Search Results

Search found 5968 results on 239 pages for 'generator expression'.

Page 16/239 | < Previous Page | 12 13 14 15 16 17 18 19 20 21 22 23  | Next Page >

  • Implementing "Generator" support in a custom language

    - by Roger Alsing
    I've got a bit of fettish for language design and I'm currently playing around with my own hobby language. (http://rogeralsing.com/2010/04/14/playing-with-plastic/) One thing that really makes my mind bleed is "generators" and the "yield" keyword. I know C# uses AST transformation to transform enumerator methods into statemachines. But how does it work in other languages? Is there any way to get generator support in a language w/o AST transformation? e.g. Does languages like Python or Ruby resort to AST transformations to solve this to? (The question is how generators are implemented under the hood in different languages, not how to write a generator in one of them)

    Read the article

  • Create a color generator in matplotlib

    - by Brendan
    I have a series of lines that each need to be plotted with a separate colour. Each line is actually made up of several data sets (positive, negative regions etc.) and so I'd like to be able to create a generator that will feed one colour at a time across a spectrum, for example the gist_rainbow map shown here. I have found the following works but it seems very complicated and more importantly difficult to remember, from pylab import * NUM_COLORS = 22 mp = cm.datad['gist_rainbow'] get_color = matplotlib.colors.LinearSegmentedColormap.from_list(mp, colors=['r', 'b'], N=NUM_COLORS) ... # Then in a for loop this_color = get_color(float(i)/NUM_COLORS) Moreover, it does not cover the range of colours in the gist_rainbow map, I have to redefine a map. Maybe a generator is not the best way to do this, if so what is the accepted way?

    Read the article

  • Navigation properties not set when using ADO.NET Mocking Context Generator

    - by olenak
    I am using ADO.NET Mocking Context Generator plugin for my Entity Framework model. I have not started on using mocks yet, just trying to fix generated entity and context classes to make application run as before without exceptions. I've already fixed T4 template to support SaveChanges method. Now I've got another problem: when I try to access any navigation property it is set to null. All the primitive fields inherited from DB table are set and correct. So what I am doing is the following using (var context = MyContext()) { var order = context.Orders.Where(p => p.Id == 7); var product = order.Products; } in this case product is set to null. But that was not a case while using default code generator, it used to return real product object. Thanks ahead for any suggestions!

    Read the article

  • Could not find generator mini_test:install

    - by David James
    I expected these generators to be available: $ rails g Usage: rails generate GENERATOR [args] [options] MiniTest: mini_test:controller mini_test:helper mini_test:install mini_test:mailer mini_test:model mini_test:scaffold So I ran: $ rails g mini_test:install But got this error: Could not find generator mini_test:install. As for my environment, here is the relevant portion of my Gemfile: group :test, :development do gem 'minitest-rails' end And the resulting portions of my Gemfile.lock: minitest (2.12.1) minitest-rails (0.0.7) minitest (~> 2.12) rails (~> 3.1) I am now in the process of debugging this. I would appreciate any tips. In any case, I will report back.

    Read the article

  • Python configuration file generator

    - by Stan
    I want to use Python to make a configuration file generator. My roughly idea is feeding input with template files and some XML files with the real settings. Then use the program to generate the real configuration files. I got several questions: Is there any open source configuration generator program? (what could be the keyword), I wonder if there's anything can be added/modified in the design. Does Python have good XML parser module? Is it good idea to use XML file to save the original settings? I've been thinking to use Excel since it's more intuitive to maintain, but harder for program to parse. Not sure how people deal with this. Hope the community can give me some suggestions. Thanks a lot!

