зеркало из https://github.com/mozilla/gecko-dev.git
973 строки
28 KiB
C++
973 строки
28 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/*
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* The contents of this file are subject to the Netscape Public
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* License Version 1.1 (the "License"); you may not use this file
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* except in compliance with the License. You may obtain a copy of
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* the License at http://www.mozilla.org/NPL/
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*
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* Software distributed under the License is distributed on an "AS
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* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
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* implied. See the License for the specific language governing
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* rights and limitations under the License.
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*
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* The Original Code is mozilla.org code.
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*
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* The Initial Developer of the Original Code is Netscape
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* Communications Corporation. Portions created by Netscape are
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* Copyright (C) 1998 Netscape Communications Corporation. All
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* Rights Reserved.
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*
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* Contributor(s):
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* Scott Collins <scc@netscape.com>
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*/
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#ifndef _nsAReadableString_h__
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#define _nsAReadableString_h__
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// WORK IN PROGRESS
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#include "nscore.h"
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// for |PRUnichar|
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#include <string>
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// for |char_traits|
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#include <iterator>
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// for |bidirectional_iterator_tag|
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/*
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This file defines the abstract interfaces |nsAReadableString| and
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|nsAReadableCString| (the 'A' is for 'abstract', as opposed to the 'I' in
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[XP]COM interface names).
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These types are intended to be as source compatible as possible with the original
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definitions of |const nsString&| and |const nsCString&|, respectively. In otherwords,
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these interfaces provide only non-mutating access to the underlying strings. We
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split the these interfaces out from the mutating parts (see
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"nsAWritableString.h") because tests showed that we could exploit specialized
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implementations in some areas; we need an abstract interface to bring the whole
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family of strings together.
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|nsAReadableString| is a string of |PRUnichar|s. |nsAReadableCString| (note the
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'C') is a string of |char|s.
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*/
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template <class CharT> class basic_nsAWritableString;
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// ...because we sometimes use them as `out' params
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template <class CharT> class basic_nsLiteralString;
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// ...because we sometimes use them as in params to force the conversion of |CharT*|s
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//
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// nsAReadable[C]String
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//
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template <class CharT>
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class basic_nsAReadableString
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/*
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...
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*/
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{
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protected:
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struct ConstFragment
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{
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const CharT* mStart;
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const CharT* mEnd;
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PRUint32 mFragmentIdentifier;
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ConstFragment()
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: mStart(0), mEnd(0), mFragmentIdentifier(0)
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{
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// nothing else to do here
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}
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};
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public:
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enum FragmentRequest { kPrevFragment, kFirstFragment, kLastFragment, kNextFragment, kFragmentAt };
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// Damn! Had to make |GetConstFragment| public because the compilers suck. Should be protected.
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virtual const CharT* GetConstFragment( ConstFragment&, FragmentRequest, PRUint32 = 0 ) const = 0;
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friend class ConstIterator;
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class ConstIterator
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: public std::bidirectional_iterator_tag
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{
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public:
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typedef ptrdiff_t difference_type;
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typedef CharT value_type;
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typedef const CharT* pointer;
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typedef const CharT& reference;
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typedef bidirectional_iterator_tag iterator_category;
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private:
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friend class basic_nsAReadableString<CharT>;
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ConstFragment mFragment;
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const CharT* mPosition;
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const basic_nsAReadableString<CharT>* mOwningString;
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void
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normalize_forward()
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{
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if ( mPosition == mFragment.mEnd )
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if ( mOwningString->GetConstFragment(mFragment, kNextFragment) )
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mPosition = mFragment.mStart;
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}
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void
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normalize_backward()
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{
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if ( mPosition == mFragment.mStart )
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if ( mOwningString->GetConstFragment(mFragment, kPrevFragment) )
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mPosition = mFragment.mEnd;
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}
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ConstIterator( const ConstFragment& aFragment,
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const CharT* aStartingPosition,
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const basic_nsAReadableString<CharT>& aOwningString )
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: mFragment(aFragment),
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mPosition(aStartingPosition),
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mOwningString(&aOwningString)
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{
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// nothing else to do here
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}
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public:
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// ConstIterator( const ConstIterator& ); ...use default copy-constructor
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// ConstIterator& operator=( const ConstIterator& ); ...use default copy-assignment operator
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CharT
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operator*()
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{
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return *mPosition;
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}
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ConstIterator&
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operator++()
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{
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++mPosition;
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normalize_forward();
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return *this;
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}
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ConstIterator
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operator++( int )
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{
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ConstIterator result(*this);
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++mPosition;
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normalize_forward();
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return result;
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}
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ConstIterator&
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operator--()
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{
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normalize_backward();
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--mPosition;
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return *this;
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}
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ConstIterator
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operator--( int )
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{
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ConstIterator result(*this);
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normalize_backward();
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--mPosition;
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return result;
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}
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// Damn again! Problems with templates made me implement comparisons as members.
