text: /*
   * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #pragma once
  
  #include <AK/Forward.h>
  #include <AK/RefPtr.h>
  #include <AK/Stream.h>
  #include <AK/StringImpl.h>
  #include <AK/StringUtils.h>
  #include <AK/Traits.h>
  
  namespace AK {
  
  // String is a convenience wrapper around StringImpl, suitable for passing
  // around as a value type. It's basically the same as passing around a
  // RefPtr<StringImpl>, with a bit of syntactic sugar.
  //
  // Note that StringImpl is an immutable object that cannot shrink or grow.
  // Its allocation size is snugly tailored to the specific string it contains.
  // Copying a String is very efficient, since the internal StringImpl is
  // retainable and so copying only requires modifying the ref count.
  //
  // There are three main ways to construct a new String:
  //
  //     s = String("some literal");
  //
  //     s = String::format("%d little piggies", m_piggies);
  //
  //     StringBuilder builder;
  //     builder.append("abc");
  //     builder.append("123");
  //     s = builder.to_string();
  
  class String {
  public:
      using ConstIterator = const char*;
  
      ~String() { }
  
      String() { }
      String(const StringView&);
  
      String(const String& other)
          : m_impl(const_cast<String&>(other).m_impl)
      {
      }
  
      String(String&& other)
          : m_impl(move(other.m_impl))
      {
      }
  
      String(const char* cstring, ShouldChomp shouldChomp = NoChomp)
          : m_impl(StringImpl::create(cstring, shouldChomp))
      {
      }
  
      String(const char* cstring, size_t length, ShouldChomp shouldChomp = NoChomp)
          : m_impl(StringImpl::create(cstring, length, shouldChomp))
      {
      }
  
      explicit String(ReadonlyBytes bytes, ShouldChomp shouldChomp = NoChomp)
          : m_impl(StringImpl::create(bytes, shouldChomp))
      {
      }
  
      String(const StringImpl& impl)
          : m_impl(const_cast<StringImpl&>(impl))
      {
      }
  
      String(const StringImpl* impl)
          : m_impl(const_cast<StringImpl*>(impl))
      {
      }
  
      String(RefPtr<StringImpl>&& impl)
          : m_impl(move(impl))
      {
      }
  
      String(NonnullRefPtr<StringImpl>&& impl)
          : m_impl(move(impl))
      {
      }
  
      String(const FlyString&);
  
      static String repeated(char, size_t count);
      bool matches(const StringView& mask, CaseSensitivity = CaseSensitivity::CaseInsensitive) const;
  
      Optional<int> to_int() const;
      Optional<unsigned> to_uint() const;
  
      String to_lowercase() const;
      String to_uppercase() const;
  
      enum class TrimMode {
          Left,
          Right,
          Both
      };
      String trim_whitespace(TrimMode mode = TrimMode::Both) const;
  
      bool equals_ignoring_case(const StringView&) const;
  
      bool contains(const String&) const;
      Optional<size_t> index_of(const String&, size_t start = 0) const;
  
      Vector<String> split_limit(char separator, size_t limit, bool keep_empty = false) const;
      Vector<String> split(char separator, bool keep_empty = false) const;
      String substring(size_t start, size_t length) const;
  
      Vector<StringView> split_view(char separator, bool keep_empty = false) const;
      StringView substring_view(size_t start, size_t length) const;
  
      bool is_null() const { return !m_impl; }
      ALWAYS_INLINE bool is_empty() const { return length() == 0; }
      ALWAYS_INLINE size_t length() const { return m_impl ? m_impl->length() : 0; }
      ALWAYS_INLINE const char* characters() const { return m_impl ? m_impl->characters() : nullptr; }
  
      ALWAYS_INLINE ReadonlyBytes bytes() const { return m_impl ? m_impl->bytes() : nullptr; }
  
      ALWAYS_INLINE const char& operator[](size_t i) const
      {
          return (*m_impl)[i];
      }
  