    Read the article

  • Converting a Linq expression tree that relies on SqlMethods.Like() for use with the Entity Framework

    - by JohnnyO
    I recently switched from using Linq to Sql to the Entity Framework. One of the things that I've been really struggling with is getting a general purpose IQueryable extension method that was built for Linq to Sql to work with the Entity Framework. This extension method has a dependency on the Like() method of SqlMethods, which is Linq to Sql specific. What I really like about this extension method is that it allows me to dynamically construct a Sql Like statement on any object at runtime, by simply passing in a property name (as string) and a query clause (also as string). Such an extension method is very convenient for using grids like flexigrid or jqgrid. Here is the Linq to Sql version (taken from this tutorial: http://www.codeproject.com/KB/aspnet/MVCFlexigrid.aspx): public static IQueryable<T> Like<T>(this IQueryable<T> source, string propertyName, string keyword) { var type = typeof(T); var property = type.GetProperty(propertyName); var parameter = Expression.Parameter(type, "p"); var propertyAccess = Expression.MakeMemberAccess(parameter, property); var constant = Expression.Constant("%" + keyword + "%"); var like = typeof(SqlMethods).GetMethod("Like", new Type[] { typeof(string), typeof(string) }); MethodCallExpression methodExp = Expression.Call(null, like, propertyAccess, constant); Expression<Func<T, bool>> lambda = Expression.Lambda<Func<T, bool>>(methodExp, parameter); return source.Where(lambda); } With this extension method, I can simply do the following: someList.Like("FirstName", "mike"); or anotherList.Like("ProductName", "widget"); Is there an equivalent way to do this with Entity Framework? Thanks in advance.

    Read the article

  • Efficient (basic) regular expression implementation for streaming data

    - by Brendan Dolan-Gavitt
    I'm looking for an implementation of regular expression matching that operates on a stream of data -- i.e., it has an API that allows a user to pass in one character at a time and report when a match is found on the stream of characters seen so far. Only very basic (classic) regular expressions are needed, so a DFA/NFA based implementation seems like it would be well-suited to the problem. Based on the fact that it's possible to do regular expression matching using a DFA/NFA in a single linear sweep, it seems like a streaming implementation should be possible. Requirements: The library should try to wait until the full string has been read before performing the match. The data I have really is streaming; there is no way to know how much data will arrive, it's not possible to seek forward or backward. Implementing specific stream matching for a couple special cases is not an option, as I don't know in advance what patterns a user might want to look for. For the curious, my use case is the following: I have a system which intercepts memory writes inside a full system emulator, and I would like to have a way to identify memory writes that match a regular expression (e.g., one could use this to find the point in the system where a URL is written to memory). I have found (links de-linkified because I don't have enough reputation): stackoverflow.com/questions/1962220/apply-a-regex-on-stream stackoverflow.com/questions/716927/applying-a-regular-expression-to-a-java-i-o-stream www.codeguru.com/csharp/csharp/cs_data/searching/article.php/c14689/Building-a-Regular-Expression-Stream-Search-with-the-NET-Framework.htm But all of these attempt to convert the stream to a string first and then use a stock regular expression library. Another thought I had was to modify the RE2 library, but according to the author it is architected around the assumption that the entire string is in memory at the same time. If nothing's available, then I can start down the unhappy path of reinventing this wheel to fit my own needs, but I'd really rather not if I can avoid it. Any help would be greatly appreciated!

    Read the article

  • LINQ to SQL: NOTing a prebuilt expression

    - by ck
    I'm building a library of functions for one of my core L2S classes, all of which return a bool to allow checking for certain situations. Example: Expression<Func<Account, bool>> IsSomethingX = a => a.AccountSupplementary != null && a.AccountSupplementary.SomethingXFlag != null && a.AccountSupplementary.SomethingXFlag.Value; Now to query where this is not true, I CAN'T do this: var myAccounts= context.Accounts .Where(!IsSomethingX); // does not compile However, using the syntax from the PredicateBuilder class, I've come up with this: public static IQueryable<T> WhereNot<T>(this IQueryable<T> items, Expression<Func<T, bool>> expr1) { var invokedExpr = Expression.Invoke(expr1, expr1.Parameters.Cast<Expression>()); return items.Where(Expression.Lambda<Func<T, bool>> (Expression.Not(invokedExpr), expr1.Parameters)); } var myAccounts= context.Accounts .WhereNot(IsSomethingX); // does compile which actually produces the correct SQL. Does this look like a good solution, and is there anything I need to be aware of that might cause me problems in future?