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PRBool
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operator==( const ConstIterator& rhs )
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{
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return mPosition == rhs.mPosition;
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}
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PRBool
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operator!=( const ConstIterator& rhs )
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{
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return mPosition != rhs.mPosition;
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}
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};
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public:
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ConstIterator
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Begin( PRUint32 aOffset = 0 ) const
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{
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ConstFragment fragment;
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const CharT* startPos = GetConstFragment(fragment, kFragmentAt, aOffset);
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return ConstIterator(fragment, startPos, *this);
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}
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ConstIterator
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End( PRUint32 aOffset = 0 ) const
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{
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ConstFragment fragment;
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const CharT* startPos = GetConstFragment(fragment, kFragmentAt, max(0U, Length()-aOffset));
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return ConstIterator(fragment, startPos, *this);
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}
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public:
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virtual ~basic_nsAReadableString<CharT>() { }
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// ...yes, I expect to be sub-classed.
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virtual PRUint32 Length() const = 0;
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PRBool
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IsEmpty() const
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{
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return Length() == 0;
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}
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/*
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RickG says the following three routines, |IsUnicode()|, |GetBuffer()|, and |GetUnicode()|
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shouldn't be implemented because they're wrong access. I agree. Callers who really need
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this access should use the iterators instead. We'll use these to ease the transition to
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|nsAReadable...|, and then remove them as soon as possible.
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*/
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PRBool IsUnicode() const { return PR_FALSE; }
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// ...but note specialization for |PRUnichar|, below
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const char* GetBuffer() const { return 0; }
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const PRUnichar* GetUnicode() const { return 0; }
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// ...but note specializations for |char| and |PRUnichar|, below
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CharT CharAt( PRUint32 ) const;
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CharT operator[]( PRUint32 ) const;
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CharT First() const;
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CharT Last() const;
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PRUint32 CountChar( CharT ) const;
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PRUint32 Left( basic_nsAWritableString<CharT>&, PRUint32 ) const;
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PRUint32 Mid( basic_nsAWritableString<CharT>&, PRUint32, PRUint32 ) const;
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PRUint32 Right( basic_nsAWritableString<CharT>&, PRUint32 ) const;
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// Find( ... ) const;
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// FindChar( ... ) const;
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// FindCharInSet( ... ) const;
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// RFind( ... ) const;
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// RFindChar( ... ) const;
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// RFindCharInSet( ... ) const;
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int Compare( const basic_nsAReadableString<CharT>& rhs ) const;
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int Compare( const basic_nsLiteralString<CharT>& rhs ) const;
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// |Equals()| is a synonym for |Compare()|
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PRBool
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Equals( const basic_nsAReadableString<CharT>& rhs ) const
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{
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return Compare(rhs) == 0;
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}
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PRBool
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Equals( const basic_nsLiteralString<CharT>& rhs ) const
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{
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return Compare(rhs) == 0;
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}
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/*
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Shouldn't be implemented because they're i18n sensitive.
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Let's leave them in |nsString| for now.
