search for: backreference

I appears that backreferences when using regexes in node names doesn''t work. Can anyone confirm this? If I''m incorrect, how do I go about using a backreference to the name regex within the node definition container? Thanks, Guy -- You received this message because you are subscribed to the Google Groups...

Hi I have a problem with substitutions involving named backreferences. I have a vector American.dates: > American.dates [1] "5/15/1976" "2.15.1970" "1.9.2006" which I want to change into British.dates: > British.dates [1] "15/5/1976" "15/2/1970" "9/1/2006" I know I can do it like this: British.da...

Hi, I'm running out of the *numbered* backreferences \\1, \\2, ..., \\9 for gsub(). Does R support *named* backreferences, and if so, what is the syntax? Thanks Henrik

Hi Folks, I'm trying to extract just the backreferences from a regex. > temp = "abcd1234abcd1234" > regmatches(temp, gregexpr("(?:abcd)(1234)", temp)) [[1]] [1] "abcd1234" "abcd1234" What I would like is: [1] "1234" "1234" Note: I know I can just match 1234 here, but the actual exampl...

...I already have it in my branches and can provide a full implementation with tests (FileCheck now has a test/ dir all of its own since r168113) if the proposal is accepted. The rough outline of the implementation: To enable such matching in a natural way, our regex implementation needs to support backreferences in matches. This then allows to find all references to a variable defined on the same line and substitute them by backrefs. Luckily, our regex implementation already supports backreferences, although a bit of hacking is required to enable it. It supports both Basic Regular Expressions (BREs) and...

I have a matching problem that I cant solve. mystring = "xxx{XX}yy{YYY}zzz{Z}" where "x","X","y","Y","z","Z" basiclly can be anything, letters, digits etc. I'm only interested in the content within each "{}". I am close but not really there yet. library(gsubfn) strapply(mystring,"\\{[^\\}]+",, perl=F)

...e to do something like this: string.gsub(regexp, output(''\0'' ,''\1'', ''\2'') Output returns a string. I tested it in irb and it worked ok. Now when it''s in my application, the ''\1'' and others don''t resolve as backreferences to the matches as they should. How can I fix this? Or go around it? -- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this g...

I'm having a Thursday morning mental block, any suggestions on the following would be most appreciated... I have (as an example) surgery = c("d48", "d67", "dnc37", "a75", "d10", "a78", "d31", "d55", "d1") before each number part the possibilities are c("a", "d",

You can either use positive lookahead/lookbehind - but support for that is a bit flaky. Or write a proper regex, and use backreferences to keep what you need. R > x <- "abc 1,1 ,1 1, x,y 2,3 " R > gsub("(\\d),(\\d)", "\\1.\\2", x, perl = TRUE) [1] "abc 1.1 ,1 1, x,y 2.3 " B. > On Feb 12, 2018, at 9:34 PM, Jim Lemon <drjimlemon at gmail.com> wrote: > > Hi Denni...

...'s fault). A pathalogical example that I _have_ encountered due to temp file naming on Windows: > badpath <- "foo\\2\\bar" > root <- "c:\\HERE\\file.txt" > gsub("HERE", badpath, root) Error in gsub("HERE", badpath, root) : invalid backreference 2 in regular expression Using file.path is recommended as a best practice, but AFAICT, it forces "\" on Windows. Why not have file.path dynamically read .Platform$file.sep so that in code that uses file.path one could modify .Platform$file.sep and change the behavior of all subsequent...

gsubfn is a package with one function, gsubfn, that is like gsub except instead of taking a replacement string it takes a replacement function. For each match, that match is passed to the replacement function along with the backreferences, if any, and replaced with the output of the function. If the first two arguments are omitted the defaults are set to do perl-style (sort of) string interpolation as in last example. gsubfn is available for all platforms via CRAN. # makes all letters except first in word lower case # output: &qu...

Hello, I would like to have a function that retrieve matching strings in the same way as with java.util.regex (java 1.4.2). Example: f('^.*(xx?)\\.([0-9]*)$','abcxx.785') => c('xx','785') First of all: Is it possible to achiev this with grep(... perl=TRUE,value=TRUE )? As I would call this function very often with large data, I'm reluctant to use Sjava

Hi all, I swear this used to work: library(gsubfn) strapply("S(AC,P)TVDK(8)EELVQK(8), ".[(].{1,2}[)]|.")[[1]] But somewhere along the update path it stopped ... now giving me this Error in base::gsub(pattern, rs, x, ...) : invalid backreference 2 in regular expression Can't figure it out. What am I doing wrong? Thanks for any hints, Joh

gsubfn is a package with one function, gsubfn, that is like gsub except instead of taking a replacement string it takes a replacement function. For each match, that match is passed to the replacement function along with the backreferences, if any, and replaced with the output of the function. If the first two arguments are omitted the defaults are set to do perl-style (sort of) string interpolation as in last example. gsubfn is available for all platforms via CRAN. # makes all letters except first in word lower case # output: &qu...

...lass="inlinepage"> <div class="toggleableend"> foo </div> </div> It renders it as follows: <div class="inlinepage"> <div class="toggleableend"> foo </div> <p></div></p> The problem is that it uses a backreference in the expression that it passes to gen_extract_tagged, which is broken when Text::Balanced wraps it in parentheses. The attached patch fixes it. -- Matt -------------- next part -------------- --- Markdown.pl.orig 2006-08-29 19:11:53.000000000 -0700 +++ Markdown.pl 2007-05-02 00:28:53.000000000...

Download: <http://daringfireball.net/projects/downloads/Markdown_1.0.2b8.tbz> Changes from 1.0.2b7: + Fixed bug with nested raw HTML tags that contained attributes. The problem is that it uses a backreference in the expression that it passes to gen_extract_tagged, which is broken when Text::Balanced wraps it in parentheses. Thanks to Matt Kraai for the patch. + Now supports URLs containing literal parentheses, such as: http://en.wikipedia.org/wiki/WIM...

Hi, I am looking for a way to extract an "interesting" part of the match to a regular expression. For example the pattern "[./](*.)" matches a substring that begins with either "." or "/" followed by anything. I am interested in this "anything" w/o the "." or "/" prefix. If say I match the pattern against "abc/foo" I

...brary" pkg = "c:\\falcon\\abind_1.1-0.zip" install.packages(pkg, repos=NULL, lib=badLib) package 'abind' successfully unpacked and MD5 sums checked updating HTML package descriptions Error in gsub("^URL: ../../../library", lib0, readLines(cfile)) : invalid backreference 2 in regular expression After looking at src/library/utils/R/windows/linkhtml.R, it seems the error is that the "\\2" part of the path is interpreted by gsub as a back reference. Changing "\\" to "/" in the library path fixes this issue: > okLib = chartr(&quot...

Dear all-- I am still forging my first arms with R and I am fighting with regexpr() as well as portability between unix and windoz. I need to extract barcodes from filenames (which are located between a double and single underscore) as well as the directory where the filename is residing. Here is the solution I came to: aFileName <-

...and can provide a > full implementation with tests (FileCheck now has a test/ dir all of > its own since r168113) if the proposal is accepted. > > The rough outline of the implementation: > > To enable such matching in a natural way, our regex implementation > needs to support backreferences in matches. This then allows to find > all references to a variable defined on the same line and substitute > them by backrefs. > > Luckily, our regex implementation already supports backreferences, > although a bit of hacking is required to enable it. It supports both > Basic Re...