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  • Generic foreach loop in C#.

    - by mcoolbeth
    The compiler, given the following code, tells me "Use of unassigned local variable 'x'." Any thoughts? public delegate Y Function<X,Y>(X x); public class Map<X,Y> { private Function<X,Y> F; public Map(Function f) { F = f; } public Collection<Y> Over(Collection<X> xs){ List<Y> ys = new List<Y>(); foreach (X x in xs) { X x2 = x;//ys.Add(F(x)); } return ys; } }

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  • C# 4.0 'dynamic' and foreach statement

    - by ControlFlow
    Not long time before I've discovered, that new dynamic keyword doesn't work well with the C#'s foreach statement: using System; sealed class Foo { public struct FooEnumerator { int value; public bool MoveNext() { return true; } public int Current { get { return value++; } } } public FooEnumerator GetEnumerator() { return new FooEnumerator(); } static void Main() { foreach (int x in new Foo()) { Console.WriteLine(x); if (x >= 100) break; } foreach (int x in (dynamic)new Foo()) { // :) Console.WriteLine(x); if (x >= 100) break; } } } I've expected that iterating over the dynamic variable should work completely as if the type of collection variable is known at compile time. I've discovered that the second loop actually is looked like this when is compiled: foreach (object x in (IEnumerable) /* dynamic cast */ (object) new Foo()) { ... } and every access to the x variable results with the dynamic lookup/cast so C# ignores that I've specify the correct x's type in the foreach statement - that was a bit surprising for me... And also, C# compiler completely ignores that collection from dynamically typed variable may implements IEnumerable<T> interface! The full foreach statement behavior is described in the C# 4.0 specification 8.8.4 The foreach statement article. But... It's perfectly possible to implement the same behavior at runtime! It's possible to add an extra CSharpBinderFlags.ForEachCast flag, correct the emmited code to looks like: foreach (int x in (IEnumerable<int>) /* dynamic cast with the CSharpBinderFlags.ForEachCast flag */ (object) new Foo()) { ... } And add some extra logic to CSharpConvertBinder: Wrap IEnumerable collections and IEnumerator's to IEnumerable<T>/IEnumerator<T>. Wrap collections doesn't implementing Ienumerable<T>/IEnumerator<T> to implement this interfaces. So today foreach statement iterates over dynamic completely different from iterating over statically known collection variable and completely ignores the type information, specified by user. All that results with the different iteration behavior (IEnumarble<T>-implementing collections is being iterated as only IEnumerable-implementing) and more than 150x slowdown when iterating over dynamic. Simple fix will results a much better performance: foreach (int x in (IEnumerable<int>) dynamicVariable) { But why I should write code like this? It's very nicely to see that sometimes C# 4.0 dynamic works completely the same if the type will be known at compile-time, but it's very sadly to see that dynamic works completely different where IT CAN works the same as statically typed code. So my question is: why foreach over dynamic works different from foreach over anything else?

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  • Dynamic Tree control in Flex 3

    - by nimmyliji
    I am looking for sample code to create a dynamic Tree control in Flex using a Collection of objects obtained from the backend(Perl cgi). So, initially the Tree will display the root nodes. Clicking root node, will invoke the data for populating the child nodes (basically adding child nodes on demand). Clicking child nodes will pull another collection add child nodes of child node. So, lets assume Initially the Tree will display - Root1 Root2 Root3 Clicking Root1 will display something like this - Root1 Child 1 Child 2 Root2 Root3 And Clicking Child1 will display - Root1 Child 1 Child1 of Child 1 Child2 of Child 1 Child 2 Root2 Root3 Is it possible? Thanks in advance...

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  • Beginner to RUBY - require_relative problem

    - by WANNABE
    Hi, I'm learning Ruby (using version 1.8.6) on Windows 7. When I try to run the stock_stats.rb program below, I get the following error: C:\Users\Will\Desktop\ruby>ruby stock_stats.rb stock_stats.rb:1: undefined method `require_relative' for main:Object (NoMethodE rror) I have three v.small code files: stock_stats.rb require_relative 'csv_reader' reader = CsvReader.new ARGV.each do |csv_file_name| STDERR.puts "Processing #{csv_file_name}" reader.read_in_csv_data(csv_file_name) end puts "Total value = #{reader.total_value_in_stock}" csv_reader.rb require 'csv' require_relative 'book_in_stock' class CsvReader def initialize @books_in_stock = [] end def read_in_csv_data(csv_file_name) CSV.foreach(csv_file_name, headers: true) do |row| @books_in_stock << BookInStock.new(row["ISBN"], row["Amount"]) end end # later we'll see how to use inject to sum a collection def total_value_in_stock sum = 0.0 @books_in_stock.each {|book| sum += book.price} sum end def number_of_each_isbn # ... end end book_in_stock.rb require 'csv' require_relative 'book_in_stock' class CsvReader def initialize @books_in_stock = [] end def read_in_csv_data(csv_file_name) CSV.foreach(csv_file_name, headers: true) do |row| @books_in_stock << BookInStock.new(row["ISBN"], row["Amount"]) end end # later we'll see how to use inject to sum a collection def total_value_in_stock sum = 0.0 @books_in_stock.each {|book| sum += book.price} sum end def number_of_each_isbn # ... end end Thanks in advance for any help.

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  • Error when compiling code with the Protege API

    - by Anto
    I am new to Protege API and I have just created on Eclipse a small application which uses an external OWL file. Also I did import all the necessary libraries. import java.util.Collection; import java.util.Iterator; import edu.stanford.smi.protege.exception.OntologyLoadException; import edu.stanford.smi.protegex.owl.ProtegeOWL; import edu.stanford.smi.protegex.owl.model.*; public class Trial { public static void main(String[] args) throws OntologyLoadException{ String uri = "C:/Documents and Settings/Anto/Desktop/travel.owl"; OWLModel owlModel = ProtegeOWL.createJenaOWLModelFromURI(uri); Collection classes = owlModel.getUserDefinedOWLNamedClasses(); for(Iterator it = classes.iterator(); it.hasNext();){ OWLNamedClass cls = (OWLNamedClass) it.next(); Collection instances = cls.getInstances(false); System.out.println("Class " + cls.getBrowserText()+ " (" + instances.size()+")"); for(Iterator jt = instances.iterator(); jt.hasNext();){ OWLIndividual individual = (OWLIndividual) jt.next(); System.out.println(" - "+ individual.getBrowserText()); } } } } When I do compile however I get the following errors: WARNING: [Local Folder Repository] The specified file must be a directory. (C:\Documents and Settings\Anto\My Documents\Eclipse Workspace\ProtegeTrial\plugins\edu.stanford.smi.protegex.owl) LocalFolderRepository.update() SEVERE: Exception caught -- java.net.URISyntaxException: Illegal character in path at index 12: C:/Documents and Settings/CiuffreA/Desktop/travel.owl at java.net.URI$Parser.fail(URI.java:2809) at java.net.URI$Parser.checkChars(URI.java:2982) at java.net.URI$Parser.parseHierarchical(URI.java:3066) at java.net.URI$Parser.parse(URI.java:3014) at java.net.URI.<init>(URI.java:578) at edu.stanford.smi.protegex.owl.jena.JenaKnowledgeBaseFactory.getFileURI(Unknown Source) at edu.stanford.smi.protegex.owl.jena.JenaKnowledgeBaseFactory.loadKnowledgeBase(Unknown Source) at edu.stanford.smi.protege.model.Project.loadDomainKB(Unknown Source) at edu.stanford.smi.protege.model.Project.createDomainKnowledgeBase(Unknown Source) at edu.stanford.smi.protegex.owl.jena.creator.OwlProjectFromUriCreator.create(Unknown Source) at edu.stanford.smi.protegex.owl.ProtegeOWL.createJenaOWLModelFromURI(Unknown Source) at Trial.main(Trial.java:14) Exception in thread "main" java.lang.NullPointerException at edu.stanford.smi.protegex.owl.jena.JenaKnowledgeBaseFactory.loadKnowledgeBase(Unknown Source) at edu.stanford.smi.protege.model.Project.loadDomainKB(Unknown Source) at edu.stanford.smi.protege.model.Project.createDomainKnowledgeBase(Unknown Source) at edu.stanford.smi.protegex.owl.jena.creator.OwlProjectFromUriCreator.create(Unknown Source) at edu.stanford.smi.protegex.owl.ProtegeOWL.createJenaOWLModelFromURI(Unknown Source) at Trial.main(Trial.java:14) Does anyone have an idea on where the problem should be?

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  • Add a link to a JQueryUI autocomplete item

    - by Tordek
    When a user starts typing on the searchbox, the suggestion page returns the latest item from all collections matching that nama, plus other data. I'd like to show that item (along its image), and a link to "see all items from this collection". I can do (most of) that with the following code: $('#search').autocomplete({ source: function (request, response) { $.ajax({ url: suggesturl, dataType: 'json', data: request, success: function (data) { response(data.map(function (value) { return { 'label': '<img src="' + value.thumbsmall + '" />' + value.name + '<a href="/">More items from this collection...</a>', 'value': value.fullname }; })); } }); }, minLength: 3 }) The problem is that, although the link appears in the box, when it's clicked it gets ignored, and the default select action is executed (the item's value is put into the textbox).

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  • POJO's versus Cursors in Android

    - by Kilnr
    I usually tend to define the model layer of my apps using POJO's, such as Article, Comment, etc. I was about to implement an AlphabetIndexer in the adapter of one of my ListViews. Right now this adapter accepts a Collection of Articles, which I normally get from my wrapper around an SQLiteDatabase. The signature of the AlphabetIndexer constructer is as follows: public AlphabetIndexer (Cursor cursor, int sortedColumnIndex, CharSequence alphabet) Since this doesn't accept a Collection or something similar, just a Cursor, it got me wondering: maybe I shouldn't be creating objects for my model, and just use the Cursors returned from the database? So the question is, I guess: what should I do, represent data with Collections of POJO's, or just work with Cursors throughout my app? Any input?

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  • WPF DataGridTextColumn Can't type point for float data

    - by Alvin
    I had a WPF DataGrid and use DataGridTextColumn Binding to a Collection. The items in Collection had some float property. When my program launched, I modify the value of float property in DataGrid, if I type a integer value, it works well. But if I type char . for a float value, char . can't be typed. I had to type all the numbers first, and then jump to the . position to type char . to finish my input. So how can I type . in my situation? Thanks.

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  • Entity Framework 4 relationship management in POCO Templates - More lazy than FixupCollection?

    - by Joe Wood
    I've been taking a look at EF4 POCO templates in beta 2. The FixupCollection looks fine for maintaining the model correctness after updating the relationship collection property (i.e. product.Orders it would set the order.Product reference ). But what about support for handling the scenario when some of those Order objects are removed from the context? The use-case of maintaining cascading deletes in the in-memory model. The old Typed DataSet model used to do this by performing the query through the container to derive the relationship results. Like the DataSet, this would require a reference to the ObjectContext inside the entity class so that it could query the top-level Order collection. Better support for Separation of Concerns in the ObjectContext would be required. It looks like EF is not suited to this use-case that DataSets did out of the box.... am I right?

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  • Diagramming in Silverlight MVVM- connecting shapes

    - by silverfighter
    Hi, have I have a quesition regarding MVVM pattern in the uses case of diagramming. What I have so far is a list of Items which are my Shapes. ObservableCollection<ItemsViewModels> Items; and a Collection of Connection of Items ObservableCollection<ConnectionViewModel> Each ItemViewModel has an ID and a ConnectionViewModel has two ID to connect the Items. My ItemsViewModel Collection is bound to a itemscontrol which is layout on a Canvas. With the ElementMouseDragBehavior I am able to drag my Items around. Now comes my big question =) How can I visualize my connections that I will be able to move the items around and the items stay connected with a line either straign or bezier. I don't know how to abstract that with the mvvm pattern. Thanks for any help...

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  • Serializing data using IEnumerable<T> with WebGet

    - by Jim
    possible duplicate: Cannot serialize parameter of type ‘System.Linq.Enumerable… ’ when using WCF, LINQ, JSON Hi, If my method signiature looks like this, it works fine. [WebGet] MyClass[] WebMethod() If the signiature looks like this [WebGet] IEnumerable<T> WebMethod() I get the following error: Cannot serialize parameter of type 'X.Y.Z.T+<WebMethod>d__2c' (for operation 'WebMethod', contract 'IService') because it is not the exact type 'System.Collections.Generic.IEnumerable`1[X.Y.Z.T]' in the method signature and is not in the known types collection. In order to serialize the parameter, add the type to the known types collection for the operation using ServiceKnownTypeAttribute. I have tried adding. ServiceKnownType(typeof(IEnumerable)) Same error. Is this a bug in 2010 beta 2, or is this likely to be correct going forward? Thanks

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  • Auto-scaffolding an "index" view in ASP.NET MVC

    - by DanM
    I'm trying to write an auto-scaffolder for Index views. I'd like to be able to pass in a collection of models or view-models (e.g., IQueryable<MyViewModel>) and get back an HTML table that uses the DisplayName attribute for the headings (th elements) and Html.Display(propertyName) for the cells (td elements). Each row should correspond to one item in the collection. Here's what I have so far: <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %> <% var items = (IQueryable<TestProj.ViewModels.TestViewModel>)Model; // Should be generic! var properties = items.First().GetMetadata().Properties .Where(pm => pm.ShowForDisplay && !ViewData.TemplateInfo.Visited(pm)); %> <table> <tr> <% foreach(var property in properties) { %> <th> <%= property.DisplayName %> </th> <% } %> </tr> <% foreach(var item in items) { %> <tr> <% foreach(var property in properties) { %> <td> <%= Html.Display(property.DisplayName) %> // This doesn't work! </td> <% } %> </tr> <% } %> </table> Two problems with this: I'd like it to be generic. So, I'd like to replace var items = (IQueryable<TestProj.ViewModels.TestViewModel>)Model; with var items = (IQueryable<T>)Model; or something to that effect. The <td> elements are not working because the Html in <%= Html.Display(property.DisplayName) %> contains the model for the view, which is a collection of items, not the item itself. Somehow, I need to obtain an HtmlHelper object whose Model property is the current item, but I'm not sure how to do that. How do I solve these two problems?

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  • Get the selected drop down list value from a FormCollection in MVC

    - by James Santiago
    I have a form posting to an action with MVC. I want to pull the selected drop down list item from the FormCollection in the action. How do I do it? My Html form: <% using (Html.BeginForm()) {%> <select name="Content List"> <% foreach (String name in (ViewData["names"] as IQueryable<String>)) { %> <option value="<%= name %>"><%= name%></option> <% } %> </select> <p><input type="submit" value="Save" /></p> <% } %> My Action: [HttpPost] public ActionResult Index(FormCollection collection) { //how do I get the selected drop down list value? String name = collection.AllKeys.Single(); return RedirectToAction("Details", name); }

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  • Spring MVC - Cannot map request parameters as a Map parameter in method?

    - by Ken Chen
    What I want to do is passing a map to the method in Controller using @RequestParam, but it seems not working. While this is working in Struts 2. Below is what I am trying: In JSP using JQuery: var order = {}; order['seq'] = "ASC"; var criteria = {}; criteria['label'] = "Directory"; $.post(context + 'menu/list', {"orders" : order, "criterias" : criteria} The parameters I am trying to post is an 'map' object order and criteria for listing menu. In Java: @RequestMapping("/{collection}/list") public @ResponseBody Map<String, ? extends Object> list(@PathVariable String collection, @RequestParam("criterias") Map<String, String> criteria, @RequestParam("orders") Map<String, String> order) { However, when I print out the map criteria & order in Java, it takes all value as below: Criteria: {criterias[label]=Directory, orders[seq]=ASC} Order: {criterias[label]=Directory, orders[seq]=ASC} Can @RequestParam in Spring be used to init a Map parameter?

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  • WPF: Binding to ObservableCollection in ControlTemplate is not updated

    - by Julian Lettner
    I created a ControlTemplate for my custom control MyControl. MyControl derives from System.Windows.Controls.Control and defines the following property public ObservableCollection<MyControl> Children{ get; protected set; }. To display the nested child controls I am using an ItemsControl (StackPanel) which is surrounded by a GroupBox. If there are no child controls, I want to hide the GroupBox. Everything works fine on application startup: The group box and child controls are shown if the Children property initially contained at least one element. In the other case it is hidden. The problem starts when the user adds a child control to an empty collection. The GroupBox's visibility is still collapsed. The same problem occurs when the last child control is removed from the collection. The GroupBox is still visible. Another symptom is that the HideEmptyEnumerationConverter converter does not get called. Adding/removing child controls to non empty collections works as expected. Whats wrong with the following binding? Obviously it works once but does not get updated, although the collection I am binding to is of type ObservableCollection. <!-- Converter for hiding empty enumerations --> <Common:HideEmptyEnumerationConverter x:Key="hideEmptyEnumerationConverter"/> <!--- ... ---> <ControlTemplate TargetType="{x:Type MyControl}"> <!-- ... other stuff that works ... --> <!-- Child components --> <GroupBox Header="Children" Visibility="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Children, Converter={StaticResource hideEmptyEnumerationConverter}}"> <ItemsControl ItemsSource="{TemplateBinding Children}"/> </GroupBox> </ControlTemplate> . [ValueConversion(typeof (IEnumerable), typeof (Visibility))] public class HideEmptyEnumerationConverter : IValueConverter { #region IValueConverter Members public object Convert(object value, Type targetType, object parameter, CultureInfo culture) { int itemCount = ((IEnumerable) value).Cast<object>().Count(); return itemCount == 0 ? Visibility.Collapsed : Visibility.Visible; } public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture) { throw new NotImplementedException(); } #endregion } Another, more general question: How do you guys debug bindings? Found this (http://bea.stollnitz.com/blog/?p=52) but still I find it very hard to do. I am glad for any help or suggestion.

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  • Tips for resolving Hibernate/JPA EntityNotFoundException

    - by Damo
    I'm running into a problem with Hibernate where when trying to delete a group of Entities I encounter the following error: javax.persistence.EntityNotFoundException: deleted entity passed to persist: [com.locuslive.odyssey.entity.FreightInvoiceLine#<null>] These are not normally so difficult to track down as they are usually caused by an entity being deleted but not being removed from a Collection that it is a member of. In this case I have removed the entity from every list that I can think of (it's a complex datamodel). I've put JBoss logging into Trace and I can see the collections that are being cascaded. However I can't seem to find the Collection containing the entity that I'm deleting. Does anyone have any tips for resolving this particular Exception? Thanks.

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  • Eclipse standard warning/error overlay icons

    - by pulzar
    I'm writing an Eclipse plug-in... In my custom label decorator, I want to overlay a warning icon, and I'd like to use the standard one used by eclipse (the little yellow triangle). How can I get an image descriptor of this icon? I tried using workbench.getSharedImages().getImageDescriptor(ISharedImages .IMG_DEC_FIELD_WARNING), since that ID seems to match what I'm looking for, but the shared images collection doesn't actually have that image in it (so I just get a null returned). Is there some other shared image collection that I should be looking at?

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  • Sockets server design advice

    - by Rob
    We are writing a socket server in c# and need some advice on the design. Background: Clients (from mobile devices) connect to our server app and we leave their socket open so we can send data back down to them whenever we need to. The amount of data varies but we generally send/receive data from each client every few seconds, so it's quite intensive. The amount of simultaneous connections can range from 50-500 (and more in the future). We have already written a server app using async sockets and it works, however we've come across some stumbling blocks and we need to make sure that what we're doing is correct. We have a collection which holds our client states (we have no socket/connection pool at the moment, should we?). Each time a client connects we create a socket and then wait for them to send us some data and in receiveCallBack we add their clientstate object to our connections dictionary (once we have verified who they are). When a client object then signs off we shutdown their socket and then close it as well as remove them from our collection of clients dictionary. Presumably everything happens in the right order, everything works as expected. However, almost everyday it stops accepting connections, or so we think, either that or it connects but doesn't actually do anything past that and we can't work out why it's just stopping. There are few things that we'r'e unsure about 1) Should we be creating some kind of connection pool as opposed to just a dictionary of client sockets 2) What happens to the sockets that connect but then don't get added to our dictionary, they just linger around in memory doing nothing, should we create ANOTHER dictionary that holds the sockets as soon as they are created? 3) What's the best way of finding if clients are no longer connected? We've read some many methods but we're not sure of the best one to use, send data or read data, if so how? 4) If we loop through the connections dictonary to check for disposed clients, should we be locking the dictionary, if so how does this affect other clients objects trying to use it at the same time, will it throw an error or just wait? 5) We often get disposedSocketException within ReceiveCallBack method at random times, does this mean we are safe to remove that socket from the collection? We can't seem to find any production type examples which show any of this working. Any advice would be greatly received

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  • How to escape HAML for Javascript in Sinatra

    - by viatropos
    I would like to return a list/combobox from an ajax request ("Which on of these do you like?" type thing). I would like to write that little snippet in HAML, which converts it to HTML, but when I do, the page goes blank. I'm assuming this is because the HTML isn't escaped. Is there a way to escape HAML so I can do $("#mydiv").html(response);? Here's the method: post "/something" do # process... haml :"partials/_select", :layout => false, :locals => {:collection => choices} end ... the haml template: %select - collection.each do |item| %option{:value => item.to_s}= item.to_s ... and the javascript: success: function(responseText, statusText, xhr, $form) { $(".dialog_content").append(responseText); } I have tried the sinatra_more plugin and the escape_javascript method, but there's problems with the haml buffer in sinatra. Any ideas?

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  • Advantages of Thread pooling in embedded systems

    - by Microkernel
    I am looking at the advantages of threadpooling design pattern in Embedded systems. I have listed few advantages, please go through them, comment and please suggest any other possible advantages that I am missing. Scalability in systems like ucos-2 where there is limit on number of threads. Increasing capability of any task when necessary like Garbage collection (say in normal systems if garbage collection is running under one task, its not possible to speed it up, but in threadpooling we can easily speed it up). Can set limit on the max system load. Please suggest if I am missing anything.

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  • Linq to SQL problem

    - by Ronnie Overby
    I have a local collection of recordId's (integers). I need to retrieve records that have every one of their child records' ids in that local collection. Here is my query: public List<int> OwnerIds { get; private set; } ... filteredPatches = from p in filteredPatches where OwnerIds.All(o => p.PatchesOwners.Select(x => x.OwnerId).Contains(o)) select p; I am getting this error: Local sequence cannot be used in Linq to SQL implementation of query operators except the Contains() operator. I get that .All() isn't supported by Linq to SQL, but is there a way to do what I am trying to do?

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  • Enum.values() vs EnumSet.allOf( ). Which one is more preferable?

    - by Alexander Pogrebnyak
    I looked under the hood for EnumSet.allOf and it looks very efficient, especially for enums with less than 64 values. Basically all sets share the single array of all possible enum values and the only other piece of information is a bitmask which in case of allOf is set in one swoop. On the other hand Enum.values() seems to be a bit of black magic. Moreover it returns an array, not a collection, so in many cases it must be decorated with Arrays.asList( ) to be usable in any place that expects collection. So, should EnumSet.allOf be more preferable to Enum.values? More specifically, which form of for iterator should be used: for ( final MyEnum val: MyEnum.values( ) ); or for ( final MyEnum val: EnumSet.allOf( MyEnum.values ) );

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  • 'schema' design for a social network

    - by Alan B
    I'm working on a proof of concept app for a twitter style social network with about 500k users. I'm unsure of how best to design the 'schema' should I embed a user's subscriptions or have a separate 'subscriptions' collection and use db references? If I embed, I still have to perform a query to get all of a user's followers. e.g. Given the following user: { "username" : "alan", "photo": "123.jpg", "subscriptions" : [ {"username" : "john", "status" : "accepted"}, {"username" : "paul", "status" : "pending"} ] } to find all of alan's subscribers, I'd have to run something like this: db.users.find({'subscriptions.username' : 'alan'}); from a performance point of view, is that any worse or better than having a separate subscriptions collection? also, when displaying a list of subscriptions/subscribers, I am currently having problems with n+1 because the subscription document tells me the username of the target user but not other attributes I may need such as the profile photo. Are there any recommended practices for such situations? thanks Alan

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  • Ruby types of collections in ActiveRecord

    - by kmorris511
    If I have an object with a collection of child objects in ActiveRecord, i.e. class Foo < ActiveRecord::Base has_many :bars, ... end and I attempt to run Array's find method against that collection: foo_instance.bars.find { ... } I receive: ActiveRecord::RecordNotFound: Couldn't find Bar without an ID I assume this is because ActiveRecord has hijacked the find method for its own purposes. Now, I can use detect and everything is fine. However to satisfy my own curiousity, I attempted to use metaprogramming to explicitly steal the find method back for one run: unbound_method = [].method('find').unbind unbound_method.bind(foo_instance.bars).call { ... } and I receive this error: TypeError: bind argument must be an instance of Array so clearly Ruby doesn't think foo_instance.bars is an Array and yet: foo_instance.bars.instance_of?(Array) -> true Can anybody help me with an explanation of this and of a way to get around it with metaprogramming?

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