I'm writing some Rails code for a partial view, and I want it to only show a comment field if somebody is already logged onto a site here. If the page is viewed by someone who isn't a member of the site yet, the shared/comment_not_logged_in fragment should be passed in. However, I'm totally stumped as to why I can't run the same check ...
In my quest to transition from a decade of C++ to Ruby, I find myself second guessing how to accomplish the simplest things. Given the classic shape derivation example below, I'm wondering if this is "The Ruby Way". While I believe there's nothing inherently wrong with the code below, I'm left feeling that I'm not harnessing the full p...
I have: var keys = [ "height", "width" ]; var values = [ "12px", "24px" ]; And I'd like to convert it into this object: { height: "12px", width: "24px" } In Python, there's the simple idiom dict(zip(keys,values)). Is there something similar in jQuery or plain Javascript, or do I have to do this the long way? ...
I need to derive an important value given 7 potential inputs. Uncle Bob urges me to avoid functions with that many parameters, so I've extracted the class. All parameters now being properties, I'm left with a calculation method with no arguments. “That”, I think, “could be a property, but I'm not sure if that's idiomatic C#.” Should I...
I believe you must be familiar with this idiom, which is sort of java's excuse for closures //In the "Resource Manager" class public void process(Command cmd){ //Initialize ExpensiveResource resource = new ExpensiveResource(); //Use cmd.execute(resource); //Release / Close resource.close(); } //In the Client class... manage...
If you want to check if something matches a regex, if so, print the first group, you do.. import re match = re.match("(\d+)g", "123g") if match is not None: print match.group(1) This is completely pedantic, but the intermediate match variable is a bit annoying.. Languages like Perl do this by creating new $1..$9 variables for mat...
I'm finding myself typing the following a lot (developing for Django, if that's relevant): if testVariable then: myVariable = testVariable else: # something else Alternatively, and more commonly (i.e. building up a parameters list) if 'query' in request.POST.keys() then: myVariable = request.POST['query'] else: # somethin...
Consider the following contrived example: void HandleThat() { ... } void HandleThis() { if (That) return HandleThat(); ... } This code works just fine, and I'm fairly sure it's spec-valid, but I (perhaps on my own) consider this unusual style, since the call appears to return the result of the function, despite the fact that ...
I have a standard many-to-many relationship between users and roles in my Rails app: class User < ActiveRecord::Base has_many :user_roles has_many :roles, :through => :user_roles end I want to make sure that a user can only be assigned any role once. Any attempt to insert a duplicate should ignore the request, not throw an error ...
Let's say there is a function like void SendToTheWorld(const Foo& f); and I need to preprocess Foo object before sending X PreprocessFoo(const Foo& f) { if (something) { // create new object (very expensive). return Foo(); } // return original object (cannot be copied) return f; } Usage Foo foo; SendToT...
if params[:parent_type] == "Order" parent_id = nil else parent_id = params[:parent_id] end Would a Ruby person laugh at me for writing it this way? It doesn't seem particularly concise like some Ruby code I've seen. ...
I'm a Mac user, so I know that for Mac OS X, I'd like my games packaged up in a nice .app bundle (like Aquaria did, for example). But what is the standard on Windows? And what is the standard on Linux? I'm relatively unfamiliar with both, but from what I understand, there's no equivalent of a Mac application bundle on either. Do users t...
I have a model that needs to have a field named complex and another one named type. Those are both python reserved names. According to PEP 8, I should name them complex_ and type_ respectively, but django won't allow me to have fields named with a trailing underscore. Whats the proper way to handle this? ...
I'm putting together some brief pages on programming and programming languages for a corporate wiki. We are not a software or IT company, but we have many technical employees (engineers, geoscientists...). I'd like to implement a brief example program (think no more than 5x the complexity of "Hello World", if that's a measurable metri...
Ok, consider this common idiom that most of us have used many times (I assume): class FooBarDictionary { private Dictionary<String, FooBar> fooBars; ... FooBar GetOrCreate(String key) { FooBar fooBar; if (!fooBars.TryGetValue(key, out fooBar)) { fooBar = new FooBar(); fo...
I just invented a stupid little helper function: def has_one(seq, predicate=bool): """Return whether there is exactly one item in `seq` that matches `predicate`, with a minimum of evaluation (short-circuit). """ iterator = (item for item in seq if predicate(item)) try: iterator.next() except StopIteration...
I could do this easily in C++ (note: I didn't test this for correctness--it's only to illustrate what I'm trying to do): const int BadParam = -1; const int Success = 0; int MyFunc(int param) { if(param < 0) { return BadParam; } //normal processing return Success; } But I cannot ...
I'd like to know the best way (more compact and "pythonic" way) to do a special treatment for the last element in a for loop. There is a piece of code that should be called only between elements, being suppressed in the last one. Here is how I currently do it: for i, data in enumerate(data_list): code_that_is_done_for_every_element ...
How can you keep track of time in a simple embedded system, given that you need a fixed-point representation of the time in seconds, and that your time between ticks is not precisely expressable in that fixed-point format? How do you avoid cumulative errors in those circumstances. This question is a reaction to this article on slashdot....
For instance, in Python, I can create a class like this: class foo(object): bar = 'x' def __init__(self, some_value): self.some_attr = some_value ...where bar is a class attribute and some_attr is an instance attribute. What is the idiomatic way to do things like this in Ruby? ...