July 2006 - Boost-users - lists.preview.boost.org

seeking a better way of regex replacing!
by llwaeva＠21cn.com 30 Jul '06

30 Jul '06

Hi there, boost:regex is powerful in string replacing. I am working with a complicate case which need a faster method in replacing substring. Here is my problem. I have a big string contains some pattern %K{xxx}, where xxx is a filename which may vary from place to place. e.g. BIG_STRING = ... ... %K{abc.txt} ... ... ... ... %K{foo.ini} ... ... OK, what complicated is that: I must retrieve the filename from %K{xxx}, load the content of the file and then replace %K{xxx} with the content. I search the code with a loop string::const_iterator start, end; string filename, content; boost::regex re("%K\\{(.*)\\}"); boost::match_results<std::string::const_iterator> what; boost::match_flag_type flags = boost::match_default; start = BIG_STRING.begin(); end = BIG_STRING.end(); while ( regex_search(start, end, what, re, flags) ) { if (what[1].first!=what[1].second) { filename = string(what[1].first, what[1].second); } content = LoadFile(filename); // transform the const_iterator to iterator string::iterator sbegin(BIG_STRING.begin()), send(BIG_STRING.begin()); std::advance(sbegin, distance<string::const_iterator>(sbegin, what[0].first)); std::advance(send, distance<string::const_iterator>(send, what[0].second)); // replace the content BIG_STRING.replace( sbegin, send, content ); // reset the current position of the source string to search the next pattern start = what[1].second; // I copy the code from the document of boost, don't know what the following code for flags |= boost::match_prev_avail; flags |= boost::match_not_bob; } The second approach is to retrieve the filename and load the content seperately, build the substitute format and replace all the patterns with replace_all_regex, e.g. string& escape_format( string& input ) { replace_all( input, "$", "$$" ); replace_all( input, "\\", "\\\\" ); replace_all( input, ":", "\\:" ); replace_all( input, "?", "\\?" ); replace_all( input, "(", "\$" ); replace_all( input, ")", "\$" ); return input; } stringstream reformat; string regex_text; int n=0; while ( regex_search(start, end, what, re, flags) ) { if (what[1].first!=what[1].second) { filename = string(what[1].first, what[1].second); } content = LoadFile(filename); regex_text += string(what[0].first, what[0].second); reformat << "(?" << ++n << " " << escape_format( content ) << ")"; // reset the current position of the source string to search the next pattern start = what[1].second; // I copy the code from the document of boost, don't know what the following code for flags |= boost::match_prev_avail; flags |= boost::match_not_bob; } // replace the whole string at last replace_all_regex( BIG_STRING, boost::regex(regex_text), reformat.str(), format_all ); But this approach cause exception!!! Any better idea for my problem? Thanks in advance.

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BOOST_CHECK problem!
by 袁晓辉 30 Jul '06

30 Jul '06

The doc says "It(BOOST_CHECK) also increments an error count<http://www.boost.org/libs/test/doc/components/minimal_testing/index.html>", but it seems not: #include <boost/test/included/unit_test_framework.hpp> using boost::unit_test::test_suite; void test1() { BOOST_CHECK(false); } test_suite* init_unit_test_suite( int, char* [] ) { test_suite* test= BOOST_TEST_SUITE( "Unit test ); test->add( BOOST_TEST_CASE( &test1), 1); return test; } Output: ----------------------------------------------------- Running 1 test case... xxx.cpp(171): error in "test1": check false failed *** No errors detected ----------------------------------------------------- ps. I am using boost-1_33_1.

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replace_all_regex help
by llwaeva＠21cn.com 30 Jul '06

