>>> a=range(5) >>> [a[i] for i in range(0,len(a),2)] ## list comprehension for side effects [0, 2, 4] >>> a [0, 1, 2, 3, 4] >>> [a[i]=3 for i in range(0,len(a),2)] ## try to do assignment SyntaxError: invalid syntax >>> def setitem(listtochange,n,value): ## function to overcome limitation listtochange[n]=value return value >>> ...
Any code can provide side effects. Most of the time, side effects can be a sign of bad design and/or need of refactorisation, but when unit testing I find it hard to test against. Consider the following example: [Test] public void TrimAll_Removes_All_Spaces() { // Arrange var testSubject = "A string with lots of sp...
For context: this is an HTML app, with little or no browser side JavaScript. I can't easily change that so need to do this on the server. CouchDB is built to not have side effects. This is fair enough. But there seems to be no method that i can conceive of with shows, views, lists to change what is shown to a user with subsequent req...
Let's say you're writing a function to check if a page was reached by the appropriate URL. The page has a "canonical" stub - for example, while a page could be reached at stackoverflow.com/questions/123, we would prefer (for SEO reasons) to redirect it to stackoverflow.com/questions/123/how-do-i-move-the-turtle-in-logo - and the actual r...
Yesterday I watched the screencast Writing your first Rx Application (on Channel 9) where Wes Dyer shows how to implement Drag 'n' Drop using Reactive Extensions (Rx). Something that I still don't understand: Towards the end of the screencast, Wes Dyer types in the following: var q = from start in mouseDown from delta in mouseM...
Look at this code: #include <framework_i_hate.h> int main() { XFile file("./my_file.xxxx", "create"); XObject object("my_object"); // modify the object object.Write(); } Try to guess where object will be saved... yes, you guessed it. I think this is too magic, I'd like to write something like object.Save(file), but it's not n...
I just got my copy of Expert F# 2.0 and came across this statement, which somewhat surprised me: For example, when necessary, you can use side effects on private data structures allocated at the start of an algorithm and then discard these data structures before returning a result; the overall result is then effectively a...