Questions tagged [iterator]
An iterator is an object-oriented programming pattern which for the most part functions similarly to a pointer to an object inside a collection with the added ability to traverse through the collection in a defined manner, agnostic of the actual implementation or even object addresses in physical memory. Iterators may be further limited in particular traversal directions.
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IndexTupleIterator.java: an iterator that generates index tuples in lexicographic order, Take IV
(See the previous iteration here.)
This time, I have incorporated the answer from YawarRaza7349.
Now, my code looks like this:
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IndexTupleIterator.java: an iterator that generates index tuples in lexicographic order, Take III
(See the next iteration here.)
(See the previous iteration here.)
This time, I have incorporated a nice answer from Simon Forsberg.
Now, my code looks like this:
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IndexTupleIterator.java: an iterator that generates index tuples in lexicographic order, Take II
(See the previous iteration here.)
(See the next iteration here.)
This time, I improved the iterator such that there is no chance of numeric overflow when computing the total number of iterations. To ...
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IndexTupleIterator.java: an iterator that generates index tuples in lexicographic order
(See the next iteration here.)
Intro
This time, I have an Iterator<List<Integer>> implementation that generates list index tuples in lexicographic order....
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STL style iterator template for arbitrary trees in C++20
In different code bases I regularly encounter tree data structures of different design and usually need to traverse it at some point. I finally got tired of writing yet another iterative traversal by ...
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Recursively iterate over every object in an object graph looking for specific types
I have an object graph which contains two types of objects that I care about:
Link objects that contain an ID and a reference to the object with that ID.
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Odometer in Rust
I am trying to implement an odometer in Rust. This should a be an iterator that yields items of type [u16; N] and it should be generic over const ...
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A dynamic array with an iterator compatible with std::sort
I wrote a Vector (dynamic array) class with an iterator usable with std::sort() . It seems to pass my tests.
I wondering about the issues one can spot on this ...
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Iterate internal array for a VBA class
After spending a considerable amount of time poking at the internals of the Collection class, I have discovered 2 methods to iterate a private internal array within ...
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Finding highly correlated variables in a dataframe by evaluating its correlation matrix's values
I read data from Excel into a Pandas DataFrame, so that every column represents a different variable, and every row represents a different sample. I made the function below to identify potential ...
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Improving efficiency of Rust algorithm ported from Python generator
I'm learning Rust by solving ProjectEuler problems.
To this end, I am trying to port a solution to problem 88 (link) in Python that heavily relies on generators to Rust (which doesn't have generators)....
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Extend iterators with until() function
I want to extend generic iterators with a convenience function until() that works like an inversion of take_while().
Here is the ...
user51621
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Max Stack implementation in C++ involving iterators
The tricky thing was keeping copies of list iterators in a tree map and managing both together. I'm not handling invalid input cases (like popping an empty stack) in this code. I am following Google C+...
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Convert Rankine temperatures to Celsius
I have this Python Package called ToTemp under development for precise Temperature Conversions and currently thinking in changing the method's implementation to be ...
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2D Matrix in C++
I wanted to play with a two-dimensional generic data container in C++ and explore different methods of traversals: using closures and iterators. I'd like a review of it.
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Middle of the Linked List in Rust
Yesterday, inspired by some great questions here, I decided to give myself some practice with Rust, by solving all the introductory questions over on LeetCode. It was a great learning exercise, and ...
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2021 Day 1 Advent of Code in Rust
I'm preparing for the Advent of Code 2022, and in order to shake off the cobwebs, I'm attempting some problems from the previous year in rust. Starting at Day 1, I've been trying to get comfortable ...
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Finding the number of possible paths in a cave system (Python)
I've finally come up with working solution for day 12 of AdventOfCode, where you have to find the number of possible paths in a cave system following a given set of rules (described below). My ...
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Dont let duplicated values in Iterator return of a function
I'm trying to build a function to return an Iterator with no duplicated float values, its working, but there is a better way of handling this duplicated values?
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Merge two strictly increasing sequences, without duplicates
This work is motivated by Sum of natural numbers below threshold, where several Swift solutions to Project Euler #1 (with arbitrary upper bound) are provided.
One way to think of it is to
start with ...
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Iterating over all simple unique cycles in an undirected graph in Java - brute-force approach
This post is about an Iterator iterating over simple loops of an undirected graph.
In the above graph, the cycle \$\langle 1, 2, 3, 4, 5, 3, 1 \rangle\$ is not ...
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Implementing Ord trait for an Iterator Wrapper
Recently, I needed to sort iterators by their first value and/or use them in BinaryHeap. There are things I don't like about this implementation:
Using RefCell.
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Matrix implementation
I am trying to implement an optimal and fast running matrix in C++. I need some review of the code and ideas on how to improve the code quality if it shall be.
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A prime iterator in JavaScript
This is an implementation of a Sieve of Eratosthenes as [Symbol.iterator] in JavaScript.
