Task: Rosetta Code_Rank languages by popularity


C++: #include <string>
#include <boost/regex.hpp>
#include <boost/asio.hpp>
#include <vector>
#include <utility>
#include <iostream>
#include <sstream>
#include <cstdlib>
#include <algorithm>
#include <iomanip>

struct Sort { 
   bool operator( ) ( const std::pair<std::string,int> & a , const std::pair<std::string,int> & b ) 
      const {
	 return a.second > b.second ;
      }
} ;

int main( ) {
   try {
      
      boost::asio::io_service io_service ; 
      boost::asio::ip::tcp::resolver resolver ( io_service ) ;
      boost::asio::ip::tcp::resolver::query query ( "rosettacode.org" , "http" ) ;
      boost::asio::ip::tcp::resolver::iterator endpoint_iterator = resolver.resolve( query ) ;
      boost::asio::ip::tcp::resolver::iterator end ;
      boost::asio::ip::tcp::socket socket( io_service ) ;
      boost::system::error_code error = boost::asio::error::host_not_found ;
      
      while ( error && endpoint_iterator != end ) {
	 socket.close( ) ;
	 socket.connect( *endpoint_iterator++ , error ) ;
      }
      if ( error ) 
	 throw boost::system::system_error ( error ) ;
      
      boost::asio::streambuf request ;
      std::ostream request_stream( &request ) ;
      request_stream << "GET " << "/mw/index.php?title=Special:Categories&limit=5000" << " HTTP/1.0\r\n" ;
      request_stream << "Host: " << "rosettacode.org" << "\r\n" ;
      request_stream << "Accept: */*\r\n" ;
      request_stream << "Connection: close\r\n\r\n" ;
      
      boost::asio::write( socket , request ) ;
      
      boost::asio::streambuf response ;
      std::istream response_stream ( &response ) ;
      boost::asio::read_until( socket , response , "\r\n\r\n" ) ;
      boost::regex e( "<li><a href=\"[^<>]+?\">([a-zA-Z\\+#1-9]+?)</a>\\s?\\((\\d+) members\\)</li>" ) ;
      
      std::ostringstream line ;
      std::vector<std::pair<std::string , int> > languages ; 
      boost::smatch matches ;
      while ( boost::asio::read( socket , response , boost::asio::transfer_at_least( 1 ) , error ) ) {
	 line << &response ;
	 if ( boost::regex_search( line.str( ) , matches , e ) ) {
	    std::string lang( matches[2].first , matches[2].second ) ;
	    int zahl = atoi ( lang.c_str( ) ) ;
	    languages.push_back( std::make_pair( matches[ 1 ] , zahl ) ) ;
	 }
	 line.str( "") ;
      }
      if ( error != boost::asio::error::eof ) 
	 throw boost::system::system_error( error ) ;
      
      std::sort( languages.begin( ) , languages.end( ) , Sort( ) ) ;
      int n = 1 ;
      for ( std::vector<std::pair<std::string , int> >::const_iterator spi = languages.begin( ) ;
	    spi != languages.end( ) ; ++spi ) {
	 std::cout << std::setw( 3 ) << std::right << n << '.' << std::setw( 4 ) << std::right <<  
	 spi->second   << " - " << spi->first << '\n' ;
	 n++ ;
      }
   } catch ( std::exception &ex ) {
      std::cout << "Exception: " << ex.what( ) << '\n' ;
   }
   return 0 ;
}










Ada: with Ada.Integer_Text_IO;   use Ada.Integer_Text_IO;
with Ada.Strings.Fixed;     use Ada.Strings.Fixed;
with Ada.Strings.Unbounded; use Ada.Strings.Unbounded;
with Ada.Text_IO;           use Ada.Text_IO;

with Ada.Containers.Ordered_Sets;
with Ada.Strings.Less_Case_Insensitive;

with AWS.Client;
with AWS.Response;

procedure Test is

   use Ada.Strings;

   function "+" (S : String) return Unbounded_String renames To_Unbounded_String;

   type A_Language_Count is
      record
         Count    : Integer := 0;
         Language : Unbounded_String;
      end record;

   function "=" (L, R : A_Language_Count) return Boolean is
   begin
      return L.Language = R.Language;
   end "=";

   function "<" (L, R : A_Language_Count) return Boolean is
   begin
      
      return L.Count < R.Count
        or else (L.Count = R.Count
                 and then Less_Case_Insensitive (Left  => To_String (L.Language),
                                                 Right => To_String (R.Language)));
   end "<";

   package Sets is new Ada.Containers.Ordered_Sets (A_Language_Count);
   use Sets;

   Counts : Set;

   procedure Find_Counts (S : String) is
      Title_Str : constant String  := "title=""Category:";
      End_A_Str : constant String  := "</a> (";

      Title_At   : constant Natural := Index (S, Title_Str);
   begin
      if Title_At /= 0 then
         declare
            Bracket_At : constant Natural := Index (S (Title_At   + Title_Str'Length .. S'Last), ">");
            End_A_At   : constant Natural := Index (S (Bracket_At + 1                .. S'Last), End_A_Str);
            Space_At   : constant Natural := Index (S (End_A_At   + End_A_Str'Length .. S'Last), " ");
            Count      : constant Natural := Natural'Value (S (End_A_At + End_A_Str'Length .. Space_At - 1));
            Language   : constant String  :=                S (Title_At + Title_Str'Length .. Bracket_At - 2);
         begin
            if Bracket_At /= 0 and then End_A_At /= 0 and then Space_At /= 0 then
               begin
                  Counts.Insert (New_Item => (Count, +Language));
               exception
                  when Constraint_Error =>
                     Put_Line (Standard_Error, "Warning: repeated language: " & Language);
                     
                     null;
               end;
            end if;
            
            Find_Counts (S (Space_At + 1 .. S'Last));
         end;
      end if;

   end Find_Counts;

   Place : Natural := 1;

   procedure Display (C : Cursor) is
   begin
      Put (Place, Width => 1);             Put (". ");
      Put (Element (C).Count, Width => 1); Put (" - ");
      Put_Line (To_String (Element (C).Language));
      Place := Place + 1;
   end Display;
 
   Http_Source : constant AWS.Response.Data :=
     AWS.Client.Get ("http://rosettacode.org/mw/index.php?title=Special:Categories&limit=5000");
begin
   Find_Counts (AWS.Response.Message_Body (Http_Source));
   Counts.Reverse_Iterate (Display'Access);
end Test;