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*/
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// ToLowerCase
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// ToUpperCase
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// EqualsIgnoreCase
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// IsASCII
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// IsSpace
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// IsAlpha
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// IsDigit
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// ToFloat
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// ToInteger
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// char* ToNewCString() const;
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// char* ToNewUTF8String() const;
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// PRUnichar* ToNewUnicode() const;
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// char* ToCString( char*, PRUint32, PRUint32 ) const;
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/*
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Shouldn't be implemented because it's wrong duplication.
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Let's leave it in |nsString| for now.
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*/
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// nsString* ToNewString() const;
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// NO! The right way to say this is |new nsString( fromAReadableString )|
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/*
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Shouldn't be implemented because they're not generally applicable.
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Let's leave them in |nsString| for now.
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*/
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// IsOrdered
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// BinarySearch
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// Comparison operators are all synonyms for |Compare()|
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PRBool operator!=( const basic_nsAReadableString<CharT>& rhs ) const { return Compare(rhs)!=0; }
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PRBool operator< ( const basic_nsAReadableString<CharT>& rhs ) const { return Compare(rhs)< 0; }
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PRBool operator<=( const basic_nsAReadableString<CharT>& rhs ) const { return Compare(rhs)<=0; }
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PRBool operator==( const basic_nsAReadableString<CharT>& rhs ) const { return Compare(rhs)==0; }
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PRBool operator>=( const basic_nsAReadableString<CharT>& rhs ) const { return Compare(rhs)>=0; }
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PRBool operator> ( const basic_nsAReadableString<CharT>& rhs ) const { return Compare(rhs)> 0; }
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};
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#define NS_DEF_1_STRING_COMPARISON_OPERATOR(comp, T1, T2) \
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template <class CharT> \
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inline \
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PRBool \
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operator comp( T1 lhs, T2 rhs ) \
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{ \
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return PRBool(Compare(lhs, rhs) comp 0); \
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}
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#define NS_DEF_STRING_COMPARISON_OPERATORS(T1, T2) \
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NS_DEF_1_STRING_COMPARISON_OPERATOR(!=, T1, T2) \
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NS_DEF_1_STRING_COMPARISON_OPERATOR(< , T1, T2) \
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NS_DEF_1_STRING_COMPARISON_OPERATOR(<=, T1, T2) \
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NS_DEF_1_STRING_COMPARISON_OPERATOR(==, T1, T2) \
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NS_DEF_1_STRING_COMPARISON_OPERATOR(>=, T1, T2) \
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NS_DEF_1_STRING_COMPARISON_OPERATOR(> , T1, T2)
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#define NS_DEF_STRING_COMPARISONS(T) \
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NS_DEF_STRING_COMPARISON_OPERATORS(const T&, const CharT*) \
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NS_DEF_STRING_COMPARISON_OPERATORS(const CharT*, const T&)
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NS_DEF_STRING_COMPARISONS(basic_nsAReadableString<CharT>)
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NS_SPECIALIZE_TEMPLATE
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inline
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PRBool
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basic_nsAReadableString<PRUnichar>::IsUnicode() const
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{
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return PR_TRUE;
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}
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NS_SPECIALIZE_TEMPLATE
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inline
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const char*
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basic_nsAReadableString<char>::GetBuffer() const
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// DEPRECATED: use the iterators instead
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{
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ConstFragment fragment;
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GetConstFragment(fragment, kFirstFragment);
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return fragment.mStart;
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}
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NS_SPECIALIZE_TEMPLATE
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inline
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const PRUnichar*
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basic_nsAReadableString<PRUnichar>::GetUnicode() const
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// DEPRECATED: use the iterators instead
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{
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ConstFragment fragment;
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GetConstFragment(fragment, kFirstFragment);
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return fragment.mStart;
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}
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/*
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Note: the following four functions, |CharAt|, |operator[]|, |First|, and |Last|, are implemented
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in the simplest reasonable scheme; by calling |GetConstFragment| and resolving the pointer it
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returns. The alternative is to force at least one of these methods to be |virtual|. The ideal
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candidate for that change would be |CharAt|.