30 Jul '06

Hi there, I wrote a piece of code to handle MIME header based on boost. The program subsitite the MIME header (from, to, subject, etc.) into a template with specific macro. Because the macro may occur everywhere in the template once or more, so I apply replace_all_regex. First of all, I need to transform the substitute string to escape special characters // input is a substitute string that will replace the macro string& escape_format( string& input ) { replace_all( input, "$", "$$" ); replace_all( input, "\\", "\\\\" ); replace_all( input, ":", "\\:" ); replace_all( input, "?", "\\?" ); replace_all( input, "(", "\$" ); replace_all( input, ")", "\$" ); return input; } There are some macros definied, some of them are listed below %s represents the subject (e.g. Re: hi philip!) %S represents the subject without prefix "Re:" (e.g hi philip!) %f represents the "form" (e.g. tom(a)hotmail.com) %t represents the "to" (e.g. philip(a)hotmail.com) ... With regex, I can replace all the macros with the help of format, something like replace_all_regex( source, boost::regex("(%f)|(%t)|(%s)|(%S)"), "(?1 xxx)(?2 yyy)(?3 aaa)(?4 bbb)", format_all ); In order to get the subject without prefix "Re:", I use erase_regex as follow string& deRe(string& input) { boost::regex regexp("^[[:space:]]*Re:[[:space:]]*"); erase_regex( input, regexp ); return input; } So simple!!! However, the order and number of macro will be changed sometimes. So I need a better way to build regex and format. I've got a function to do that // rformat is a stringstream for building a format // text is a substitute string // re_text is a string for building a regular expression // re is a string or regular expression, i.e. the macro // format_num is an global integer to hold the current number of format items (initialize to zero) void format_text(stringstream& rformat, string& text, string& re_text, const string& re) { format_num++; rformat << "(?" << format_num << " " << escape_format(text) << ")"; if (format_num>1) re_text += "|"; re_text += "(" + re + ")"; } Now, it's ready to build the regular expression and subsitiude formation dynamically. Here is an example, string regex_text; stringstream reformat; string source; // source is a string containing text and macros // spHeader is char* which is obtained from MIME parser. // if (spHeader) { format_text( reformat, string(spHeader), regex_text, "%s" ); // for %s format_text( reformat, deRe(string(spHeader)), regex_text, "%S" ); // for %S // Suppose spHeader is "Re: hi philp!", then // regex_text = "(%s)|(%S)" // reformat.str() = "(?1 Re: hi philip!)(?2 hi philip!)" replace_all_regex( source, boost::regex(regex_text), reformat.str(), format_all ); } Everything is fine except that there are some meaningless characters at the end of the output string (still source). By checking the code carefully, I found that the problem maybe caused by the format_text for %S. Hiding the second format_text solve the problem. However, just hiding the first format_text also solve the problem. It is confusing me! Someone please give me a direction. Thanks.

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[Regex]Converting from old style to new style
by John Grabner 29 Jul '06

29 Jul '06

I used to be able to write this : void LineTracker::Analyse(const std::string &Buffer) { std::string::const_iterator start, end; start = Buffer.begin(); end = Buffer.end(); boost::regex_grep(std::bind1st(std::mem_fun(&LineTracker::grep_callback), this), start, end, expression); } to get the regex to call back into my class. With the change to the new style using iterator I can do this. void LineTracker::Analyse(const std::string &Buffer) { boost::sregex_iterator m1(Buffer.begin(), Buffer.end(), expression); boost::sregex_iterator m2; std::for_each(m1, m2, *this); } However for_each makes a copy of my class, so at the end it does not update the current instance with the results. What do I need to do to have the the current instance receive the call back from regex? John.

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Re: [Boost-users] Problem with boost::multi_index
by JOAQUIN LOPEZ MU?Z 29 Jul '06

29 Jul '06

René ha escrito: > Joaquín ha escrito: > > * What happens if you fully qualify mem_fun, i.e. if > you write ::boost::multi_index::mem_fun? > > Well, when I tried this option it worked! > > It looks like gcc missed the "using boost::multi_index" > declaration. > > In order to gain experience: If you have any idea what > was the problem it will be appreciated. Not really :( Maybe the compiler gets confused by the presence of the template function std::mem_fun (does your "Item.h" explicitly or implicitly include <functional>?), but this is only a wild guess. In any case, this is a compiler bug, likely to solve if you upgrade your GCC copy. Sorry I can't give a more conclusive answer. > Thanks again. > > René Good luck with your project, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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[mpl] Collapsing sequences of integer constants
by Eric Lemings 29 Jul '06

29 Jul '06

Greetings, I'm trying to come up with an algorithm that will "collapse" a sequence of integer constants by adding like elements together. For example, typedef vector_c< int, 1,1,1,3,5,5,7,10,10 > input; would become: typedef vector_c< int, 3, 3, 10, 7, 20 > result; You can assume the sequence is already sorted. Would appreciate any tips. Thanks, Eric.

