regexsubstitution.cpp

里面有很多关于编程的实用例子

// Fig. 21.5: RegexSubstitution.cpp
// Using regex_replace algorithm.
#include <iostream>
using std::cout;
using std::endl;

#include <string>
using std::string;

#include "boost/regex.hpp"

int main()
{
   // create the test strings
   string testString1 = "This sentence ends in 5 stars *****";
   string testString2 = "1, 2, 3, 4, 5, 6, 7, 8";
   string output;

   cout << "Original string: " << testString1 << endl;

   // replace every * with a ^
   testString1 = 
      boost::regex_replace( testString1, boost::regex( "\\*" ), "^" );
   cout << "^ substituted for *: " << testString1 << endl;

   // replace "stars" with "carets"
   testString1 = boost::regex_replace(
      testString1, boost::regex( "stars" ), "carets" );
   cout << "\"carets\" substituted for \"stars\": " 
      << testString1 << endl;

   // replace every word with "word"
   testString1 = boost::regex_replace(
      testString1, boost::regex( "\\w+" ), "word" );
   cout << "Every word replaced by \"word\": " << testString1 << endl;

   // replace the first three digits with "digit"
   cout << "\nOriginal string: " << testString2 << endl;
   string testString2Copy = testString2;

   for ( int i = 0; i < 3; i++ ) // loop three times
   {
      testString2Copy = boost::regex_replace( testString2Copy,
         boost::regex( "\\d" ), "digit", boost::format_first_only );
   } // end for

   cout << "Replace first 3 digits by \"digit\": " 
      << testString2Copy << endl;

   // split the string at the commas
   cout << "string split at commas [";

   boost::sregex_token_iterator tokenIterator( testString2.begin(),
      testString2.end(), boost::regex( ",\\s" ), -1 ); // token iterator
   boost::sregex_token_iterator end; // empty iterator

   while (  tokenIterator != end ) // tokenIterator isn't empty
   {
      output += "\"" + *tokenIterator + "\", "; // add the token to output
      tokenIterator++; // advance the iterator
   } // end while

   // delete the ", " at the end of output string
   cout << output.substr( 0, output.length() - 2 ) << "]" << endl;

   return 0;
} // end of function main

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