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This is something to measure in the context of how string classes are actually used. In practice,
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do people extract a character at a time in performance critical places? If so, can they use
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iterators instead? If they must extract single characters, _and_ they can't use iterators, _and_
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it happens enough to notice, then we'll take the hit and make |CharAt| virtual.
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*/
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template <class CharT>
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inline
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CharT
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basic_nsAReadableString<CharT>::CharAt( PRUint32 aIndex ) const
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{
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// ??? Is |CharAt()| supposed to be the 'safe' version?
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ConstFragment fragment;
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return *GetConstFragment(fragment, kFragmentAt, aIndex);
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}
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template <class CharT>
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inline
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CharT
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basic_nsAReadableString<CharT>::operator[]( PRUint32 aIndex ) const
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{
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return CharAt(aIndex);
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}
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template <class CharT>
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inline
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CharT
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basic_nsAReadableString<CharT>::First() const
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{
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return CharAt(0);
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}
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template <class CharT>
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inline
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CharT
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basic_nsAReadableString<CharT>::Last() const
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{
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return CharAt(Length()-1);
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}
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template <class CharT>
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PRUint32
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basic_nsAReadableString<CharT>::CountChar( CharT c ) const
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{
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return count(Begin(), End(), c);
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}
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/*
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Note: |Left()|, |Mid()|, and |Right()| could be modified to notice when they degenerate into copying the
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entire string, and call |Assign()| instead. This would be a win when the underlying implementation of
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both strings could do buffer sharing. This is _definitely_ something that should be measured before
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being implemented.
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*/
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template <class CharT>
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PRUint32
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basic_nsAReadableString<CharT>::Left( basic_nsAWritableString<CharT>& aResult, PRUint32 aLengthToCopy ) const
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{
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aResult = Substring(*this, 0, aLengthToCopy);
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return aResult.Length();
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}
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template <class CharT>
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PRUint32
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basic_nsAReadableString<CharT>::Mid( basic_nsAWritableString<CharT>& aResult, PRUint32 aStartPos, PRUint32 aLengthToCopy ) const
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{
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aResult = Substring(*this, aStartPos, aLengthToCopy);
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return aResult.Length();
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}
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template <class CharT>
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PRUint32
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basic_nsAReadableString<CharT>::Right( basic_nsAWritableString<CharT>& aResult, PRUint32 aLengthToCopy ) const
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{
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PRUint32 myLength = Length();
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aLengthToCopy = min(myLength, aLengthToCopy);
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aResult = Substring(*this, myLength-aLengthToCopy, aLengthToCopy);
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return aResult.Length();
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}
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template <class CharT>
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inline
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int
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basic_nsAReadableString<CharT>::Compare( const basic_nsAReadableString<CharT>& rhs ) const
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{
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return ::Compare(*this, rhs);
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}
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template <class CharT>
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inline
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int
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basic_nsAReadableString<CharT>::Compare( const basic_nsLiteralString<CharT>& rhs ) const
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{
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return ::Compare(*this, rhs);
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}
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//
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// nsLiteral[C]String
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//
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template <class CharT>
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class basic_nsLiteralString
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: public basic_nsAReadableString<CharT>
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/*
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...this class wraps a constant literal string and lets it act like an |nsAReadable...|.
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Use it like this:
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SomeFunctionTakingACString( nsLiteralCString("Hello, World!") );
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With some tweaking, I think I can make this work as well...
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SomeStringFunc( nsLiteralString( L"Hello, World!" ) );
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This class just holds a pointer. If you don't supply the length, it must calculate it.
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No copying or allocations are performed.
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|const basic_nsLiteralString<CharT>&| appears frequently in interfaces because it
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allows the automatic conversion of a |CharT*|.
