I'm streaming a very large collection through a script and am currently using ifilter in a simple call to reject certain values, i.e.: ifilter(lambda x: x in accept_list, read_records(filename)) That's one predicate, but now it's occurred to me I should add another, and I might want to add others in the future. The straightforward way...
Current version: def chop(ar,size): p=len(ar)/size for i in xrange(p): yield ar[(i*size):((i+1)*size)] ar is type of list(). What i want is that chop() takes iterator and return iterator. for i in chop(xrange(9),3): for j in i: print j, print prints 0 1 2 3 4 5 6 7 8 ...
Basically, i have a series of steps that are processed using the pipes-filter pattern using the typical form: public interface IOperation<IN, OUT> { Iterator<OUT> execute(Iterator<IN> input); } So if i have a pipeline with steps X->Y->Z. I want to be able to batch the outputs of filter X and execute all subsequent steps Y and Z (...
I have an array of Elements, and each element has a property :image. I would like an array of :images, so whats the quickest and least expensive way to achieve this. Is it just iteration over the array and push each element into a new array, something like this: images = [] elements.each {|element| images << element.image} ...
To loop over elements of a container, I would typically use an iterator, like so: container<type> myContainer; // fill up the container container<type>::iterator it; for(it=myContainer.begin(); it!=myContainer.end(); ++it) { //do stuff to the elements of the container } Now, if I want to parallelize the loop using OpenMP, I might t...
For a personal project I have been implementing my own libstdc++. Bit by bit, I've been making some nice progress. Usually, I will use examples from http://www.cplusplus.com/reference/ for some basic test cases to make sure that I have the obvious functionality working as expected. Today I ran into an issue with std::basic_string::repla...
Is it possible to iterate through a LL in Java using a ListIterator, add objects periodically to the list, and process these items in the list in the order they were added? Let's say I start with a LL with a single object in it. I process this object, and decide I want to add two additional objects, which I want to further process (lik...
I want to convert generator or iterator to list recursively. I wrote a code in below, but it looks naive and ugly, and may be dropped case in doctest. Q1. Help me good version. Q2. How to specify object is immutable or not? import itertools def isiterable(datum): return hasattr(datum, '__iter__') def issubscriptable(datum): ...
I'm trying to convert an iterator class I have to be stl compatible so that it can be used with the stl algorithms. In the following simple (and frankly useless) example, which should print the values 0 to 5 inclusive, I am getting the following errors, ISO C++ forbids incrementing a pointer of type ‘Iterator (*)()‘ and, invalid conve...
I have the following code. template<class key,class val> bool has_key(key chkey,std::map<key,val> map){ for (std::map<key,val>::iterator it = map.begin(); #line 13 referenced by gcc it!=map.end(); ++it){ if(chkey == it->first) return true; } return false; } GCC is giving me the following error. objects.hpp: In functio...
The documentation for boost's specialized iterator adaptors states that boost::reverse_iterator "Corrects many of the shortcomings of C++98's std::reverse_iterator." What are these shortcomings? I can't seem to find a description of these shortcomings. FOLLOW-UP QUESTION: How does boost::reverse_iterator correct these shortcomings? ...
Hi All, I have below snippet which use the generator to give the new ID ... def __init__(self, id_generator = None): if id_generator is None: id_generator = 0 if isinstance(id_generator, int): import itertools self._generator = itertools.count(id_generator) else: self....
Hi, I'm parsing this JSON string with the libs in org.json and I can't understand why I get the output below into the log. ArrayList<String> al = new ArrayList<String>(); JSONObject demo = new JSONObject("{\"00408C88A2E6\":{\"id\":\"00408C88A2E6\",\"name\":\"Lab\"},\"00408C91188B\":{\"id\":\"00408C91188B\",\"name\":\"Lab1\"},\"00408C944...
In the code below, I tried iterating over the JSON object string. However, I do not get the desired output. My output on the webpage looks something like:- +item.temperature++item.temperature++item.temperature++item.temperature+ The alert that outputs the temperature works well. The part where I try accessing the value by iterating thr...
I have an iterator of lines from a very large file that need to be put in groups as I move along. I know where each group ends because there is a sentinel value on the last line of each group. So basically I want to write a function that takes an iterator and a sentinel value, and returns an iterator of groups each terminated by the sent...
Note that the order can go either way (erase first then push back, just that this way doesn't require creating a local reference to the object). for ( GameObjItr gameObj = m_gameObjects.begin(); gameObj != m_gameObjects.end(); gameObj++ ) { if ( *gameObj && *gameObj != gameObject ) { const sf::FloatRect &otherObj = (...
Hi, Im trying to make dynamic column list that will be 4 columns total (PHP). Im echoing an array and after every time 4 array items are echod, I would like to wrap those 4 array items in a div called "column". So basically, I thought I could do this with a self counting $i++ statement, but first off I'm having trouble starting the cou...
Hey everyone, So I've done some looking online and throught the documentation, but I'm having troubling finding out how to do this. I am working on creating an adventure game. I have a level class (which contains a bunch of rooms) and a Room class. I would like to be able to do something like the following. l = Level() for room in l: ...
I have a underlying API that passes a const char* and a length: foo(const char* data, const uint32_t len); I'd like to wrap this data/length in a light weight container that can be iterated and has the ability to be randomly accessed but not make a copy (e.g. like a vector). What is the best way to achieve this? The const char* data i...
I used iterator in my strut application like s:iterator value="resultList" id="resultData" status="stat" > s:hidden name="orderItemsList[%{index}].totalCostPrice" id="%{#costPriceId}" value="%{#resultData.totalCostPrice}"/> /s:iterator> here,I got an error when its found totalCostPrice value 0(Zero). ...