    Read the article

  • Evaluate cron expression

    - by Jake A. Smith
    Is there a command line tool that will simply evaluate a cron expression and return a bool response if it is supposed to be running right now? I'm looking for something I can use as a utility in another bash script. Something like so: run_script=$(/tools/evaluate-cron-expression "02 4 * * *") if [ "$run_script" -eq "1" ] # etc etc I know, I know, I could just setup a real cron job, but I'm playing with the idea of wrapping all of my scheduled scripts inside of another script.

    Read the article

  • Notepad ++ regular expression

    - by arvindwill
    have javascript file will millions of lines. The problem is IE dont support ','(comma) followed by '}'(curly close bracket) by using notepadd++ need to find all the comma which is followed by curly close bracket. So regular expression \,.*\} works. but the problem between the comma and close bracket many tab space or newline or linefeed can be there . cant able to provide the newline with spaces in regular expression. like below one somestring, }

    Read the article

  • Can I use relative XPath expressions in libxml2?

    - by brbr
    I am wondering whether it is possible to use relative XPath expressions in libxml2. This is from the javax.xml.xpath API and I would like to do the similar thing using libxml2: Node widgetNode = (Node) xpath.evaluate(expression, document, XPathConstants.NODE); With a reference to the element, a relative XPath expression can now written to select the child element: XPath xpath = XPathFactory.newInstance().newXPath(); String expression = "manufacturer"; Node manufacturerNode = (Node) xpath.evaluate(expression, **widgetNode**, XPathConstants.NODE);

    Read the article

  • What is the easiest way to get the property value from a passed lambda expression in an extension me

    - by Andrew Siemer
    I am writing a dirty little extension method for HtmlHelper so that I can say something like HtmlHelper.WysiwygFor(lambda) and display the CKEditor. I have this working currently but it seems a bit more cumbersome than I would prefer. I am hoping that there is a more straight forward way of doing this. Here is what I have so far. public static MvcHtmlString WysiwygFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression) { return MvcHtmlString.Create(string.Concat("<textarea class=\"ckeditor\" cols=\"80\" id=\"", expression.MemberName(), "\" name=\"editor1\" rows=\"10\">", GetValue(helper, expression), "</textarea>")); } private static string GetValue<TModel, TProperty>(HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression) { MemberExpression body = (MemberExpression)expression.Body; string propertyName = body.Member.Name; TModel model = helper.ViewData.Model; string value = typeof(TModel).GetProperty(propertyName).GetValue(model, null).ToString(); return value; } private static string MemberName<T, V>(this Expression<Func<T, V>> expression) { var memberExpression = expression.Body as MemberExpression; if (memberExpression == null) throw new InvalidOperationException("Expression must be a member expression"); return memberExpression.Member.Name; } Thanks!