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*/
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{
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typedef typename basic_nsAReadableString<CharT>::FragmentRequest FragmentRequest;
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typedef typename basic_nsAWritableString<CharT>::ConstFragment ConstFragment;
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protected:
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virtual const CharT* GetConstFragment( ConstFragment&, FragmentRequest, PRUint32 ) const;
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public:
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// Note: _not_ explicit
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basic_nsLiteralString( const CharT* aLiteral )
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: mStart(aLiteral),
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mEnd(mStart + char_traits<CharT>::length(mStart))
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{
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// nothing else to do here
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}
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basic_nsLiteralString( const CharT* aLiteral, PRUint32 aLength )
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: mStart(aLiteral)
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mEnd(mStart + aLength)
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{
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// nothing else to do here
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}
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virtual PRUint32 Length() const;
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private:
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const CharT* mStart;
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const CharT* mEnd;
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};
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NS_DEF_STRING_COMPARISONS(basic_nsLiteralString<CharT>)
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template <class CharT>
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const CharT*
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basic_nsLiteralString<CharT>::GetConstFragment( ConstFragment& aFragment, FragmentRequest aRequest, PRUint32 aOffset ) const
|
|
{
|
|
switch ( aRequest )
|
|
{
|
|
case kFirstFragment:
|
|
case kLastFragment:
|
|
case kFragmentAt:
|
|
aFragment.mStart = mStart;
|
|
aFragment.mEnd = mEnd;
|
|
return mStart + aOffset;
|
|
|
|
case kPrevFragment:
|
|
case kNextFragment:
|
|
default:
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
template <class CharT>
|
|
PRUint32
|
|
basic_nsLiteralString<CharT>::Length() const
|
|
{
|
|
return PRUint32(mEnd - mStart);
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
//
|
|
// nsPromiseConcatenation
|
|
//
|
|
|
|
template <class CharT>
|
|
class nsPromiseConcatenation
|
|
: public basic_nsAReadableString<CharT>
|
|
/*
|
|
NOT FOR USE BY HUMANS
|
|
|
|
Instances of this class only exist as anonymous temporary results from |operator+()|.
|
|
This is the machinery that makes string concatenation efficient. No allocations or
|
|
character copies are required unless and until a final assignment is made. It works
|
|
its magic by overriding and forwarding calls to |GetConstFragment()|.
|
|
|
|
Note: |nsPromiseConcatenation| imposes some limits on string concatenation with |operator+()|.
|
|
- no more than 33 strings, e.g., |s1 + s2 + s3 + ... s32 + s33|
|
|
- left to right evaluation is required ... do not use parentheses to override this
|
|
|
|
In practice, neither of these is onerous. Parentheses do not change the semantics of the
|
|
concatenation, only the order in which the result is assembled ... so there's no reason
|
|
for a user to need to control it. Too many strings summed together can easily be worked
|
|
around with an intermediate assignment. I wouldn't have the parentheses limitation if I
|
|
assigned the identifier mask starting at the top, the first time anybody called
|
|
|GetConstFragment()|.
|
|
*/
|
|
{
|
|
typedef typename basic_nsAReadableString<CharT>::FragmentRequest FragmentRequest;
|
|
typedef typename basic_nsAWritableString<CharT>::ConstFragment ConstFragment;
