scope

问题 MetaSearch's handy functions such as .not_in worked in Rails 3.0 & 3.1 inside of scope calls. I had to rewrite some scopes to be "plain Rails 3.2" without MetaSearch convenience even though MetaSearch works outside of scope. And it broke several of my apps & tools when I upgraded. Ideas? I am using MetaSearch everywhere. Even wrote a custom predicate. Still could be missing something obvious I hope. On Rails 3.2, working inside an engine for code separation. Didn't seem to matter when I tried

问题 I've a crazy problem. I'm instantiating an object from a class. Then I want to pass a function from this object to the setInterval function. The whole code block is executed with a keyDown event. Here's the code: function doKeyDown(e){ var instance = new Class(e.keyCode); setInterval(instance.functionToBeExecuded(), 200); } The strange thing is that it's getting executed once and then starts to loop an error which states (firebug): 27 SyntaxError: missing ] after element list [object

问题 Using Scala 2.10, the following compiles without an error. val test = 1 try { val test = 2 } Looking at the byte code generated, I see this: int test = 1; int test = 2; Isn't this strange? Or am I missing something obvious? 回答1: This has nothing to do with try . Variables can shadow each other in any block, and you can put blocks basically anywhere: val x = 0 if ({val x = 1; x*3}==0) { val x = 2; x + x + x } else x This makes code more portable: you can freely move blocks around without

问题 I want to iterate over all instances of defined types (ex. Apache::Vhost). However this loop only list my resources under the scope. <% scope.catalog.vertices.each do |resource| -%> <%# if resource.type == "Apache::Vhost" -%> #Include <%= resource.title %> <% end -%> 回答1: Walking the catalog durig at compile time ("catalog building") is a Bad Idea. If you really want this functionality, think about moving the iteration code to a custom provider that will generate the file content akin to what

问题 I am writing a procedure in scheme and I am trying to manipulate the values of variables. I use the define function to give a value to a variable but I can't change the value. I would have used the let function but the variable change is only effective in the body of the let function. Are there other ways to manipulate variabes and be able to view the changes from anywhere in the procedure? Thanks 回答1: you can use set! set-car! set-cdr! after the variable has been defined 来源： https:/

问题 This question already has answers here : Surprised that global variable has undefined value in JavaScript (6 answers) Closed 5 years ago . I m a newbie to javascript. I usually program in Java. I am confused by this following code snippet. <script> x = "foo"; function bar(p){ if (p){ document.writeln("x = " + x); } else { var x = "baz"; } } bar("baz"); </script> When I run the above code snipped its printing x = undefined Why does it print undefined, since x is a global variable it should

问题 When passing a method pointer to google.maps.event.addListener , google maps seems to overwrite it's this reference with an instance of google.maps.Map , therefore it renders it useless if the methods references any of its prototype memebers internally. The long story short, if I pass myObj.MyMethod as an event callback, at the time of its execution MyMethod.this reference will be an instance of google.maps.Map rather then myObj . Is there any way to safely pass a method pointer to

问题 I'm having a problem ordering an array that I've successfully paginated with Kaminari. In my controller I have: @things = @friend_things + @user_things @results = Kaminari.paginate_array(@things).page(params[:page]).per(20) I want to have the final @results array ordered by :created_at , but have had no luck getting ordering to work with the generic array wrapper that Kaminari provides. Is there a way to set the order in the Kaminari wrapper? Otherwise what would be the best way? Thanks. 回答1:

问题 SOLVED - This example code worked, so I compared it to the non-working I had and found a discrepancy. In my code, the one that did not work, when declaring the color array I forgot to add a "var" before it. m_color = []; m_color[0] = 255; m_color[1] = 255; m_color[2] = 255; m_color[3] = 255; instead of: var m_color = []; m_color[0] = 255; m_color[1] = 255; m_color[2] = 255; m_color[3] = 255; That's it. No error was generated and I guess it created it as a global array shared by all the

问题 I'm working on this problem and I got the answers : Statically: 20, 16 Dynamically: 20, 100 is that correct? Consider the program below (in a Pascal like language). What is the output of the language is statically scoped? What is the output if the language is dynamically scoped? Program main; x: integer; procedure f1(z: integer) begin return z * x; end procedure f2(z: integer) int x; begin x = 2; return f1(z) * x; end begin /* main program */ x = 5; print f1(4); print f2(4); end 回答1: Why not