This is a great question. I’ll try to show you how we can use Python’s introspective abilities and open source to get an answer. We can use the dis module to peek behind the curtain and see how the CPython interpreter implements a for loop over an iterator. >>> def for_loop(iterable): … for item in … Read more
Here are some articles you might find of interest Giving STL Iterators a Base Class Type Erasure for C++ Iterators any_iterator Class Reference
I think the reason is simple. lists are ordered, dicts (prior to Python 3.6/3.7) and sets are not. So modifying a lists as you iterate may be not advised as best practise, but it leads to consistent, reproducible, and guaranteed behaviour. You could use this, for example let’s say you wanted to split a list … Read more
I would use a Map myself. But taking you at your word that a pair of arrays makes sense in your case, how about a utility method that takes your two arrays and returns an Iterable wrapper? Conceptually: for (Pair<K,V> p : wrap(list1, list2)) { doStuff(p.getKey()); doStuff(p.getValue()); } The Iterable<Pair<K,V>> wrapper would hide the bounds … Read more
From Apples’ Objective-C documentation on fast enumeration: For collections or enumerators that have a well-defined order—such as NSArray or NSEnumerator instance derived from an array—the enumeration proceeds in that order, so simply counting iterations will give you the proper index into the collection if you need it.
This article (#3) ran some performance tests and found that the jQuery .each function was about 10x as slow as the native javascript for loop. From 10 Ways to Instantly Increase Your jQuery Performance – 3. Use For Instead of Each Using Firebug, it’s possible to measure the time each of the two functions takes … Read more
Perhaps a bit more theoretical. Mathematically, collections in C++ can be described as a half-open interval of iterators, namely one iterator pointing to the start of the collection and one iterator pointing just behind the last element. This convention opens up a host of possibilities. The way algorithms work in C++, they can all be … Read more
There’s nothing wrong with direct, “ad-hoc” solution. It can be clean enough too. Just notice that spiral is built from segments. And you can get next segment from current one rotating it by 90 degrees. And each two rotations, length of segment grows by 1. edit Illustration, those segments numbered … 11 10 7 7 … Read more