string.h

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/*---------------------------------------------------------------------\
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----------------------------------------------------------------------*/
#ifndef ZYPP_NG_CORE_STRING_H_INCLUDED
#define ZYPP_NG_CORE_STRING_H_INCLUDED
 
#include <optional>
#include <zypp-core/base/String.h>
#include <boost/utility/string_view.hpp>
 
namespace zyppng {
 
namespace str {
 
  using zypp::str::Trim;
 
  template <typename T>
  std::optional<T> safe_strtonum ( const std::string_view &val)
  {
    int oerrno = errno;
    errno = 0;  // strtonum/::strtol has no dedicated error-return-code one could check
    const T entryVal = zypp::str::strtonum<T>( val.data() );
    if ( errno == ERANGE )
      return {};
    errno = oerrno;
    return entryVal;
  }
 
  template< typename StrType, typename T = std::remove_reference_t<StrType> >
  T trim( StrType&& s, const Trim trim_r )
  {
    T ret( std::forward<StrType>(s) );
 
    if ( ret.empty() || trim_r == Trim::NO_TRIM )
      return ret;
 
    if ( trim_r & Trim::L_TRIM )
    {
      typename T::size_type p = ret.find_first_not_of( " \t\r\n" );
      if ( p == T::npos )
      {
        if constexpr ( std::is_same_v<std::string_view, StrType> )
          return T();
        else {
          ret.clear();
          return ret;
        }
      }
      ret.remove_prefix( p );
    }
 
    if ( trim_r & Trim::R_TRIM )
    {
      typename T::size_type p = ret.find_last_not_of( " \t\r\n" );
      if ( p == T::npos )
      {
        if constexpr ( std::is_same_v<std::string_view, StrType> )
          return T();
        else {
          ret.clear();
          return ret;
        }
      }
      ret.remove_suffix( ret.size() - ( p+1 ) );
    }
 
    return ret;
  }
 
  template<class TOutputIterator>
  void split( const boost::string_view & line_r, TOutputIterator result_r, const boost::string_view & sepchars_r = " \t", const Trim trim_r = Trim::NO_TRIM )
  {
    //skip initial sepchars
    std::string_view::size_type tokenEnd = 0, tokenBegin = line_r.find_first_not_of( sepchars_r );
 
    //if we do not find a character that is not in sepchars there is nothing to split
    if ( tokenBegin == std::string_view::npos )
      return;
 
    while ( ( tokenEnd = line_r.find_first_of( sepchars_r, tokenBegin ) ) != std::string_view::npos ) {
      auto line = line_r.substr( tokenBegin, tokenEnd-tokenBegin );
      *result_r = trim( line, trim_r );
 
      //find start of next token
      tokenBegin = line_r.find_first_not_of( sepchars_r, tokenEnd );
      if( tokenBegin == std::string_view::npos )
        break;
    }
 
    //insert the final element
    if ( tokenBegin != std::string_view::npos && tokenBegin < line_r.size() )
      *result_r = trim( line_r.substr( tokenBegin ), trim_r );
  }
}
 
  // use strerror from zypp::str in zyppng
  using zypp::str::strerror;
 
}
 
 
#endif