Questions tagged [visitor-pattern]
The visitor design pattern is a way of separating an algorithm from an object structure on which it operates. A practical result of this separation is the ability to add new operations to existing object structures without modifying those structures.
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Visitor Pattern to handle human and AI responses
Let's suppose there is a method of an Inputter class that queries many questions. The Human inputter would have to answer all ...
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C++: Visit Any Type Holding Other Types (`std::any`, `std::variant`, etc.)
Intro
I want to visit the value held by a class, which could be of multiple types. This class is very similar to a std::any, so I will be using this in this ...
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visit for std::any
While solving an online excersise I have written some basic implementation for a visit function that works with std::any.
The ...
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Refactor typescript long switch case that run different code in according to property value
I have a typescript function that executes an array of actions on a given string value. This is the code:
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Collider class using some kind of visitor pattern
I'm trying to create a Collider class which will process collisions between different classes of the same base. One restriction is that I want these classes know nothing about each other, now they ...
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Replacing type-check with Visitor in Immutable Event-Sourced Aggregate
In my previous question, one of the answers mentioned that I shouldn't be changing behavior based on the Event class
The whole point of classing is that you can get result without having to decide ...
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Create 'classical' visitor from lambdas
I've watched a talk by Fedor Pikus on design patterns held at CppCon 2019. Motivated by this, I wrote my own visitor implementation and some helpers which allow me to create a visitor from a couple of ...
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Visitor pattern, Extensible visitor for custom implementation
I'm writing my own expression tree system, just for fun, but I have a few doubts about my code.
My goal here is to create an abstract layer of expressions, and allow different "languages" to ...
Eden Yashar
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Generic Visitor pattern library for polymorphic virtual class hierarchies
Inspired by this cppcon talk from Fedor Pikus about design patterns and some real-world need I implemented a library that allows the user to add a generic visitor pattern capabilities to class ...
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Mapping an object tree to another object tree
Programming to an interface is a design principle that enhances the flexibility of software by hiding implementation details. Consider an object tree that only exposes an interface, but you want to ...
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Calculating the average of all nodes in a Binary Search Tree using visitors
I'm required to calculate the average value of all nodes in a BST using a Visitor, I'm not sure if I did this correctly or if i could just calculate the average ...
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Iterate through Expression Tree
I'm trying to build an iterator (enumerator) that can select specific elements in an Expression tree by traversing the tree and deferring further iteration until ...
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Recursively look up directories, (a little bit) slow
I wrote some Java code to look up all files in a chosen directory (like it's showing in the Windows Explorer), and to display the results, but it seems to be slow. Can you tell me, how to speed up it?
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BST traverse as higher order function [closed]
Consider the following function to traverse a BST
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AST Visitor Pattern in Java
I am trying to make a simple expression evaluator in Java using Jacc (a parser generator). I am done with the AST creation and now need to create an evaluator. For this I made a simple test to try to ...
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Chaining JSON transformations with visitors
I have currently two use-cases that require JSON transformations before it can be deserialized.
The first use-case requires changing the custom short type property name from ...
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Visitor design pattern used for an asteroid game
Please review my code below. I am studying the Visitor Design Pattern and I think I have implemented it correctly. Please check. I have tried to split the method definitions and the prototypes as much ...
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Inline visitor implementation for C++11
I've been looking at getting back into C++11 after a few years and came across the idea of implementing the 'inline' visitor pattern. The idea is that you can specify your visitor class locally in the ...
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Golang visitor pattern for marshaling shapes as JSON, and XML
I was trying to implement visitor pattern in Golang, and came across an idea of using a generic func type instead if interface ...
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Visit each HTML element and apply inline CSS
I need to apply some css styles to an IMarkupElement. The generated HTML is only for emails so all styles are inline styles and the selectors are very simple, just ...
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A KenKen puzzle/solver in Python
I've written a simple KenKen puzzle/solver in Python. I'd love some feedback on the design of the puzzle, as well as the architecture for the solver.
To model the puzzle, I have the following classes:...
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Java sequential BFS
I am currently working on optimizing my code. In order to do that, I have to make sure that my sequential BFS works perfectly. Then, I should I apply threads or executor service to run it in parallel. ...
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C++ generic double-dispatcher/visitor
I'm trying to reduce the boilerplate code for the visitor/double dispatcher pattern. First I've created a way to enforce the dispatcher to declare the dispatch(T) function for every type supported and ...
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Modular Visitor Pattern
Motivation
I created this because the Visitor pattern felt like the most appropriate, but I also wanted to satisfy the Open/Closed principle with respect to the logic when visiting specific node ...
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Visitor that changes the structure of the objects it visits
Brief summary:
The vanilla GoF visitor is great for altering items within a tree of elements, but when the visitor visits an element it can only change the children of that element not the element ...
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Visitor Pattern/Leaky Bucket variant implementation to run an operation at a certain interval
My code is a variant on the Visitor Pattern and a "leaky bucket" variant. The goal is pretty straightforward: the "bucket" will collect a specified number of items (say, for example, 500) and then ...
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Using the visitor pattern to compose notifications
I'm solving the following problem using the Visitor design pattern in Swift:
When a quote is requested or an appointment is booked we send out an
email to the customer, and build an internal ...
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Implementation of the visitor pattern
I tried implementing visitor patter and have questions about my usage of is and as keywords. Is there a big performance hit when ...
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Chess board representation in Java
I'm currently working on a small chess game written in Java (on GitHub). The board is modeled as a Board object with a 2D array of Piece objects :
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Visitor pattern in C++
I have just implemented a quick test of the visitor design pattern in C++ and have a few questions regarding the code.
main.cpp
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