wildcardmatcher.hpp

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//==================================================================================================
/// \file
/// This header file is part of module \alib_strings of the \aliblong.
///
/// \emoji :copyright: 2013-2024 A-Worx GmbH, Germany.
/// Published under \ref mainpage_license "Boost Software License".
//==================================================================================================
#ifndef HPP_ALIB_STRINGS_UTIL_WILDCARDMATCHER
#define HPP_ALIB_STRINGS_UTIL_WILDCARDMATCHER 1
#pragma once
#include "alib/strings/cstring.hpp"
#include <vector>
 
namespace alib {  namespace strings { namespace util  {
 
//==================================================================================================
/// This utility class implements so called <em>wildcard string matching</em>. Wildcard characters
/// are
/// -  <c>'*'</c>: Matches zero or more characters.
/// -  <c>'?'</c>: Matches exactly one character.
///
/// Method #Compile accepts the pattern string and translates it to an internal (simple) list of
/// "matching commands". This way, the class is optimized for performance, because after compilation,
/// subsequent invocations of #Match do not need to parse the pattern string.
///
/// @tparam TChar    The character type. Implementations for \c nchar and \c wchar are provided
///                  with type definitions \ref alib::WildcardMatcherN and
///                  \ref alib::WildcardMatcherW.
//==================================================================================================
template<typename TChar>
class TWildcardMatcher
{
        /// The result list of commands created with #Compile and executed with #Match.
        std::vector<std::pair<int,TString<TChar>>>  commands;
 
    public:
        //==========================================================================================
        /// Constructs a WildcardMatcher to work on a given string. Passes the optional parameters
        /// to method #Compile.
        ///
        /// @param  pattern      The string pattern to match.
        ///                      Defaults to \b NULL_STRING to allow parameterless construction,
        ///                      with later invocation of #Compile.
        //==========================================================================================
        TWildcardMatcher( const TString<TChar>& pattern= NULL_STRING )
        {
            Compile( pattern );
        }
 
    public:
        //==========================================================================================
        /// Resets this object to use the given pattern.
        ///
        /// @param  pattern      The string pattern to match.
        //==========================================================================================
        ALIB_API
        void Compile( const TString<TChar>& pattern );
 
        //==========================================================================================
        /// Tests if given \p{haystack} matches the actual pattern.
        /// If #Compile was not invoked or an empty pattern string was given, \c true is returned.
        ///
        /// @param haystack     The string to test.
        /// @param sensitivity  Denotes whether the matching is performed case-sensitive.
        ///                     Defaults to \c %Case::Sensitive.
        /// @return \c true if given \p{haystack} matches the actual pattern, \c false otherwise.
        //==========================================================================================
        ALIB_API
        bool   Match( const TString<TChar>& haystack, lang::Case sensitivity = lang::Case::Sensitive  );
 
}; // class WildcardMatcher
 
 
extern template ALIB_API void TWildcardMatcher<nchar>::Compile( const TString<nchar>& );
extern template ALIB_API bool TWildcardMatcher<nchar>::Match  ( const TString<nchar>&, lang::Case );
extern template ALIB_API void TWildcardMatcher<wchar>::Compile( const TString<wchar>& );
extern template ALIB_API bool TWildcardMatcher<wchar>::Match  ( const TString<wchar>&, lang::Case );
 
}} // namespace alib[::strings::util]
 
/// Type alias in namespace \b alib.
using     WildcardMatcher=     strings::util::TWildcardMatcher<character>;
 
/// Type alias in namespace \b alib.
using     WildcardMatcherN=    strings::util::TWildcardMatcher<nchar>;
 
/// Type alias in namespace \b alib.
using     WildcardMatcherW=    strings::util::TWildcardMatcher<wchar>;
 
} // namespace [alib]
 
#endif // HPP_ALIB_STRINGS_UTIL_WILDCARDMATCHER