gecko-dev/string/public/nsAWritableString.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/*
* The contents of this file are subject to the Netscape Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/NPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is mozilla.org code.
*
* The Initial Developer of the Original Code is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
* Scott Collins <scc@netscape.com>
*/
#ifndef _nsAWritableString_h__
#define _nsAWritableString_h__
// WORK IN PROGRESS
// See also...
#include "nsAReadableString.h"
/*
This file defines the abstract interfaces |nsAWritableString| and
|nsAWritableCString|.
|nsAWritableString| is a string of |PRUnichar|s. |nsAWritableCString| (note the
'C') is a string of |char|s.
*/
template <class CharT>
class basic_nsAWritableString
: public basic_nsAReadableString<CharT>
/*
...
*/
{
protected:
typedef typename basic_nsAReadableString<CharT>::FragmentRequest FragmentRequest;
struct WritableFragment
{
CharT* mStart;
CharT* mEnd;
PRUint32 mFragmentIdentifier;
WritableFragment()
: mStart(0), mEnd(0), mFragmentIdentifier(0)
{
// nothing else to do here
}
};
public:
virtual CharT* GetWritableFragment( WritableFragment&, FragmentRequest, PRUint32 = 0 ) = 0;
friend class WritingIterator;
class WritingIterator
: public bidirectional_iterator_tag
{
public:
typedef ptrdiff_t difference_type;
typedef CharT value_type;
typedef CharT* pointer;
typedef CharT& reference;
typedef bidirectional_iterator_tag iterator_category;
private:
friend class basic_nsAWritableString<CharT>;
WritableFragment mFragment;
CharT* mPosition;
basic_nsAWritableString<CharT>* mOwningString;
void
normalize_forward()
{
if ( mPosition == mFragment.mEnd )
if ( mOwningString->GetWritableFragment(mFragment, kNextFragment) )
mPosition = mFragment.mStart;
}
void
normalize_backward()
{
if ( mPosition == mFragment.mStart )
if ( mOwningString->GetWritableFragment(mFragment, kPrevFragment) )
mPosition = mFragment.mEnd;
}
WritingIterator( WritableFragment& aFragment,
CharT* aStartingPosition,
basic_nsAWritableString<CharT>& aOwningString )
: mFragment(aFragment),
mPosition(aStartingPosition),
mOwningString(&aOwningString)
{
// nothing else to do here
}
public:
// WritingIterator( const WritingIterator& ); ...use default copy-constructor
// WritingIterator& operator=( const WritingIterator& ); ...use default copy-assignment operator
reference
operator*() const
{
return *mPosition;
}
pointer
operator->() const
{
return mPosition;
}
WritingIterator&
operator++()
{
++mPosition;
normalize_forward();
return *this;
}
WritingIterator
operator++( int )
{
WritingIterator result(*this);
++mPosition;
normalize_forward();
return result;
}
WritingIterator&
operator--()
{
normalize_backward();
--mPosition;
return *this;
}
WritingIterator
operator--( int )
{
WritingIterator result(*this);
normalize_backward();
--mPosition;
return result;
}
const WritableFragment&
fragment() const
{
return mFragment;
}
difference_type
size_forward() const
{
return mFragment.mEnd - mPosition;
}
difference_type
size_backward() const
{
return mPosition - mFragment.mStart;
}
WritingIterator&
operator+=( difference_type n )
{
if ( n < 0 )
return operator-=(-n);
while ( n )
{
difference_type one_hop = NS_MIN(n, size_forward());
mPosition += one_hop;
normalize_forward();
n -= one_hop;
}
return *this;
}
WritingIterator&
operator-=( difference_type n )
{
if ( n < 0 )
return operator+=(-n);
while ( n )
{
difference_type one_hop = NS_MIN(n, size_backward());
mPosition -= one_hop;
normalize_backward();
n -= one_hop;
}
return *this;
}
PRBool
operator==( const WritingIterator& rhs ) const
{
return mPosition == rhs.mPosition;
}
PRBool
operator!=( const WritingIterator& rhs ) const
{
return mPosition != rhs.mPosition;
}
};
typedef WritingIterator Iterator;
public:
basic_nsAWritableString<CharT>::WritingIterator
BeginWriting( PRUint32 aOffset = 0 )
{
WritableFragment fragment;
CharT* startPos = GetWritableFragment(fragment, kFragmentAt, aOffset);
return basic_nsAWritableString<CharT>::WritingIterator(fragment, startPos, *this);
}
basic_nsAWritableString<CharT>::WritingIterator
EndWriting( PRUint32 aOffset = 0 )
{
WritableFragment fragment;
CharT* startPos = GetWritableFragment(fragment, kFragmentAt, NS_MAX(0U, Length()-aOffset));
return basic_nsAWritableString<CharT>::WritingIterator(fragment, startPos, *this);
}
virtual void SetCapacity( PRUint32 ) = 0;
virtual void SetLength( PRUint32 ) = 0;
void
Truncate( PRUint32 aNewLength=0 )
{
NS_ASSERTION(aNewLength<=Length(), "Can't use |Truncate()| to make a string longer.");
if ( aNewLength < Length() )
SetLength(aNewLength);
}
// PRBool SetCharAt( char_type, index_type ) = 0;
// void ToLowerCase();
// void ToUpperCase();
// void StripChars( const CharT* aSet );
// void StripChar( ... );
// void StripWhitespace();
// void ReplaceChar( ... );
// void ReplaceSubstring( ... );
// void Trim( ... );
