functional-programming

问题 I wish to call OCaml code through C++ by compiling OCaml to a static or shared library that contains a C interface. This page seems to explain how to create a C interface for OCaml. But how do I do it and compile it? And how do I obtain the .h file to load in my C++ code? Also, could someone explain to be this part: The OCaml runtime system comprises three main parts: the bytecode interpreter, the memory manager, and a set of C functions that implement the primitive operations. Some bytecode

问题 I am trying to write a method that can take in a String classname and a String value, and return the value represented as that String. Example inputs: parse("java.lang.String", "abc") -> String "ABC" parse("java.lang.Boolean", "FALSE") -> Boolean FALSE parse("java.lang.Integer", "123") -> Integer 123 parse("com.me.Color", "RED") -> enum Color.RED I have found that if I use an if block containing assignableFrom calls, I can achieve this. But would prefer writing something more extendable, so

问题 This question already has answers here : Is this casting in golang? (1 answer) What is the meaning of “dot parenthesis” syntax in Golang? (1 answer) Closed 2 years ago . I recently started looking for functional go examples and I found this function: mapper := func (i interface{}) interface{} { return strings.ToUpper(i.(string)) } Map(mapper, New(“milu”, “rantanplan”)) //[“MILU”, “RANTANPLAN”] Now in this function, as you can see the return value of mapper is: strings.ToUpper(i.(string)) .

问题 This question already has answers here : Is this casting in golang? (1 answer) What is the meaning of “dot parenthesis” syntax in Golang? (1 answer) Closed 2 years ago . I recently started looking for functional go examples and I found this function: mapper := func (i interface{}) interface{} { return strings.ToUpper(i.(string)) } Map(mapper, New(“milu”, “rantanplan”)) //[“MILU”, “RANTANPLAN”] Now in this function, as you can see the return value of mapper is: strings.ToUpper(i.(string)) .

问题 This question already has answers here : Is this casting in golang? (1 answer) What is the meaning of “dot parenthesis” syntax in Golang? (1 answer) Closed 2 years ago . I recently started looking for functional go examples and I found this function: mapper := func (i interface{}) interface{} { return strings.ToUpper(i.(string)) } Map(mapper, New(“milu”, “rantanplan”)) //[“MILU”, “RANTANPLAN”] Now in this function, as you can see the return value of mapper is: strings.ToUpper(i.(string)) .

问题 Code speaks better than language, so: ['a', 'b', 'c'].reduce((accumulator, value) => accumulator.concat(value), []); The code is very silly and returns a copied Array... TS complains on concat's argument: TS2345: Argument of type 'string' is not assignable to parameter of type 'ConcatArray'. 回答1: I believe this is because the type for [] is inferred to be never[] , which is the type for an array that MUST be empty. You can use a type cast to address this: ['a', 'b', 'c'].reduce((accumulator,

问题 Haskell has Functor , Applicative and Monad instances defined for functions (specifically the partially applied type (->) a ) in the standard library, built around function composition. Understanding these instances is a nice mind-bender exercise, but my question here is about the practical uses of these instances. I'd be happy to hear about realistic scenarios where folks used these for some practical code. 回答1: A common pattern that involves Functor and Applicative instances of functions is

问题 Haskell has Functor , Applicative and Monad instances defined for functions (specifically the partially applied type (->) a ) in the standard library, built around function composition. Understanding these instances is a nice mind-bender exercise, but my question here is about the practical uses of these instances. I'd be happy to hear about realistic scenarios where folks used these for some practical code. 回答1: A common pattern that involves Functor and Applicative instances of functions is

问题 There are too much hype about functional programming and particularly the new Java 8 streams API. It is advertised as good replacement for old good loops and imperative paradigm. Indeed sometimes it could look nice and do the job well. But what about performance? E.g. here is the good article about that: Java 8: No more loops Using the loop you can do all the job with a one iteration. But with a new stream API you will chain multiple loops which make it much slower(is it right?). Look at

问题 I have two lists of nodes, who shaped like so: interface TreeNode { data: { name: string, sharedProp: boolean, oldProp: boolean }, children: TreeNode[], parents: TreeNode[], thereAreSomeShallowProps: any, } The full dataset would be an array of TreeNode What I'd like is to have a function that I can traverse down this tree, merging changes in a changes tree into the base tree. Some of the feature it'd need: Match the values of a specified key (in this case support multilevel keys), and merge