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Re: [Boost-users] Problem with boost::multi_index
by JOAQUIN LOPEZ MU?Z 28 Jul '06

28 Jul '06

Rene Tarantino wrote: > Hi : > > I'm just starting to use boost utility library and it > seems very promising. I am trying to define a new > multi_index type and gcc it's giving me error messages. > > First I properly added the includes for boost::multi_index : > > #include <boost/multi_index_container.hpp> > #include <boost/multi_index/mem_fun.hpp> > #include <boost/multi_index/hashed_index.hpp> > > then the includes for "Item" and "ObjectId" declarations: > > #include "Item.h" > > following that appears this: > > typedef multi_index_container< > Item*, > indexed_by< > hashed_unique<mem_fun<Item, ObjectId, &Item::getId> > > > > > ItemsContainer; > > When I try to compile this code gcc reports the following errors: > > error: 'mem_fun' was not declared in this scope > error: template argument 1 is invalid > error: type/value mismatch at argument 3 in template parameter > list for 'template<class Arg1, class Arg2, class Arg3, class Arg4> > struct boost::multi_index::hashed_unique' > error: expected a type, got '&emedia::lumiere::Item::getId' > error: template argument 1 is invalid > error: template argument 2 is invalid > error: expected unqualified-id before '>' token > > It seems that I'm forgetting something. It's very strange because > all ready compilled this code in another project but I can't find > any difference with this one. Hello René, I really can't reproduce the problem you describe. The attached file tries to mimic your scenario (with a dummy Item definition) and here everything works OK. Could you please try it in your environment? I guess the problem is not in what you describe, but in what you don't, I mean, sorrounding details that you're taking for granted. Things to check: * Are you using some using directive? Which one? * Are you doing some funny thing with the "mem_fun" identifier inside "Item.h"? * What happens if you fully qualify mem_fun, i.e. if you write ::boost::multi_index::mem_fun? I hope some of the above rings a bell for you. Please report back. Best, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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Problem with boost::multi_index
by Rene Tarantino 28 Jul '06

28 Jul '06

Hi : I'm just starting to use boost utility library and it seems very promising. I am trying to define a new multi_index type and gcc it's giving me error messages. First I properly added the includes for boost::multi_index : #include <boost/multi_index_container.hpp> #include <boost/multi_index/mem_fun.hpp> #include <boost/multi_index/hashed_index.hpp> then the includes for "Item" and "ObjectId" declarations: #include "Item.h" following that appears this: typedef multi_index_container< Item*, indexed_by< hashed_unique<mem_fun<Item, ObjectId, &Item::getId> > > > ItemsContainer; When I try to compile this code gcc reports the following errors: error: 'mem_fun' was not declared in this scope error: template argument 1 is invalid error: type/value mismatch at argument 3 in template parameter list for 'template<class Arg1, class Arg2, class Arg3, class Arg4> struct boost::multi_index::hashed_unique' error: expected a type, got '&emedia::lumiere::Item::getId' error: template argument 1 is invalid error: template argument 2 is invalid error: expected unqualified-id before '>' token It seems that I'm forgetting something. It's very strange because I all ready compilled this code in another project but I can't find any difference with this one. Any idea. Thanks in advance. René

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[license] Why is the Boost license not an official Open Source license?
by Stephen Toledo-Brown 28 Jul '06

28 Jul '06

I'm wondering why the Boost license is not listed at http://www.opensource.org/licenses/index.html (And is there any idea to submit it for inclusion there?)

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Question about program_options
by Drumheller, Michael 28 Jul '06

28 Jul '06

Regarding boost::program_options: I would like to parse (and then store) some command-line options that potentially contain unregistered flags, and I understand from <<http://www.boost.org/doc/html/program_options/howto.html#id2716386>> that the way to do this is: basic_command_line_parser<char> parser(argc, argv); basic_parsed_options<char> parsed(parser.options(options).allow_unregistered().run()); Indeed this works--for parsing. But how do I store the resulting parsed options (in a way that ignores the unregistered ones)? Simply calling store(parsed, vm); throws a boost::program_options::unknown_option exception. I can take the (brute force) step of erasing from parsed.options all elements for which the unregistered attribute is true, and then calling store(parsed, vm). That seems to work, but it so clumsy that it makes me think I'm using the system in a way that was not intended. Can anyone help? Thank you. MD P.S. There is a bug in the doc: "collect_arguments(...)" on the last line of the above link should be collect_unrecognized(...); similarly, in the source code parsers.hpp (line 158) there is a mention of the nonexistent function "collect_unregistered"). Michael Drumheller Boeing Phantom Works Mathematics and Engineering Analysis 425.865.3520 michael.drumheller(a)boeing.com This email may contain proprietary information. If you are not the intended recipient please delete it and notify the sender that you received it in error.

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