// void CompressSet( ... );
// void CompressWhitespace( ... );
virtual void Assign( const basic_nsAReadableString<CharT>& rhs );
// virtual void AssignChar( CharT ) = 0;
virtual void Append( const basic_nsAReadableString<CharT>& );
virtual void AppendChar( CharT );
virtual void Insert( const basic_nsAReadableString<CharT>&, PRUint32 atPosition );
// virtual void InsertChar( CharT, PRUint32 atPosition ) = 0;
virtual void Cut( PRUint32 cutStart, PRUint32 cutLength );
virtual void Replace( PRUint32 cutStart, PRUint32 cutLength, const basic_nsAReadableString<CharT>& );
basic_nsAWritableString<CharT>&
operator+=( const basic_nsAReadableString<CharT>& rhs )
{
Append(rhs);
return *this;
}
basic_nsAWritableString<CharT>&
operator+=( const basic_nsLiteralString<CharT>& rhs )
{
Append(rhs);
return *this;
}
basic_nsAWritableString<CharT>&
operator=( const basic_nsAReadableString<CharT>& rhs )
{
Assign(rhs);
return *this;
}
basic_nsAWritableString<CharT>&
operator=( const basic_nsLiteralString<CharT>& rhs )
{
Assign(rhs);
return *this;
}
};
template <class CharT>
typename basic_nsAWritableString<CharT>::WritingIterator
copy_chunky( typename basic_nsAReadableString<CharT>::ReadingIterator first,
typename basic_nsAReadableString<CharT>::ReadingIterator last,
typename basic_nsAWritableString<CharT>::WritingIterator result )
{
while ( first != last )
{
PRUint32 lengthToCopy = PRUint32( NS_MIN(first.size_forward(), result.size_forward()) );
if ( first.fragment().mStart == last.fragment().mStart )
lengthToCopy = NS_MIN(lengthToCopy, PRUint32(last.operator->() - first.operator->()));
// assert(lengthToCopy > 0);
nsCharTraits<CharT>::copy(result.operator->(), first.operator->(), lengthToCopy);
first += PRInt32(lengthToCopy);
result += PRInt32(lengthToCopy);
}
return result;
}
template <class CharT>
typename basic_nsAWritableString<CharT>::WritingIterator
copy_backward_chunky( typename basic_nsAReadableString<CharT>::ReadingIterator first,
typename basic_nsAReadableString<CharT>::ReadingIterator last,
typename basic_nsAWritableString<CharT>::WritingIterator result )
{
while ( first != last )
{
PRUint32 lengthToCopy = PRUint32( NS_MIN(first.size_backward(), result.size_backward()) );
if ( first.fragment().mStart == last.fragment().mStart )
lengthToCopy = NS_MIN(lengthToCopy, PRUint32(first.operator->() - last.operator->()));
nsCharTraits<CharT>::move(result.operator->(), first.operator->(), lengthToCopy);
first -= PRInt32(lengthToCopy);
result -= PRInt32(lengthToCopy);
}
return result;
}
template <class CharT>
void
basic_nsAWritableString<CharT>::Assign( const basic_nsAReadableString<CharT>& rhs )
{
SetLength(rhs.Length());
copy_chunky<CharT>(rhs.BeginReading(), rhs.EndReading(), BeginWriting());
}
template <class CharT>
void
basic_nsAWritableString<CharT>::Append( const basic_nsAReadableString<CharT>& rhs )
{
PRUint32 oldLength = Length();
SetLength(oldLength + rhs.Length());
copy_chunky<CharT>(rhs.BeginReading(), rhs.EndReading(), BeginWriting(oldLength));
}
template <class CharT>
void
basic_nsAWritableString<CharT>::AppendChar( CharT aChar )
{
SetLength(Length()+1);
*EndWriting(1) = aChar;
}
template <class CharT>
void
basic_nsAWritableString<CharT>::Insert( const basic_nsAReadableString<CharT>& aReadable, PRUint32 aPosition )
{
PRUint32 oldLength = Length();
SetLength(oldLength + aReadable.Length());
if ( aPosition < oldLength )
copy_backward_chunky<CharT>(BeginReading(aPosition), BeginReading(oldLength), EndWriting());
else
aPosition = oldLength;
copy_chunky<CharT>(aReadable.BeginReading(), aReadable.EndReading(), BeginWriting(aPosition));
}
template <class CharT>
void
basic_nsAWritableString<CharT>::Cut( PRUint32 cutStart, PRUint32 cutLength )
{
copy_chunky<CharT>(BeginReading(cutStart+cutLength), EndReading(), BeginWriting(cutStart));
SetLength(Length()-cutLength);
}
template <class CharT>
void
basic_nsAWritableString<CharT>::Replace( PRUint32 cutStart, PRUint32 cutLength, const basic_nsAReadableString<CharT>& aReplacement )
{
PRUint32 oldLength = Length();
cutStart = NS_MIN(cutStart, oldLength);
cutLength = NS_MIN(cutLength, oldLength-cutStart);
PRUint32 cutEnd = cutStart + cutLength;
PRUint32 replacementLength = aReplacement.Length();
PRUint32 replacementEnd = cutStart + replacementLength;
PRUint32 newLength = oldLength - cutLength + replacementLength;
if ( cutLength > replacementLength )
copy_chunky<CharT>(BeginReading(cutEnd), EndReading(), BeginWriting(replacementEnd));
SetLength(newLength);
if ( cutLength < replacementLength )
copy_backward_chunky<CharT>(BeginReading(cutEnd), BeginReading(oldLength), BeginWriting(replacementEnd));
copy_chunky<CharT>(aReplacement.BeginReading(), aReplacement.EndReading(), BeginWriting(cutStart));
}
// operator>>
// getline (maybe)
typedef basic_nsAWritableString<PRUnichar> nsAWritableString;
typedef basic_nsAWritableString<char> nsAWritableCString;
#endif // !defined(_nsAWritableString_h__)