search for: metaprogram

Hello, Say I want to make a multiple regression model with the following expression: lm(y~x1 + x2 + x3 + ... + x_n,data=mydata) It gets boring to type in the whole independent variables, in this case x_i. Is there any simple way to do the metaprogramming for this? (There are different cases where the names of the independent variables might sometimes have apparent patterns or not)

Chris Lattner <clattner at apple.com> writes: > The problem that I have with this sort of higher order metaprogramming Metaprogramming? This isn't template metaprogramming if that's what you mean. > in C++'98 is that you're trading one set of complexity for another. What's the other complexity? -Dave

Hi all, I''m trying to move a bunch of methods out of a controller into a library that I can include and call a class method to have it dynamically add a bunch of methods to the controller. The goal is to just add to each controller: include UIEnhancements::SubList sub_list ''Note'', ''incomplete'' and have the sub_list method create all the methods

For edge rails there is a Crud generator. There is also a CRUD controller that is out there from which you can inherit your other controllers (see http://geekonomics.blogspot.com/2006/07/crud-and- shared-controllers.html) This got me thinking about Crud controllers in general. As far as I know, the generator can''t produce crud classes which are nested (i.e.

Chris Lattner <clattner at apple.com> writes: > On Jul 15, 2011, at 12:35 PM, David Greene wrote: > >> I've run into a use case where I'd like to use a mapped_iterator to >> iterator the 1st (or 2nd) items in a sequence of std::pairs. Does >> select1st/select2nd exist somewhere within LLVM or is there some >> equivalent? If not, I'll add it. >

...but it results in a lot of code duplication when moving > DagInit to a uniqued pool implementation. I wanted to put the > processing code in a third function which would be called with various > types of iterators over those vectors. The problem that I have with this sort of higher order metaprogramming in C++'98 is that you're trading one set of complexity for another. Please just introduce a helper function or something and duplicate the loop. -Chris

I always need to apply alternating item styles when outputting a collection, here''s what I''ve been using recently. In the app helper I define this method: def alternate(items,alt=false items.map{|i| i.class}.each { |k| k.class_eval {attr_accessor :alt}} items.each { |i| i.alt, alt = alt, !alt } end When I call the partial I wrap the collection with this method:

Hello, I felt annoyed enough when having to redirect user back to their previous location in a hackish way that I wrote this plugin. It avoids storing POST and Ajax request. It also has a facility to specify actions not to store in the history. If you are interested, it''s there: http://blog.cosinux.org/pages/rails-history See you all, Damien -- Damien MERENNE

In HAML I have hundreds of lines like the following: - xyz = someFuncThatReturnsString(''xyz'') and elsewhere %div{''id'' => xyz} The above lines work fine. - - - Attempting to keep things DRY (Don''t repeat yourself) I want to do something like - eval(otherFuncThatReturnsString(''xyz'')) where

I'm talking about mapped iterator + select1st. -Chris On Jul 16, 2011, at 2:58 PM, greened at obbligato.org (David A. Greene) wrote: > Chris Lattner <clattner at apple.com> writes: > >> The problem that I have with this sort of higher order metaprogramming > > Metaprogramming? This isn't template metaprogramming if that's what you > mean. > >> in C++'98 is that you're trading one set of complexity for another. > > What's the other complexity? > > -Dave

...ey can capture things like unique_ptr<> and still be moved off the stack 2) making @property declarations work with move-only types like unique_ptr<> 3) enabling std::weak_ptr<> to weakly store an objc pointer under ARC. (see radar: 31177975) 4) add a mechanism to allow template metaprogramming to make full use of selectors. (see radar: 30812297)

Hey fellows, I am a novice to ruby and ror, but really addicted to it. As a graduate student, I need master thesis topic around Ruby aor ROR. Can anyone suggest some for me? Regards/Buyan -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to

URLS http://rubyforge.org/projects/codeforpeople/ http://codeforpeople.com/lib/ruby/traits ABOUT traits.rb is set of attr_* like methods on steroids, caffeine, and botox. it encourages better living through meta-programming and uniform access priciples. traits.rb supports smart inheritence of class attributes and a fistful of hooks for veryifying and munging attr values.

i''m using method_missing to implement a simple metaprogramming that checks for account rights. in Account << ActiveRecord::Base i defined: def method_missing(m, a = {}) if m.to_s =~ /^has_right_(.*)$/ ... calls another method passing $1 parameter end end it seems to override some of the active record methods based on method missing. in the c...

...instance with me. After this record is saved I want an after_save callback which would print the id of the record. The only catch is that I am not allowed to change the User class. How can I accomplish my goal? Is that even possible to add an after_save callback on a particular instance object. Any metaprogramming hack. I''m sure ruby does provide some tool. This would be a trivial issue if I were allowed to change the User class but I am not. -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email t...

...e, I hate having to force a choice between "convenience to implementor of an API to just take a StringRef" vs "convenience to client of API for it to take a Twine". It really stinks. I was chatting with Howard Hinnant about this and he suggested replacing Twine with a template metaprogramming expression-template system. I haven't thought through all the details, but perhaps this would allow us to get the best of both worlds? > Hmm, this is one bit I'm not sure about. As I tried to explain above, > it seems problematic to have to choose your argument type on the basis...

...dev policy or preference around C-style casts versus C++-style casts? Twine is littered with the former but I generally use the latter for safety/clarity of intend, etc. (I'm not going to try to fix everything in Twine just now if we're considering alternative implementations like template metaprogramming anyway) >> As a side note on Twine's design: Is there a particular reason it uses >> void*s rather than unions? > > I'm not sure what you're proposing specifically. I've attached an version of my fix that includes the union use I was referring to (sorry for b...

This has been in the news lately, so I wrote up an article about a method I use to protect my app against XSS attacks. It''s easy to use if you don''t care how it works, and I go through some of the metaprogramming techniques I used if you do. Check it out: http://blog.explorationage.com/articles/2006/01/25/how-to-protect-your-rails-apps-against-cross-site-scripting-attacks Justin

...things like unique_ptr<> and still be moved off the stack > 2) making @property declarations work with move-only types like unique_ptr<> > 3) enabling std::weak_ptr<> to weakly store an objc pointer under ARC. (see radar: 31177975) > 4) add a mechanism to allow template metaprogramming to make full use of selectors. (see radar: 30812297) > _______________________________________________ > LLVM Developers mailing list > llvm-dev at lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev

Dear R-devel, There is a new feature in R-devel, which explicitly refers to LISP @ operator for splicing. > The backquote function bquote() has a new argument splice to enable splicing a computed list of values into an expression, like ,@ in LISP's backquote. Although the most upvoted SO question asking for exactly LISP's @ functionality in R doesn't seems to be addressed by this