higher-order-functions

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

问题 How can I create a reusable module for iteration which allows me to: choose whether it iterates in parallel lets me specify a higher-order function of which tasks need to be performed Here are some dummy functions. They for itself pose the second part of the question: Should I have an interface here that each of these functions at least implements the parameter inputDay:String ? or is it better to have a generic function with a configuration class, where the configuration implements a minimal

问题 LIVE CODE EXAMPLE: Background: Trying to learn javascript's higher order function, some redux theory and applying it through a data transformations example and have been failing for the last few hours. :( Question: How can I iterate over the approved1 or approved2 and return a new object bases on 2 cases . Furthermore, is there a way to do this with a higher order function like Array.reduce() or a combination baked in higher order functions? Lastly , if the final Object is wrapped in an array

问题 How can I create map, a higher order function, in Red language. It should take a block and a function as arguments and apply the sent function to each member of block. I tried following code: Red [] mapfn: function[blk sfn][ outblk: copy [] foreach i blk[ append outblk (sfn i) ] outblk ] ; to test: myblk: [" this " " is " " a " " line " "for" " testing " " only "] probe mapfn myblk 'reverse probe mapfn myblk 'trim But it is not working - it simply sends back the original block without

问题 I have a set of python webservices that work with data objects they get via a JSON POSTs. In my old services I have a lot of boilerplate to (de)serialize and check JSONs for each object. With Python 3.5s new typing and PEP 484 I have the feeling that could be substantially reduced. Is it worth it? Does anyone have a good solution for it? Additional info My old boilerplate looks like this for every object: class Data: class Nested1: def __init__(self, nested1_flat1): self.nested1_flat1 =

问题 I'm new to functional programming. My problem is that I have a main array and a fixed number of "destination" arrays. I would like to distribute the elements from the main array into the correct resulting array based on a certain value of each element. I'm guessing that one approach would be to have one map function that goes through the main array elements, determines the correct "destination array" value (based on some logic) and then adds the elements to that array. However, I'm not sure

问题 I have some vector vect and I want to iterate over the row vectors v of a matrix and calculate: cov(v, vect) . I tried: for(vect in mat2) #where mat2 is a 215 by 31 matrix However, each vector appeared to be a scalar with value 1. How do I iterate over the row vectors of a matrix? To make this even better, since I am interested in calculating the sum of cov(v, vect) where v is a row vector, how can I use the higher-order functions left-fold and right-fold 回答1: Are you looking for apply ?

问题 I have this simple function which returns a list of pairs with the adjacents elements of a list. adjacents :: [a] -> [(a,a)] adjacents (x:y:xs) = [(x,y)] ++ adjacents (y:xs) adjacents (x:xs) = [] I'm having problems trying to write adjacents using foldr . I've done some research but nothing seems to give me a hint. How can it be done? 回答1: Tricky folds like this one can often be solved by having the fold build up a function rather than try to build the result directly. adjacents :: [a] -> [(a

问题 Supposedly I have a method that has one default parameter. I want to pass it as an argument to another method. How do I call the passed-in method with its default parameter ? def printNum(i: Int = 4): Unit = { println(i) } def doStuff(printFunc: (Int) => Unit): Unit = { // How to call printFunc with its default parameter printFunc() } doStuff(printNum) 回答1: I am afraid you cannot. Default parameter is property of methods, just like named arguments and things like this. When you pass it as a

问题 Supposedly I have a method that has one default parameter. I want to pass it as an argument to another method. How do I call the passed-in method with its default parameter ? def printNum(i: Int = 4): Unit = { println(i) } def doStuff(printFunc: (Int) => Unit): Unit = { // How to call printFunc with its default parameter printFunc() } doStuff(printNum) 回答1: I am afraid you cannot. Default parameter is property of methods, just like named arguments and things like this. When you pass it as a