|
|
|
|
protected:
|
|
virtual const CharT* GetConstFragment( ConstFragment&, FragmentRequest, PRUint32 ) const;
|
|
|
|
static const int kLeftString = 0;
|
|
static const int kRightString = 1;
|
|
|
|
int
|
|
GetCurrentStringFromFragment( const ConstFragment& aFragment ) const
|
|
{
|
|
return (aFragment.mFragmentIdentifier & mFragmentIdentifierMask) ? kRightString : kLeftString;
|
|
}
|
|
|
|
int
|
|
SetLeftStringInFragment( ConstFragment& aFragment ) const
|
|
{
|
|
aFragment.mFragmentIdentifier &= ~mFragmentIdentifierMask;
|
|
return kLeftString;
|
|
}
|
|
|
|
int
|
|
SetRightStringInFragment( ConstFragment& aFragment ) const
|
|
{
|
|
aFragment.mFragmentIdentifier |= mFragmentIdentifierMask;
|
|
return kRightString;
|
|
}
|
|
|
|
public:
|
|
nsPromiseConcatenation( const basic_nsAReadableString<CharT>& aLeftString, const basic_nsAReadableString<CharT>& aRightString, PRUint32 aMask = 1 )
|
|
: mFragmentIdentifierMask(aMask)
|
|
{
|
|
mStrings[kLeftString] = &aLeftString;
|
|
mStrings[kRightString] = &aRightString;
|
|
}
|
|
|
|
virtual PRUint32 Length() const;
|
|
|
|
nsPromiseConcatenation<CharT> operator+( const basic_nsAReadableString<CharT>& rhs ) const;
|
|
|
|
private:
|
|
void operator+( const nsPromiseConcatenation<CharT>& ); // NOT TO BE IMPLEMENTED
|
|
// making this |private| stops you from over parenthesizing concatenation expressions, e.g., |(A+B) + (C+D)|
|
|
// which would break the algorithm for distributing bits in the fragment identifier
|
|
|
|
private:
|
|
const basic_nsAReadableString<CharT>* mStrings[2];
|
|
PRUint32 mFragmentIdentifierMask;
|
|
};
|
|
|
|
NS_DEF_STRING_COMPARISONS(nsPromiseConcatenation<CharT>)
|
|
|
|
template <class CharT>
|
|
PRUint32
|
|
nsPromiseConcatenation<CharT>::Length() const
|
|
{
|
|
return mStrings[kLeftString]->Length() + mStrings[kRightString]->Length();
|
|
}
|
|
|
|
template <class CharT>
|
|
const CharT*
|
|
nsPromiseConcatenation<CharT>::GetConstFragment( ConstFragment& aFragment, FragmentRequest aRequest, PRUint32 aPosition ) const
|
|
{
|
|
const int kLeftString = 0;
|
|
const int kRightString = 1;
|
|
|
|
int whichString;
|
|
|
|
// based on the request, pick which string we will forward the |GetConstFragment()| call into
|
|
|
|
switch ( aRequest )
|
|
{
|
|
case kPrevFragment:
|
|
case kNextFragment:
|
|
whichString = GetCurrentStringFromFragment(aFragment);
|
|
break;
|
|
|
|
case kFirstFragment:
|
|
whichString = SetLeftStringInFragment(aFragment);
|
|
break;
|
|
|
|
case kLastFragment:
|
|
whichString = SetRightStringInFragment(aFragment);
|
|
break;
|
|
|
|
case kFragmentAt:
|
|
PRUint32 leftLength = mStrings[kLeftString]->Length();
|
|
if ( aPosition < leftLength )
|
|
whichString = SetLeftStringInFragment(aFragment);
|
|
else
|
|
{
|
|
whichString = SetRightStringInFragment(aFragment);
|
|
aPosition -= leftLength;
|
|
}
|
|
break;
|
|
|
|
}
|
|
|
|
const CharT* result;
|
|
bool done;
|
|
do
|
|
{
|
|
done = true;
|
|
result = mStrings[whichString]->GetConstFragment(aFragment, aRequest, aPosition);
|
|
|
|
if ( !result )
|
|
{
|
|
done = false;
|
|
if ( aRequest == kNextFragment && whichString == kLeftString )
|
|
{
|
|
aRequest = kFirstFragment;
|
|
whichString = SetRightStringInFragment(aFragment);
|
|
}
|
|
else if ( aRequest == kPrevFragment && whichString == kRightString )
|
|
{
|
|
aRequest = kLastFragment;
|
|
whichString = SetLeftStringInFragment(aFragment);
|
|
}
|
|
else
|
|
done = true;
|
|
}
|
|
}
|
|
while ( !done );
|
|
return result;
|
|
}
|
|
|
|
template <class CharT>
|
|
nsPromiseConcatenation<CharT>
|
|
nsPromiseConcatenation<CharT>::operator+( const basic_nsAReadableString<CharT>& rhs ) const
|
|
{
|
|
return nsPromiseConcatenation<CharT>(*this, rhs, mFragmentIdentifierMask<<1);
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
//
|
|
// nsPromiseSubstring
|
|
//
|
|
|
|
template <class CharT>
|
|
class nsPromiseSubstring
|
|
: public basic_nsAReadableString<CharT>
|
|
/*
|
|
NOT FOR USE BY HUMANS (mostly)
|
|
|
|
...not unlike |nsPromiseConcatenation|. Instances of this class exist only as anonymous
|
|
temporary results from |Substring()|. Like |nsPromiseConcatenation|, this class only
|
|
holds a pointer, no string data of its own. It does its magic by overriding and forwarding
|
|
calls to |GetConstFragment()|.
