I just saw this nice copy-on-write pointer implementation. It looks pretty generic and useful, so my question is: Is such a class contained in any of the C++ toolkits (boost, loki, etc.)? If not, I'd really like to know why because it is a really useful idiom and apparently a generic implementation seems doable (like the one I linked to)...
In some sports certain techniques or elements are named after the athlete who invented or first performed themfor example, Biellmann spin. Is their widespread use of such names for programming techniques and idioms? What are they? To be clear, I am explicitly not asking about algorithms, which are quite often named after their creator...
For instance, say I wanted a function to escape a string for use in HTML (as in Django's escape filter): def escape(string): """ Returns the given string with ampersands, quotes and angle brackets encoded. """ return string.replace('&', '&').replace('<', '<').replace('>', '>').repla...
Are there any idioms for returning multiple values from a bash function within a script? http://tldp.org/LDP/abs/html/assortedtips.html describes how to echo multiple values and process the results (e.g., example 35-17), but that gets tricky if some of the returned values are strings with spaces in. A more structured way to return woul...
Hi is there a standard place for accessing empty array constants in the JDK > 1.5. When I want to do a conversion from a String Collection (e.g. ArrayList)to a String Array I find myself using my own which is defined in my own Constants class: public static final String[] EMPTY_STRING_ARRAY = new String[0]; And then in my client cod...
Hello! How to write the exprission shorter: return '%.0f' % float_var if float_var else float_var or if float_var: return formatted_string else: return None Thanks! ...
Hey, I have recently started a project in Ruby on Rails. I used to do all my projects before in Python but decided to give Ruby a shot. In the projects I wrote in Python I used a nice little technique explained by the correct answer in this post: http://stackoverflow.com/questions/277965/dictionary-or-if-statements-jython I use this...
Hello SO. I'm trying to make an API for my rails application using JSON responses to RESTful resource controllers. This is a new experience for me, so I'm looking for some guidance and pointers. To start things off: In a rails application, what is the "proper" way to respond with JSON to REST-ful controller methods? (create, update, d...
Hey guys, I feel like I spend a lot of time writing code in Python, but not enough time creating Pythonic code. Recently I ran into a funny little problem that I thought might have an easy, idiomatic solution. Paraphrasing the original, I needed to collect every sequential pair in a list. For example, given the list [1,2,3,4,5,6], I ...
I've been trying to get a good hold on the x86 assembly language, and was wondering if there was a quick-and-short equivalent of movl $1, %eax. That's when I thought that a list of idioms used frequently in the language would perhaps be a good idea. This could include the preferred use of xorl %eax, %eax as opposed to movl $0, %eax, or ...
My PHP experience is rather limited. I've just inherited some stuff that looks odd to me, and I'd like to know if this is a standard way to do things. The page which shows up in the browser location (e.g. www.example.com/example_page) has something like: <? $title = "Page Title"; $meta = "Some metadata"; require("pageheader.inc"); ?> ...
Say I have a function foo that I want to call n times. In Ruby, I would write: n.times { foo } In Python, I could write: for _ in xrange(n): foo() But that seems like a hacky way of doing things. My question: Is there an idiomatic way of doing this in Python? ...
I find myself using hash arguments to constructors quite a bit, especially when writing DSLs for configuration or other bits of API that the end user will be exposed to. What I end up doing is something like the following: class Example PROPERTIES = [:name, :age] PROPERTIES.each { |p| attr_reader p } def initialize(args) ...
I answered this question, and Potatoswatter answered too as The modern C++ equivalent would be a sentry object: construct it at the beginning of a function, with its constructor implementing call(), and upon return (or abnormal exit), its destructor implements I am not familiar with using sentry objects in C++. I thought...
I am processing a XML document and iterating through nodes. I want to iterate through the nodes and build a new List of some type. How would I do this with Scala: Here is my XML traverse code: def findClassRef(xmlNode: Elem) = { xmlNode\"classDef" foreach { (entry) => val name = entry \ "@name" val classid =...
If I have a constructor with say 2 required parameters and 4 optional parameters, how can I avoid writing 16 constructors or even the 10 or so constructors I'd have to write if I used default parameters (which I don't like because it's poor self-documentation)? Are there any idioms or methods using templates I can use to make it less te...
I'm familiar with printing time difference in milliseconds: long time = System.currentTimeMillis(); //do something that takes some time... long completedIn = System.currentTimeMillis() - time; But, is there a nice way print a complete time in a specified format (eg: HH:MM:SS) either using Apache Commons or even the dreaded platform...
I would like to calculate the difference in weeks between two dates, where two dates are considered part of the same week if their preceding Sunday is the same. Ideally, I'd like to do this using DATEDIFF, instead of learning an elaborate idiom to calculate the value. But I can't tell how it works when weeks are involved. The following ...
Which is preferred ("." indicating whitespace)? A) def foo(): x = 1 y = 2 .... if True: bar() B) def foo(): x = 1 y = 2 if True: bar() My intuition would be B (that's also what vim does for me), but I see people using A) all the time. Is it just because most of the editors out there are bro...
Hi all, In C++ an interface can be implemented by a class with all its methods pure virtual. Such a class could be part of a library to describe what methods an object should implement to be able to work with other classes in the library: class Lib::IFoo { public: virtual void method() = 0; }; : class Lib::Bar { p...