher-order functions, or can simulate them with clever use of HLSL structures. unfortunately I'm stuck with GLSL for now, and I can't find any way to simulate higher-order functions. Is it really impossible in current