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  • Is there an easy way in Python to wait until certain condition is true?

    - by Checkers
    I need to wait in a script until a certain number of conditions become true? I know I can roll my own eventing using condition variables and friends, but I don't want to go through all the trouble of implementing it, since some object property changes come from external thread in a wrapped C++ library (Boost.Python), so I can't just hijack __setattr__ in a class and put a condition variable there, which leaves me with either trying to create and signal a Python condition variable from C++, or wrap a native one and wait on it in Python, both of which sound fiddly, needlessly complicated and boring. Is there an easier way to do it, barring continuous polling of the condition? Ideally it would be along the lines of res = wait_until(lambda: some_predicate, timeout) if (not res): print 'timed out'

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  • Mapping over multiple Seq in Scala

    - by bsdfish
    Suppose I have val foo : Seq[Double] = ... val bar : Seq[Double] = ... and I wish to produce a seq where the baz(i) = foo(i) + bar(i). One way I can think of to do this is val baz : Seq[Double] = (foo.toList zip bar.toList) map ((f: Double, b : Double) => f+b) However, this feels both ugly and inefficient -- I have to convert both seqs to lists (which explodes with lazy lists), create this temporary list of tuples, only to map over it and let it be GCed. Maybe streams solve the lazy problem, but in any case, this feels like unnecessarily ugly. In lisp, the map function would map over multiple sequences. I would write (mapcar (lambda (f b) (+ f b)) foo bar) And no temporary lists would get created anywhere. Is there a map-over-multiple-lists function in Scala, or is zip combined with destructuring really the 'right' way to do this?

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  • Removing whitespace in Java string?

    - by waitinforatrain
    Hi guys, I'm writing a parser for some LISP files. I'm trying to get rid of leading whitespace in a string. The string contents are along the lines of: :FUNCTION (LAMBDA (DELTA PLASMA-IN-0) (IF (OR (>= #61=(+ (* 1 DELTA) PLASMA-IN-0) 100) (<= #61# 0)) PLASMA-IN-0 #61#)) The tabs are all printed as 4 spaces in the file, so I want to get rid of these leading tabs. I tried to do this: string.replaceAll("\\s{4}", " ") - but it had no effect at all on the string. Does anyone know what I'm doing wrong? Is it because it is a multi-line string? Thanks

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  • What is the best way to set default values in ActiveRecord?

    - by ryw
    What is the best way to set default value in ActiveRecord? I see a post from Pratik that describes an ugly, complicated chunk of code: http://m.onkey.org/2007/7/24/how-to-set-default-values-in-your-model class Item < ActiveRecord::Base def initialize_with_defaults(attrs = nil, &block) initialize_without_defaults(attrs) do setter = lambda { |key, value| self.send("#{key.to_s}=", value) unless !attrs.nil? && attrs.keys.map(&:to_s).include?(key.to_s) } setter.call('scheduler_type', 'hotseat') yield self if block_given? end end alias_method_chain :initialize, :defaults end YUCK! I have seen the following examples googling around: def initialize super self.status = ACTIVE unless self.status end and def after_initialize return unless new_record? self.status = ACTIVE end I've also seen people put it in their migration, but I'd rather see it defined in the model code. What's the best way to set default value for fields in ActiveRecord model?

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  • How to perform multiple find and replace in TextMate besides macro?

    - by T1000
    I have several regular expressions to find and replace text in documents in TextMate. I would like to be able to have them run in a batch. I made a macro and it worked, but any tiny modifications to the macro means re-recording the macro. And I can't seem to modify the regex within the TextMate interface. It's read-only for some reason. Can I make it into a command? Does anyone know how? I tried to read the TextMate help about commands, but it wasn't much help. It seems I need prior knowledge of shell scripts or some sort (which I have none). Any advise in the direction would be great. Thanx in advance.

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  • Is it possible to "learn" a regular expression by user-provided examples?

    - by DR
    Is it possible to "learn" a regular expression by user-provided examples? To clarify: I do not want to learn regular expressions. I want to create a program which "learns" a regular expression from examples which are interactively provided by a user, perhaps by selecting parts from a text or selecting begin or end markers. Is it possible? Are there algorithms, keywords, etc. which I can Google for? EDIT: Thank you for the answers, but I'm not interested in tools which provide this feature. I'm looking for theoretical information, like papers, tutorials, source code, names of algorithms, so I can create something for myself.

