Is there a way to repeat the capture an arbitrary number of times in a regex?
I am using C ++ tr1 :: regex with ECMA regex grammar. What I'm trying to do is to parse the title and return the values associated with each element in the title.
Title:
-Testing some text
-Numbers 1 2 5
-MoreStuff some more text
-Numbers 1 10
What I would like to do is find all "-Numbers" strings and put each number into its own result with one regex. As you can see, "-Numbers" strings can have any number of values per string. Currently I am just looking for "-Numbers ([\ s0-9] +)" and then symbolizing this result. I was just wondering if there is a way to find and highlight the results in a single regex.
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I was about to ask this same question and I found a solution.
Let's say you have an arbitrary number of words that you want to capture.
"there are four lights"
and
"Captain Picard is the bomb"
You might think that the solution is:
/((\w+)\s?)+/
But this will only match the entire input line and the last captured group.
What you can do is use the "g" switch.
So an example in Perl:
use strict;
use warnings;
my $str1 = "there are four lights";
my $str2 = "captain picard is the bomb";
foreach ( $str1, $str2 ) {
my @a = ( $_ =~ /(\w+)\s?/g );
print "captured groups are: " . join( "|", @a ) . "\n";
}
Output:
captured groups are: there|are|four|lights
captured groups are: captain|picard|is|the|bomb
So there is a solution if your language of choice supports the "g" equivalent (and I think most of them ...).
Hope this helps someone who was in the same position as me!
S
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The problem is that the desired solution insists on using capture groups. C ++ provides a tool regex_token_iterator
for better management (C ++ example):
#include <iostream>
#include <string>
#include <regex>
using namespace std;
int main() {
std::regex e (R"((?:^-Numbers)?\s*(\d+))");
string input;
while (getline(cin, input)) {
std::regex_token_iterator<std::string::iterator> a{
input.begin(), input.end(),
e, 1,
regex_constants::match_continuous
};
std::regex_token_iterator<std::string::iterator> end;
while (a != end) {
cout << *a << " - ";
++a;
}
cout << '\n';
}
return 0;
}
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