|
|
*/
|
|
{
|
|
typedef typename basic_nsAReadableString<CharT>::FragmentRequest FragmentRequest;
|
|
typedef typename basic_nsAWritableString<CharT>::ConstFragment ConstFragment;
|
|
|
|
protected:
|
|
virtual const CharT* GetConstFragment( ConstFragment&, FragmentRequest, PRUint32 ) const;
|
|
|
|
public:
|
|
nsPromiseSubstring( const basic_nsAReadableString<CharT>& aString, PRUint32 aStartPos, PRUint32 aLength )
|
|
: mString(aString),
|
|
mStartPos( min(aStartPos, aString.Length()) ),
|
|
mLength( min(aLength, aString.Length()-mStartPos) )
|
|
{
|
|
// nothing else to do here
|
|
}
|
|
|
|
virtual PRUint32 Length() const;
|
|
|
|
private:
|
|
const basic_nsAReadableString<CharT>& mString;
|
|
PRUint32 mStartPos;
|
|
PRUint32 mLength;
|
|
};
|
|
|
|
NS_DEF_STRING_COMPARISONS(nsPromiseSubstring<CharT>)
|
|
|
|
template <class CharT>
|
|
PRUint32
|
|
nsPromiseSubstring<CharT>::Length() const
|
|
{
|
|
return mLength;
|
|
}
|
|
|
|
template <class CharT>
|
|
const CharT*
|
|
nsPromiseSubstring<CharT>::GetConstFragment( ConstFragment& aFragment, FragmentRequest aRequest, PRUint32 aPosition ) const
|
|
{
|
|
// Offset any request for a specific position (First, Last, At) by our
|
|
// substrings startpos within the owning string
|
|
|
|
if ( aRequest == kFirstFragment )
|
|
{
|
|
aPosition = mStartPos;
|
|
aRequest = kFragmentAt;
|
|
}
|
|
else if ( aRequest == kLastFragment )
|
|
{
|
|
aPosition = mStartPos + mLength;
|
|
aRequest = kFragmentAt;
|
|
}
|
|
else if ( aRequest == kFragmentAt )
|
|
aPosition += mStartPos;
|
|
|
|
return mString.GetConstFragment(aFragment, aRequest, aPosition);
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
//
|
|
// Global functions
|
|
//
|
|
|
|
template <class CharT>
|
|
nsPromiseSubstring<CharT>
|
|
Substring( const basic_nsAReadableString<CharT>& aString, PRUint32 aStartPos, PRUint32 aSubstringLength )
|
|
{
|
|
return nsPromiseSubstring<CharT>(aString, aStartPos, aSubstringLength);
|
|
}
|
|
|
|
|
|
template <class CharT>
|
|
int
|
|
Compare( const basic_nsAReadableString<CharT>& lhs, const basic_nsAReadableString<CharT>& rhs )
|
|
{
|
|
/*
|
|
If this turns out to be too slow (after measurement), there are two important modifications
|
|
1) chunky iterators
|
|
2) and then possibly use |char_traits<T>::compare|
|
|
*/
|
|
|
|
PRUint32 lLength = lhs.Length();
|
|
PRUint32 rLength = rhs.Length();
|
|
PRUint32 lengthToCompare = min(lLength, rLength);
|
|
|
|
typedef typename basic_nsAReadableString<CharT>::ConstIterator ConstIterator;
|
|
ConstIterator lPos = lhs.Begin();
|
|
ConstIterator lEnd = lhs.Begin(lengthToCompare);
|
|
ConstIterator rPos = rhs.Begin();
|
|
|
|
while ( lPos != lEnd )
|
|
{
|
|
if ( *lPos < *rPos )
|
|
return -1;
|
|
if ( *rPos < *lPos )
|
|
return 1;
|
|
|
|
++lPos;
|
|
++rPos;
|
|
}
|
|
|
|
if ( lLength < rLength )
|
|
return -1;
|
|
else if ( rLength < lLength )
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
template <class CharT>
|
|
inline
|
|
int
|
|
Compare( const basic_nsAReadableString<CharT>& lhs, const CharT* rhs )
|
|
{
|
|
return Compare(lhs, basic_nsLiteralString<CharT>(rhs));
|
|
}
|
|
|
|
template <class CharT>
|
|
inline
|
|
int
|
|
Compare( const CharT* lhs, const basic_nsAReadableString<CharT>& rhs )
|
|
{
|
|
return Compare(basic_nsLiteralString<CharT>(lhs), rhs);
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
How shall we provide |operator+()|?