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  • Lookup function not working (RS SP2)

    - by Al Reyes
    Hi, I made the upgrade to SP2. I'm trying to use the Lookup function to link data from two different servers. I'm trying first a simple exercise linking data from two datasets from the same server, having one dataset with journals and the other with the account description. My Expression looks like this at a field on the table I have: =Lookup(Fields!ACTINDX.Value,Fields!ACTINDX.Value,Fields!ACTDESCR.Value,"ACCTINFO") I made sure of the names and using only uppercases for datasets and fields but I'm receiving the following message when I try to preview: "An error occurred during local report processing. The definition of the report '/DETAIL' is invalid. The Value expression for the text box 'ACTINDX' refers to the field 'ACTDESCR'. Report item expressions can only refer to fields within the current dataset scope or, if inside an aggregate, the specified dataset scope". I'll appreciate any suggestions. Regards, Al

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  • Replacing elements within a string in R

    - by Maureen
    Hi, I have a row in a data frame in R that is made up of sequences of undetermined length of 0s 1s and 2s as characters. So "01", "010", "201", "102", "00012"... things like this. I'd like to find a way to determine if the last character in the string is NUMERICALLY the largest. It's important that I keep the row in the data frame as characters for other purposes. So basically I want to take substr(x, nchar(x), nchar(x)) and determine if it, as a number, is the largest of the numbers in the character string. I'm super lost as to how to do this, since I'm not all that familiar with regular expressions and I have to back and forth between treating elements as characters and numbers. Thanks in advance. ~Maureen

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  • Is it possible to refactor this C# if(..) statement?

    - by Pure.Krome
    Hi folks, simple question :- i have the following simple if (..) statements :- if (foo == Animal.Cat || foo == Animal.Dog) { .. } if (baa == 1|| baa == 69) { .. } is it possible to refactor these into something like ... DISCLAIMER: I know this doesn't compile .. but this is sorta what i'm trying to get... if (foo == (Animal.Cat || Animal.Dog)) { .. } if (baa == (1 || 69)) { .. } Cheers :) EDIT I wonder if a lambda expression extension could do this? :P

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  • GUID.TryParse() ?

    - by Jack Marchetti
    Obviously there is no public GUID.TryParse() in .NET CLR 2.0. So, I was looking into regular expressions [aka googling around to find one] and each time I found one there was a heated argument in the comments section about RegEx A doesn't work, use RegEx B. Then someone would write Regex C yadda yadda So anyway, What I decided to do was this, but I feel bad about it. public static bool IsGuid (string possibleGuid) { try { Guid gid = new Guid(possibleGuid); return true; } catch (Exception ex) { return false; } } Obviously I don't really like this since it's been drilled into me since day one to avoid throwing exceptions if you can defensibly code around it. Does anyonek now why there is no public Guid.TryParse() in the .NET Framework? Does anyone have a real Regular Expression that will work for all GUIDs?

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  • Storing expression template functors

    - by UncaughtException
    Hello guys, at the moment I'm really interested in expression templates and want to code a library for writing and differentiating mathematical functions with a lambda-style syntax. At the moment, I'm able to write (_x * _x)(2); and get the correct result 4. But I would really like to do something like MathFunction f = _x * _x; f(2);, but I don't have any ideas on how to cope with the recursive expression templates on the right side. Is it possible to achieve this without using the 'auto'-Keyword instead of MathFunction or having to make the operator() virtual? Thanks for your help!

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  • Facebook API - Get comments

    - by Simon R
    Our business has a Facebook Fan Page. The fan page doesn't seem to generate any emails to us when updates are made to the page, whether someone adds a new status or someone comments on one of the statuses etc. Currently, we are running a very crude script to grab the content of the page and then use regular expressions to get the information we require. Obviously this is not fool proof and I'm looking into alternatives to this method. I've been looking at the facebook API and wonder if the rest server might be an option. I cannot, however, seem to find out how to return information of fan page statuses and their comments. Is anyone able to direct me how to use the API to retrieve this information. I am an admin of the fan page. The programming language I'm using is PHP. Many thanks.

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  • algorithmes with no executable example code

    - by gcc
    [link] http://stackoverflow.com/questions/2932016/parsing-of-mathematical-expressions (problem has been told before) ** program is to create the infix tree for the given math expression.** if the expression is given completely paranthesized then the out put is fine but when there are no paranthesis or some part paranthesized then the out put is wrong. cant get the idea how to solve. my problem is told above. I have some algorithm to solve my problem, but I have no simple code which will be guide for me. Can anyone give me simple code (not working code) so that I will try working to understand.(for a 3 hours ,I have been searching and reading some text to understand algorithm which is told above.Actually,there is no example code investigating how it is working. Can anyone send me example which is written in c not other language.

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  • What is the best regular expression for validating email addresses?

    - by acrosman
    Over the years I have slowly developed a regular expression that validates MOST email addresses correctly, assuming they don't use an IP address as the server part. Currently the expression is: ^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$ I use this in several PHP programs, and it works most of the time. However, from time to time I get contacted by someone that is having trouble with a site that uses it, and I end up having to make some adjustment (most recently I realized that I wasn't allowing 4-character TLDs). What's the best regular expression you have or have seen for validating emails? I've seen several solutions that use functions that use several shorter expressions, but I'd rather have one long complex expression in a simple function instead of several short expression in a more complex function.

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  • Vb.Net action delegate problem?

    - by Ramesh Vel
    Hi, Am vb.net newbie. This question might be very novice and answered before, but i couldn't find. I was trying the lambda features and got struck here. Private Function HigerOrderTest(highFunction as Func(Of Int16,Int16)) As Action(of String) Dim sam = highFunction(3) Dim DoIt as Action(of String) DoIt = sub(s) console.WriteLine(s) return DoIt End Function I got "Expression expected." at line DoIt = sub(s) console.WriteLine(s). And when i changed this to DoIt = function(s) console.WriteLine(s) i got Expression does not produce a value. error. Whats the problem? Cheers

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  • Linq To SQL: Retain list order when using .Contains

    - by rockinthesixstring
    I'm using Lucene.net to build a MyListOfIds As List(Of Integer) which I then pass on to my Linq service. I then search the database as follows Return _EventRepository.Read().Where(Function(e) MyListOfIds.Contains(e.ID)).ToList Now I know that Lucene is already ordering MyListOfIds based on the weight it gave each term. What sucks is that Linq is losing that order in it's SQL search. My Question: How can I retain that sort order when building my Lambda expression? I tried using LINQPad to see how the query is being built, but because I had to declare a variable LINQPad didn't show me the resultant SQL :-( Here's what I tried in LINQPad Dim i As New List(Of Integer) i.Add(1) i.Add(100) i.Add(15) i.Add(3) i.Add(123) Dim r = (From e In Events Where i.Contains(e.ID) Select e) note: my example is in VB.NET, but I don't mind if responses are in C#

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  • Safely dereferencing FirstOrDefault call in Linq c#

    - by samy
    For brevity's sake in my code, i'd like to be able to do the following: having a collection, find the first element matching a lambda expression; if it exists, return the value of a property or function. If it doesn't exist, return null. var stuff = {"I", "am", "many", "strings", "obviously"}; var UpperValueOfAString = stuff.FirstOrDefault(s => s.contains("bvi")).ToUpper(); // would return "OBVIOUSLY" var UpperValueOfAStringWannabe = stuff.FirstOrDefault(s => s.contains("unknown token")).ToUpper(); // would return null Is it possible with some linq-syntax-fu or do i have to check explicitly for the return value before proceeding?

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  • Using Where method in Linq 2 Entities with OR clause.

    - by Dani
    I want to use Where method in Linq 2 entities that will be equal to this userRepository.Users.Where(u=>u.RoleID == 1 || u=>u.RoldID == 2).Select(o => new SelectListItem { Text = o.Role.RoleName, Value = o.RoleID.ToString() }).ToList(); The problem of course is in Where(u=u.RoleID == 1 || u=u.RoldID == 2) The problem is that I don't know how to use WHERE method with OR inside the WHERE clause. any ideas (the code above will not compile of-course b/c of the lambda expression. userRepository.Users returns an list of Users entities. I guess that and can be done using concatenation of .Where().Where() but I need an OR.

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  • How do I bind a key to "the function represented by the following key sequence"?

    - by katrielalex
    I'm just starting to learn emacs (woohoo!) and I've been mucking around in my .emacs quite happily. Unfortunately, I don't know Lisp yet, so I'm having issues with the basics. I've already remapped a few keys until I fix my muscle memory: (global-set-key (kbd "<f9>") 'recompile) That's fine. But how can I tell a key to 'simulate pressing several keys'? For instance, I don't know, make <f1> do the same as C-u 2 C-x } (widen buffer by two chars). One way is to look up that C-x } calls shrink-window-horizontally, and do some sort of lambda thing. This is of course the neat and elegant way (how do you do this?). But surely there's a way to define <f1> to send the keystrokes C-u 2 C-x }?

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  • Semantic errors

    - by gautam kumar
    Can semantic errors be detected by the compiler or not? If not when do the errors get detected? As far as I know semantic errors are those errors which result from the expressions involving operators with incorrect number/type of operands. For example: n3=n1*n2;//n1 is integer, n2 is a string, n3 is an integer The above statement is semantically incorrect. But while reading C Primer Plus by Stephen Prata I found the following statement The compiler does not detect semantic errors, because they don't violate C rules. The compiler has no way of divining your true intentions. That leaves it to you to find these kinds of errors. One way is to compare what a program does to what you expected it to do. If not the compiler, who detects those errors? Am I missing something?

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  • deploying a war to tomcat using python

    - by Decado
    Hi, I'm trying to deploy a war to a Apache Tomcat server (Build 6.0.24) using python (2.4.2) as part of a build process. I'm using the following code import urllib2 import base64 war_file_contents = open('war_file.war','rb').read() username='some_user' password='some_pwd' base64string = base64.encodestring('%s:%s' % (username, password))[:-1] authheader = "Basic %s" % base64string opener = urllib2.build_opener(urllib2.HTTPHandler) request = urllib2.Request('http://158.155.40.110:8080/manager/deploy?path=war_file', data=war_file_contents) request.add_header('Content-Type', 'application/octet-stream') request.add_header("Authorization", authheader) request.get_method = lambda: 'PUT' url = opener.open(request) the url.code is 200, and the url.msg is "OK". However the web archive doesn't appear on the manager list applications page. Thanks.

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  • Express XPath as an expression tree

    - by 47d_
    If I have an XPath query like NodeA/NodeB[@WIDTH and not(@WIDTH="20")] | NodeC[@WIDTH and not(@WIDTH="20")]/NodeD Is there any API available to visualize this XPath query as a stack of atomic expressions, something like (following is generic) Get results of NodeA, call it "first set" Get results of NodeB from "first set" Filter where [@WIDTH and not(@WIDTH="20")] Filter NodeD, call this "node d for B" Get results of NodeC from "first set" Filter where [@WIDTH and not(@WIDTH="20")] Filter NodeD, call this "node d for C" Combine "node d for B" and "node d for C" I am trying to see if we can convert the XPath expression into custom expression which is close to english and vice versa. If no API is available, what would be the best approach? Thanks in advance.

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  • Efficient way to organise data file in columns with Python

    - by user1700959
    I'm getting an output data file of a program which looks like this, with more than one line for each time step: 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 7.9819E-06 1.7724E-02 2.3383E-02 3.0048E-02 3.8603E-02 4.9581E-02 5.6635E-02 4.9991E-02 3.9052E-02 3.0399E-02 .... I want to arrange it in ten columns I have made a Python script, using regular expressions to delete \n in the proper lines, but I think that there should be a simpler more elegant way to do it, here is my script: import re with open('inputfile', encoding='utf-8') as file1: datai=file1.read() dataf=re.sub(r'(?P<nomb>( \d\.\d\d\d\dE.\d\d){8})\n','\g<nomb>',datai) with open('result.txt',mode='w',encoding='utf-8') as resultfile: resultfile.write(datof) Thanks in advance

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  • Java - Reg. Ex. File Question

    - by aloh
    I'm grabbing lines from a text file and sifting line by line using regular expressions. I'm trying to search for blank lines, meaning nothing or just whitespace. However, what exactly is empty space? I know that whitespace is \s but what is a line that is nothing at all? null (\0)? newline (\n)? I tried the test harness in the Java tutorial to try and test to see what an empty space is but no luck so far.

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  • Sed substitution not doing what I want and think it should do

    - by nategoose
    I have am trying to use sed to get some info that is encoded within the path of a file which is passed as a parameter to my script (Bourne sh, if it matters). From this example path, I'd like the result to be 8 PATH=/foo/bar/baz/1-1.8/sing/song I first got the regex close by using sed as grep: echo $PATH | sed -n -e "/^.*\/1-1\.\([0-9][0-9]*\).*/p" This properly recognized the string, so I edited it to make a substitution out of it: echo $PATH | sed -n -e "s/^.*\/1-1\.\([0-9][0-9]*\).*/\1/" But this doesn't produce any output. I know I'm just not seeing something simple, but would really appreciate any ideas about what I'm doing wrong or about other ways to debug sed regular expressions.

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