functional-programming

问题 I want to implement a meta-circular evaluator in JS with support to functional programming. How can I parse this? [1..10] I want to receive 1 and 10 回答1: This is a basic implementation of generating a range. The goal you are talking about is going to be too complex for regex (firmly tongue in cheek). Using tagged template literal syntax. Regex finds two digit sequences, converts to numbers. Fills an array. range = (str,...args) => (([,min,max])=> Array(Math.abs(max-min)+1).fill(+min).map((_,i

问题 I have a Spring Boot 2, reactive webflux web service, which persists uploaded, multipart fileparts to MongoDB's GridFS. This is working properly. Today, a request was made to include metadata for the files being added to GridFS. Unfortunately, I have not been able to get it to work with my functional/non-annotated web service. I would appreciate any suggestions or nudges in the correct direction. Here are the details: An example of the request being sent to my endpoint: curl -X "POST" "http:/

问题 I'm trying to compile an Agda file, but I'm having trouble getting it to find the standard library. I've seen the documentation here. I've used Stack to install it: > which agda /home/joey/.local/bin/agda And I've set the environment variable for my Agda directory: > echo $AGDA_DIR /home/joey/.agda Which is populated with the correct files: /home/joey/agda/agda-stdlib/standard-library.agda-lib > cat "$AGDA_DIR"/libraries /home/joey/agda/agda-stdlib/standard-library.agda-lib > cat "$AGDA_DIR"

问题 This question already has answers here : Filter object properties by key in ES6 (24 answers) Closed last year . This is my object (made sure it's a typeof object): { "1": {"user_id":1,"test":"","user_name":"potato0","isok":"true"}, "2":{"user_id":2,"test":"","user_name":"potato1","isok":" true"}, "3":{"user_id":3,"test":"","user_name":"potato2","isok":" true"}, "4":{"user_id":4,"test":"","user_name":"potato3","isok":"locationd"} } Why using .filter doesn't work for me? Is it because my

问题 I am working on a complex logic where I need to redistribute a quantity from one dataset to another dataset. In the example we have Owner and Invoice - We need to subtract the quantity from the Invoice to the exact Owner match (at a given postal code for a given car). The subtracted quantity needs to be redistributed back to the other postal code where the same car appears. The complexity happens where we should avoid distributing to postal code where the same car is present in the Invoice

问题 I'm trying to find separate the duplicates and non-duplicates in a List by adding them to a Set and List while using Stream.filter and Stream.map List<String> strings = Arrays.asList("foo", "bar", "foo", "baz", "foo", "bar"); Set<String> distinct = new HashSet<>(); List<String> extras = new ArrayList<>(); strings .stream() .filter(x -> !distinct.add(x)) .map(extra -> extras.add(extra)); At the end of this, I expect distinct to be [foo, bar, baz] and extras to be [foo, foo, bar] , since there

问题 With the following dataset: import pandas as pd df = pd.DataFrame({'Date':['26-12-2018','26-12-2018','27-12-2018','27-12-2018','28-12-2018','28-12-2018'], 'In':['A','B','D','Z','Q','E'], 'Out' : ['Z', 'D', 'F', 'H', 'Z', 'A'], 'Score_in' : ['6', '2', '1', '0', '1', '3'], 'Score_out' : ['2','3','0', '1','1','3'], 'Place' : ['One','Two','Four', 'Two','Two','One']}) I would like to code groupby rules on a generic form in order to try parameterizing subsets creation. For instance, instead of the

问题 With the following dataset: import pandas as pd df = pd.DataFrame({'Date':['26-12-2018','26-12-2018','27-12-2018','27-12-2018','28-12-2018','28-12-2018'], 'In':['A','B','D','Z','Q','E'], 'Out' : ['Z', 'D', 'F', 'H', 'Z', 'A'], 'Score_in' : ['6', '2', '1', '0', '1', '3'], 'Score_out' : ['2','3','0', '1','1','3'], 'Place' : ['One','Two','Four', 'Two','Two','One']}) I would like to code groupby rules on a generic form in order to try parameterizing subsets creation. For instance, instead of the

问题 With the following dataset: import pandas as pd df = pd.DataFrame({'Date':['26-12-2018','26-12-2018','27-12-2018','27-12-2018','28-12-2018','28-12-2018'], 'In':['A','B','D','Z','Q','E'], 'Out' : ['Z', 'D', 'F', 'H', 'Z', 'A'], 'Score_in' : ['6', '2', '1', '0', '1', '3'], 'Score_out' : ['2','3','0', '1','1','3'], 'Place' : ['One','Two','Four', 'Two','Two','One']}) I would like to code groupby rules on a generic form in order to try parameterizing subsets creation. For instance, instead of the

问题 Is there any function in ramda how can I find key by nested key value? I found a way how to find an object in array but that doesn't help. I need something like this: const obj = { addCompany: { mutationId: '1' }, addUser: { mutationId: '2' }, addCompany: { mutationId: '3' } } const findByMutationId = R.??? findByMutationId('2', obj) // returns addUser 回答1: find combined with propEq and keys should work const obj = { addCompany: { mutationId: '1' }, addUser: { mutationId: '2' }, addCompany2: