method-missing

问题 I have been playing around with the dynamic abilities of powershell and I was wondering something Is there is anything in powershell analogous to Ruby's method_missing() where you can set up a 'catch all method' to dynamically handle calls to non-existant methods on your objects? 回答1: No, not really. I suspect that the next version of PowerShell will become more in line with the dynamic dispatch capabilities added to .NET 4 but for the time being, this would not be possible in pure PowerShell

问题 When I invoke a method that doesn't exist, method_missing will tell me the name of the method. When I attempt to access a variable that hasn't been set, the value is simply nil . I'm attempting to dynamically intercept access to nil instance variables and return a value based on the name of the variable being accessed. The closest equivalent would be PHP's __get. Is there any equivalent functionality in Ruby? 回答1: I do not believe this is possible in Ruby. The recommended way would be to use

问题 similar to the one in Ruby 回答1: The following is no longer strictly true with the Dynamic trait found in [experimental] Scala 2.9. See the answer from Kipton Barros, for example. However, Dynamic is still not quite like method_missing , but rather employs compiler magic to effectively rewrite method calls to "missing" methods, as determined statically, to a proxy ( applyDynamic ). It is the approach of statically-determining the "missing" methods that differentiates it from method_missing

问题 similar to the one in Ruby 回答1: The following is no longer strictly true with the Dynamic trait found in [experimental] Scala 2.9. See the answer from Kipton Barros, for example. However, Dynamic is still not quite like method_missing , but rather employs compiler magic to effectively rewrite method calls to "missing" methods, as determined statically, to a proxy ( applyDynamic ). It is the approach of statically-determining the "missing" methods that differentiates it from method_missing

问题 Scenario: -bash-3.2$ irb -f ruby-1.9.3-p0 :001 > @v = {} => {} ruby-1.9.3-p0 :002 > def method_missing(sym, *args); @v[sym]; end => nil ruby-1.9.3-p0 :003 > a (irb):2: stack level too deep (SystemStackError) -bash-3.2$ I ran with -f to avoid loading any irbrc stuff. I'm expecting to get nil when I input a . What's going on, and is there a workaround? I tried wrapping a with a begin / rescue Exception block but that didn't do anything. This also happens with 1.9.2, but not 1.9.1. More strange

问题 Ruby has method_missing , Python has getattr . Does Boo offer something I can use to intercept method calls? 回答1: Yes, Boo has IQuackFu. Basically, you implement IQuackFu , which has three methods: QuackGet : gets called when you get a property value QuackSet gets called when you set a property value QuackInvoke : gets called when you invoke a method Here's an example. 来源： https://stackoverflow.com/questions/1147641/how-can-i-intercept-a-method-call-in-boo

问题 This is a repost on another issue, better isolated this time. In my environment.rb file I changed this line: config.time_zone = 'UTC' to this line: config.active_record.default_timezone = :utc Ever since, this call: Category.find(1).subcategories.map(&:id) Fails on "Stack level too deep" error after the second time it is run in the development environment when config.cache_classes = false. If config.cache_classes = true, the problem does not occur. The error is a result of the following code

问题 I have a data set in which the variable GENDER containing two levels Male(M) and Female(F) has lot of Missing values . How do i deal with missing value? What are the different methods to handle these missing values. Any help would be appreciated. 回答1: There are several techniques in order to estimate a missing value. I've been writing a paper for a project at Uni regarding such methods. I will briefly explain 5 commonly used missing data imputation techniques. Hereinafter we will consider a

问题 I have a data set in which the variable GENDER containing two levels Male(M) and Female(F) has lot of Missing values . How do i deal with missing value? What are the different methods to handle these missing values. Any help would be appreciated. 回答1: There are several techniques in order to estimate a missing value. I've been writing a paper for a project at Uni regarding such methods. I will briefly explain 5 commonly used missing data imputation techniques. Hereinafter we will consider a

问题 I am using Slick2D to code a little game, and after a lot of time that already went into it, I changed my mind and decided that I indeed want the game to be resizable. So I tried to use the app.setResizable() command, as suggested on the Slick2D wiki (and here: How to make slick2d resizable). But my eclipse just didnt find that method, so I looked it up on the Internet again, and noticed that all attributes and methods reliative to resizing are missing (such as wasResized(), isResized(),