|
|
|
|
What would it return? It has to return a stack based object, because the client will
|
|
not be given an opportunity to handle memory management in an expression like
|
|
|
|
myWritableString = stringA + stringB + stringC;
|
|
|
|
...so the `obvious' answer of returning a new |nsSharedString| is no good. We could
|
|
return an |nsString|, if that name were in scope here, though there's no telling what the client
|
|
will really want to do with the result. What might be better, though,
|
|
is to return a `promise' to concatenate some strings...
|
|
|
|
By making |nsPromiseConcatenation| inherit from readable strings, we automatically handle
|
|
assignment and other interesting uses within writable strings, plus we drastically reduce
|
|
the number of cases we have to write |operator+()| for. The cost is extra temporary concat strings
|
|
in the evaluation of strings of '+'s, e.g., |A + B + C + D|, and that we have to do some work
|
|
to implement the virtual functions of readables.
|
|
*/
|
|
|
|
template <class CharT>
|
|
nsPromiseConcatenation<CharT>
|
|
operator+( const basic_nsAReadableString<CharT>& lhs, const basic_nsAReadableString<CharT>& rhs )
|
|
{
|
|
return nsPromiseConcatenation<CharT>(lhs, rhs);
|
|
}
|
|
|
|
template <class CharT>
|
|
nsPromiseConcatenation<CharT>
|
|
operator+( const basic_nsAReadableString<CharT>& lhs, const basic_nsLiteralString<CharT>& rhs )
|
|
{
|
|
return nsPromiseConcatenation<CharT>(lhs, rhs);
|
|
}
|
|
|
|
template <class CharT>
|
|
nsPromiseConcatenation<CharT>
|
|
operator+( const basic_nsLiteralString<CharT>& lhs, const basic_nsAReadableString<CharT>& rhs )
|
|
{
|
|
return nsPromiseConcatenation<CharT>(lhs, rhs);
|
|
}
|
|
|
|
template <class CharT>
|
|
nsPromiseConcatenation<CharT>
|
|
operator+( const basic_nsLiteralString<CharT>& lhs, const basic_nsLiteralString<CharT>& rhs )
|
|
{
|
|
return nsPromiseConcatenation<CharT>(lhs, rhs);
|
|
}
|
|
|
|
|
|
|
|
|
|
template <class CharT, class TraitsT>
|
|
basic_ostream<CharT, class TraitsT>&
|
|
operator<<( basic_ostream<CharT, TraitsT>& os, const basic_nsAReadableString<CharT>& s )
|
|
{
|
|
std::copy(s.Begin(), s.End(), ostream_iterator<CharT, CharT, TraitsT>(os));
|
|
return os;
|
|
}
|
|
|
|
typedef basic_nsAReadableString<PRUnichar> nsAReadableString;
|
|
typedef basic_nsAReadableString<char> nsAReadableCString;
|
|
|
|
typedef basic_nsLiteralString<PRUnichar> nsLiteralString;
|
|
typedef basic_nsLiteralString<char> nsLiteralCString;
|
|
|
|
#endif // !defined(_nsAReadableString_h__)
|