Comments welcome, my JS is a bit rusty. Making a class of this is mainly the reason to have fun with the ...
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Find longest palindrome in a string (LeetCode problem 5)
The code below is my solution to the following problem (problem #5 on LeetCode):
Given a string s, return the longest palindromic substring in s.
I wonder whether my use of iterators is an overkill. ...
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Zipping two lists with an offset in Python
Walking my first steps in Python from C, I find myself missing pointers from time to time.
In this case I want to go through a list processing two element at a time, where those elements are step ...
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Action on each element of an inline list
I'm trying to learn the "functional" part of C#/.Net for work, and I'm not sure if this is a good way to write this statement.
I was also trying to reduce duplicated code while not ...
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2d Grid - Iterating by Rows / Cells - Take #3
Edited with a bit more unit tests.
Preface
Following my second version:
2d Grid - Iterating by Rows / Cells - Take #2
I believe that I am now satisfied with this new version below.
There is still one ...
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Prime numbers iterator
I am not familiar with iterators. I am confused with the traits approach and the traditional one. I don't know which one I should use in 2021.
I wrote a minimal ...
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2d Grid - Iterating by Rows / Cells - Take #2
Preface
Following my first POC version:
2d Grid - Iterating by Rows / Cells
I have gained much more understanding, and present
A new version
A new version is ready, with templates and an attempt at ...
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Custom implementation to provide an immutable range of a container without copying it
I needed to pass a const reference to part of a std::vector without copy. I posted the previous version in my earlier question, thank you for the great support! As ...
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2d Grid - Iterating by Rows / Cells
The feature
Here is a Grid class representing a 2d grid.
The class will get templated once it reach a satisfactory state.
At this time the cells are int values.
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Custom implementation to provide an immutable range of a vector without copying it
Edit: A new and improved version can be found in this question, based on the feedback!
I needed to pass a const reference to part of a std::vector without copy.
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A counting loop class v2
Rewrite of A simple counting loop class based on feedback:
This version adds a step parameter and better iterator concept support.
Counting is always done in a signed integral, and only integers and ...
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A simple counting loop class
EDIT: Updated version available here: A counting loop class v2
Ranges (C++20) aren't quite ready, so until then, I needed a reliable counting loop class that works fairly well to replace the old-...
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Single-linked-list in C++ with iterators
I'm implementing a single linked list as close as it could be to std::forward_list. I would welcome a review and also more suggestions on what to test additionally.
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Left Shift/ Right Shift an array in C
I am trying to implement a Left shift/ Right Shift on arrays.
I was able to accomplish this using double loops.
Can the efficiency be improved?
This is the working code for LeftShift/RightShift which ...
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Radio with channels
Realize the Radio and Channel classes that represent radio and a radio station. The radio class offers an argumentless constructor and the following methods:
addChannel: stores and returns a new ...
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Using the Decoder class in a streaming context
Am experimenting with the IAsyncEnumerable interface and PipeReader class. Have come up with the following to decode a stream of bytes into chunks of characters and am able to decode all of my test ...
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Python's enumerate for C++
I implemented an enumerate() method for C++ containers similar to Python's enumerate to iterate through a range with an index and the actual value.
I have the following questions:
Does the usage of ...
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Iterate through non-empty words from text files
Given a file or directory, create an iterator that returns the non-empty words from the file or from all files recursively in the directory. Only process ".txt" files. Words are sequence of ...
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Bidirectional iterate over list in Python
I wrote a short function to iterate over a list starting at a given index, then flipping back and forth between left and right values.
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Iterating 2d array
I have implemented a MatrixIt class to traverse a 2D array. Is it possible to make the code clearer and shorter?
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Scraping odds portal with beautiful soup
This code scrapes www.oddsportal.com for all the URLs provided in the code and appends it to a dataframe.
I am not very well versed with iterative logic hence I am finding it difficult to improvise on ...
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Adding iterators to C++ sqlite wrapper class
I recently put up my C++ class to wrap the sqlite3 c library here:
Thin C++ wrapper for sqlite3 C library
One of the suggestions was rather than to specify a vector for arguments to functions instead ...
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Image (Const) Iterator using C++17
I am trying to learn how to correctly implement an iterator (and its corresponding const variant) using a single template, so I would appreciate any criticism to the following code. It's an forward ...
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Implement a range behaviour in Python using iterators
I've been assigned the following Python homework:
Implement myrange that acts like range using iterators. Define a function ...
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Rcpp sparse CSC matrix class
This is a sparse matrix (dgCMatrix) class that extends Rcpp.
WHAT: This class includes Rcpp::NumericVector and ...
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Racing promises and consuming them in the order of their resolution time
The ideas are
When multiple async calls are made, to be able to start consuming from the first resolving one regardless in what order the promises are fired.
To construct a modern emitter of async ...
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