/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* vim: set ts=8 sts=2 et sw=2 tw=80: */ /* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #ifndef nsStringIterator_h___ #define nsStringIterator_h___ #include "nsCharTraits.h" #include "nsAlgorithm.h" #include "nsDebug.h" /** * @see nsTAString */ template <class CharT> class nsReadingIterator { public: typedef nsReadingIterator<CharT> self_type; typedef ptrdiff_t difference_type; typedef size_t size_type; typedef CharT value_type; typedef const CharT* pointer; typedef const CharT& reference; private: friend class mozilla::detail::nsTStringRepr<CharT>; // unfortunately, the API for nsReadingIterator requires that the // iterator know its start and end positions. this was needed when // we supported multi-fragment strings, but now it is really just // extra baggage. we should remove mStart and mEnd at some point. const CharT* mStart; const CharT* mEnd; const CharT* mPosition; public: nsReadingIterator() : mStart(nullptr), mEnd(nullptr), mPosition(nullptr) {} // clang-format off // nsReadingIterator( const nsReadingIterator<CharT>& ); // auto-generated copy-constructor OK // nsReadingIterator<CharT>& operator=( const nsReadingIterator<CharT>& ); // auto-generated copy-assignment operator OK // clang-format on pointer get() const { return mPosition; } CharT operator*() const { return *get(); } self_type& operator++() { ++mPosition; return *this; } self_type operator++(int) { self_type result(*this); ++mPosition; return result; } self_type& operator--() { --mPosition; return *this; } self_type operator--(int) { self_type result(*this); --mPosition; return result; } self_type& advance(difference_type aN) { if (aN > 0) { difference_type step = XPCOM_MIN(aN, mEnd - mPosition); NS_ASSERTION( step > 0, "can't advance a reading iterator beyond the end of a string"); mPosition += step; } else if (aN < 0) { difference_type step = XPCOM_MAX(aN, -(mPosition - mStart)); NS_ASSERTION(step < 0, "can't advance (backward) a reading iterator beyond the end " "of a string"); mPosition += step; } return *this; } // We return an unsigned type here (with corresponding assert) rather than // the more usual difference_type because we want to make this class go // away in favor of mozilla::RangedPtr. Since RangedPtr has the same // requirement we are enforcing here, the transition ought to be much // smoother. size_type operator-(const self_type& aOther) const { MOZ_ASSERT(mPosition >= aOther.mPosition); return mPosition - aOther.mPosition; } }; template <class CharT> inline bool operator==(const nsReadingIterator<CharT>& aLhs, const nsReadingIterator<CharT>& aRhs) { return aLhs.get() == aRhs.get(); } template <class CharT> inline bool operator!=(const nsReadingIterator<CharT>& aLhs, const nsReadingIterator<CharT>& aRhs) { return aLhs.get() != aRhs.get(); } #endif /* !defined(nsStringIterator_h___) */