      ConstIterator begin() const { return characters(); }
      ConstIterator end() const { return begin() + length(); }
  
      bool starts_with(const StringView&, CaseSensitivity = CaseSensitivity::CaseSensitive) const;
      bool ends_with(const StringView&, CaseSensitivity = CaseSensitivity::CaseSensitive) const;
      bool starts_with(char) const;
      bool ends_with(char) const;
  
      bool operator==(const String&) const;
      bool operator!=(const String& other) const { return !(*this == other); }
  
      bool operator==(const StringView&) const;
      bool operator!=(const StringView& other) const { return !(*this == other); }
  
      bool operator==(const FlyString&) const;
      bool operator!=(const FlyString& other) const { return !(*this == other); }
  
      bool operator<(const String&) const;
      bool operator<(const char*) const;
      bool operator>=(const String& other) const { return !(*this < other); }
      bool operator>=(const char* other) const { return !(*this < other); }
  
      bool operator>(const String&) const;
      bool operator>(const char*) const;
      bool operator<=(const String& other) const { return !(*this > other); }
      bool operator<=(const char* other) const { return !(*this > other); }
  
      bool operator==(const char* cstring) const;
      bool operator!=(const char* cstring) const { return !(*this == cstring); }
  
      String isolated_copy() const;
  
      static String empty();
  
      StringImpl* impl() { return m_impl.ptr(); }
      const StringImpl* impl() const { return m_impl.ptr(); }
  
      String& operator=(String&& other)
      {
          if (this != &other)
              m_impl = move(other.m_impl);
          return *this;
      }
  
      String& operator=(const String& other)
      {
          if (this != &other)
              m_impl = const_cast<String&>(other).m_impl;
          return *this;
      }
  
      String& operator=(std::nullptr_t)
      {
          m_impl = nullptr;
          return *this;
      }
  
      String& operator=(ReadonlyBytes bytes)
      {
          m_impl = StringImpl::create(bytes);
          return *this;
      }
  
      u32 hash() const
      {
          if (!m_impl)
              return 0;
          return m_impl->hash();
      }
  
      ByteBuffer to_byte_buffer() const;
  
      template<typename BufferType>
      static String copy(const BufferType& buffer, ShouldChomp should_chomp = NoChomp)
      {
          if (buffer.is_null())
              return {};
          if (buffer.is_empty())
              return empty();
          return String((const char*)buffer.data(), buffer.size(), should_chomp);
      }
  
      static String format(const char*, ...);
      static String number(unsigned);
      static String number(unsigned long);
      static String number(unsigned long long);
      static String number(int);
      static String number(long);
      static String number(long long);
  
      StringView view() const;
  
      int replace(const String& needle, const String& replacement, bool all_occurences = false);
  
      template<typename T, typename... Rest>
      bool is_one_of(const T& string, Rest... rest) const
      {
          if (*this == string)
              return true;
          return is_one_of(rest...);
      }
  
  private:
      bool is_one_of() const { return false; }
  
      RefPtr<StringImpl> m_impl;
  };
  
  template<>
  struct Traits<String> : public GenericTraits<String> {
      static unsigned hash(const String& s) { return s.impl() ? s.impl()->hash() : 0; }
  };
  
  struct CaseInsensitiveStringTraits : public AK::Traits<String> {
      static unsigned hash(const String& s) { return s.impl() ? s.to_lowercase().impl()->hash() : 0; }
      static bool equals(const String& a, const String& b) { return a.to_lowercase() == b.to_lowercase(); }
  };
  
  bool operator<(const char*, const String&);
  bool operator>=(const char*, const String&);
  bool operator>(const char*, const String&);
  bool operator<=(const char*, const String&);
  
  String escape_html_entities(const StringView& html);
  
  inline InputMemoryStream& operator>>(InputMemoryStream& stream, String& string)
  {
      // FIXME: There was some talking about a generic lexer class?
  
      const auto start = stream.offset();
  
      while (!stream.eof() && stream.m_bytes[stream.m_offset]) {
          ++stream.m_offset;
      }
  
      if (stream.eof()) {
          stream.m_error = true;
          stream.m_offset = start;
          string = nullptr;
      } else {
          string = String { stream.bytes().slice(start, stream.offset() - start) };
          ++stream.m_offset;
      }
  
      return stream;
  }
  
  }
  
  using AK::CaseInsensitiveStringTraits;
  using AK::escape_html_entities;
  using AK::String;
  