I'm currently using POI to attempt to extract text out of a batch of Word documents and I need to be able to determine what entries a document contains. I've been able to get as far as pulling the document root and pulling the first entry but I want to be able to view all entries. the getEntries() method seems to provide this functiona...
I see a lot of c++ code that looks like this: for( const_iterator it = list.begin(), const_iterator ite = list.end(); it != ite; ++it) As opposed to the more concise version: for( const_iterator it = list.begin(); it != list.end(); ++it) Will there be any difference in speed between these two conventions? Naively the...
I am sure it's an obvious error with my logic, but I can't seem to work out what I am doing wrong. Quite simply I have an array list of security codes, I want to compute the correlation between each combination of security codes. My code is as follows: private void crossCorr(ArrayList<String> codes, HashMap<String, Stock> stockMap){ /...
In Java, I need to return an Iterator from my method. My data comes from another object which usually can give me an iterator so I can just return that, but in some circumstances the underlying data is null. For consistency, I want to return an "empty" iterator in that case so my callers don't have to test for null. I wanted to write ...
I want to do something like this: std::vector<int>::iterator it; // /cut/ search for something in vector and point iterator at it. if(!it) //check whether found do_something(); But there is no operator! for iterators. How can I check whether iterator points at anything? ...
I have barely squeaked by my last cs class and now I am in data structures. I am building a binary tree structure from scratch and I am a little confused on how the iterator will work. I understand how they work in double linked lists, but am not sure how this one will work................ thanks. ...
I have this script- import lxml from lxml.cssselect import CSSSelector from lxml.etree import fromstring from lxml.html import parse website = parse('http://xxx.com').getroot() selector = website.cssselect('.name') for i in range(0,18): print selector[i].text_content() As you can see the for loop stops after a number of ti...
The "yield" statement in python allows simple iteration from a procedure, and it also means that sequences don't need to be pre-calculated AND stored in a array of "arbitrary" size. Is there a there a similar way of iterating (with yield) from a C procedure? ...
Suppose I have a list, in which no new nodes are added or deleted. However, the nodes may be shuffled around. Is it safe to save an iterator, pointing to a node in the list, and access it at some arbitrarily later time? Edit (followup question): The documentation for list::splice() says that it removes elements from the argument list....
At the Boost library conference today, Andrei Alexandrescu author of the book Modern C++ Design and the Loki C++ library, spoke about why iterators are bad, and he had a better solution. I tried to read the presentation slides, but could not get much out of them. I have these questions for the StackOverflow community: Are iterators ba...
I have a class TContainer that is an aggregate of several stl collections pointers to TItems class. I need to create an Iterator to traverse the elements in all the collections in my TContainer class abstracting the client of the inner workings. What would be a good way to do this?. Should I crate a class that extends an iterator (if ...
I've written a few functions with a prototype like this: template <typename input_iterator> int parse_integer(input_iterator &begin, input_iterator end); The idea is that the caller would provide a range of characters, and the function would interpret the characters as an integer value and return it, leaving begin at one past the last...
I am looking for a Java class where I can specify a set of date rules, such as "every 3rd sunday" and "the first occurrence of a monday every second month". I want to be able to get something like an infinite iterator out of it (.next() would return the next date matching the rules set). I think I'd be able to build it myself - but cale...
Hmmm... the Java Iterator<T> has a remove() method but not a replace(T replacement) method. Is there an efficient way to replace selected items in a List? I can use a for-loop to call get(i) and set(i) which is fine for ArrayList, but would suck for a linked list. ...
I have a class (foo) that contains a vector. If i try iterating over the elements in the vector like so: for(vector<random>::iterator it = foo.getVector().begin(); it != foo.getVector().end(); ++it) { cout << (*it) << endl; } The first element is always corrupted and returns garbage data. However, if do something like: ...
Let's say I have a sequential container, and a range (pair of iterators) within that container of elements that are currently 'active'. At some point, I calculate a new range of elements that should be active, which may overlap the previous range. I want to then iterate over the elements that were in the old active range but that are not...
How come that random deletion from a std::vector is faster than a std::list? What I'm doing to speed it up is swapping the random element with the last and then deleting the last. I would have thought that the list would be faster since random deletion is what it was built for. for(int i = 500; i < 600; i++){ swap(vector1[i], vector...
So for a type like: CoolCollection<T> you could have: foreach (T item in coolCollection) { ... } foreach (CoolNode node in coolCollection) { ... } If this isn't possible, maybe like foreach2, or some other way to iterate. Often times, I would really like more than 1 way of iterating on a type. EDIT: Sorry if it wasn't cle...
I created a program, and it uses the vector.h #include, and iterators, etc... But when I run the program, under certain circumstances (I'm still trying to figure out what those would be) I get an assertion error refering me to line 98 of vector.h. I went to line 98 of vector.h and got this: #if _HAS_ITERATOR_DEBUGGING if (this->_...
I've written a bit of code like the following to compare items with other items further on in a list. Is there a more elegant pattern for this sort of dual iteration? jump_item_iter = (j for j in items if some_cond) try: jump_item = jump_item_iter.next() except StopIteration: return for item in items: if jump_item is item: ...