    Read the article

  • New regular expression features in PCRE 8.34 and 8.35

    - by Jan Goyvaerts
    PCRE 8.34 adds some new regex features and changes the behavior of a few to make it better compatible with the latest versions of Perl. There are no changes to the regex syntax in PCRE 8.35. \o{377} is now an octal escape just like \377. This syntax was first introduced in Perl 5.12. It avoids any confusion between octal escapes and backreferences. It also allows octal numbers beyond 377 to be used. E.g. \o{400} is the same as \x{100}. If you have any reason to use octal escapes instead of hexadecimal escapes then you should definitely use the new syntax. Because of this change, \o is now an error when it doesn’t form a valid octal escape. Previously \o was a literal o and \o{377} was a sequence of 337 o‘s. In free-spacing mode, whitespace between a quantifier and the ? that makes it lazy or the + that makes it possessive is now ignored. In Perl this has always been the case. In PCRE 8.33 and prior, whitespace ended a quantifier and any following ? or + was seen as a second quantifier and thus an error. The shorthand \s now matches the vertical tab character in addition to the other whitespace characters it previously matched. Perl 5.18 made the same change. Many other regex flavors have always included the vertical tab in \s, just like POSIX has always included it in [[:space:]]. Names of capturing groups are no longer allowed to start with a digit. This has always been the case in Perl since named groups were added to Perl 5.10. PCRE 8.33 and prior even allowed group names to consist entirely of digits. [[:<:]] and [[::]] are now treated as POSIX-style word boundaries. They match at the start and the end of a word. Though they use similar syntax, these have nothing to do with POSIX character classes and cannot be used inside character classes. Perl does not support POSIX word boundaries. The same changes affect PHP 5.5.10 (and later) and R 3.0.3 (and later) as they have been updated to use PCRE 8.34. RegexBuddy and RegexMagic have been updated to support the latest versions of PCRE, PHP, and R. Older versions that were previously supported are still supported, so you can compare or convert your regular expressions between the latest versions of PCRE, PHP, and R and whichever version you were using previously.

    Read the article

  • How to perform regular expression based replacements on files with MSBuild

    - by Daniel Cazzulino
    And without a custom DLL with a task, too . The example at the bottom of the MSDN page on MSBuild Inline Tasks already provides pretty much all you need for that with a TokenReplace task that receives a file path, a token and a replacement and uses string.Replace with that. Similar in spirit but way more useful in its implementation is the RegexTransform in NuGet’s Build.tasks. It’s much better not only because it supports full regular expressions, but also because it receives items, which makes it very amenable to batching (applying the transforms to multiple items). You can read about how to use it for updating assemblies with a version number, for example. I recently had a need to also supply RegexOptions to the task so I extended the metadata and a little bit of the inline task so that it can parse the optional flags. So when using the task, I can pass the flags as item metadata as follows:...Read full article

    Read the article

  • Regular Expression HTML tags

    - by user134615
    I'd like to know whether it exists a way to put the following HTML tags in a regex. What I want is a regex that can match all the start tags with their corresponding closing tags. E.g., Hello There might be more tags inside. I had thought of something like this: ^<([a-z]+)([^<]+)(?:(.)</\1|\s+/)$/, but it wont work. Sorry if this question doesnt belong to this section. Thank you.

    Read the article

  • If Expression True in Immediate Window But Code In if Block Never Runs

    - by Julian
    I set a break point in my code in MonoDevelop to break whenever I click on a surface. I then enter the immediate window and test to see if the the if statement will return true in comparing two Vector3's. It does return true. However, when I step over, the code is never run as though the statement evaluated false. Does anyone know how this could be possible? I've attached a screenshot. Here is the picture of my debug window and immediate window. You can see where the immediate window evaluates to true. The second breakpoint is not hit. Here are the details of the two Vector3's I am comparing. Does anyone know why I am experiencing this? It really seems like an anomaly to me :/ Does it have something to do with threading?

    Read the article

  • Google Analytics Funnel Step Regular Expression Not Working

    - by scoarescoare
    The first step in a funnel is going to have a dynamic ending fragment. Examples: http://mysite.com/invite/tickle-party http://mysite.com/invite/pajama-party http://mysite.com/invite/puppy-party To allow for such dynamism, I provided this url for step one: \invite(.*) My goals work but the funnel visualization report shows 0 for everything. I know this problem is due to the regex in the funnel step because I copied this entire goal except I replaced \invite(.*) with /invite/puppy-party When I hardcoded /invite/puppy-party the funnel worked as expected. Why is my funnel report not working with my original funnel step url parameter?

    Read the article

< Previous Page | 12 13 14 15 16 17 18 19 20 21 22 23  | Next Page >