gecko-dev/htmlparser/src/nsScanner.h

356 lines
10 KiB
C++

/* -*- 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):
*/
/**
* MODULE NOTES:
* @update gess 4/1/98
*
* The scanner is a low-level service class that knows
* how to consume characters out of an (internal) stream.
* This class also offers a series of utility methods
* that most tokenizers want, such as readUntil(),
* readWhile() and SkipWhitespace().
*/
#ifndef SCANNER
#define SCANNER
#include "nsString.h"
#include "nsIParser.h"
#include "prtypes.h"
#include "nsIUnicodeDecoder.h"
#include "nsFileStream.h"
class nsScanner {
public:
/**
* Use this constructor if you want i/o to be based on
* a single string you hand in during construction.
* This short cut was added for Javascript.
*
* @update ftang 3/02/99
* @param aCharset charset
* @param aCharsetSource - where the charset info came from
* @param aMode represents the parser mode (nav, other)
* @return
*/
nsScanner(nsString& anHTMLString, const nsString& aCharset, nsCharsetSource aSource);
/**
* Use this constructor if you want i/o to be based on
* a file (therefore a stream) or just data you provide via Append().
*
* @update ftang 3/02/99
* @param aCharset charset
* @param aCharsetSource - where the charset info came from
* @param aMode represents the parser mode (nav, other)
* @return
*/
nsScanner(nsString& aFilename,PRBool aCreateStream, const nsString& aCharset, nsCharsetSource aSource);
/**
* Use this constructor if you want i/o to be stream based.
*
* @update ftang 3/02/99
* @param aCharset charset
* @param aCharsetSource - where the charset info came from
* @param aMode represents the parser mode (nav, other)
* @return
*/
nsScanner(nsString& aFilename, nsInputStream& aStream, const nsString& aCharset, nsCharsetSource aSource);
~nsScanner();
/**
* retrieve next char from internal input stream
*
* @update gess 3/25/98
* @param ch is the char to accept new value
* @return error code reflecting read status
*/
nsresult GetChar(PRUnichar& ch);
/**
* peek ahead to consume next char from scanner's internal
* input buffer
*
* @update gess 3/25/98
* @param ch is the char to accept new value
* @return error code reflecting read status
*/
nsresult Peek(PRUnichar& ch);
/**
* Push the given char back onto the scanner
*
* @update gess 3/25/98
* @param character to be pushed
* @return error code
*/
nsresult PutBack(PRUnichar ch);
/**
* Skip over chars as long as they're in aSkipSet
*
* @update gess 3/25/98
* @param set of chars to be skipped
* @return error code
*/
nsresult SkipOver(nsString& SkipChars);
/**
* Skip over chars as long as they equal given char
*
* @update gess 3/25/98
* @param char to be skipped
* @return error code
*/
nsresult SkipOver(PRUnichar aSkipChar);
/**
* Skip over chars until they're in aValidSet
*
* @update gess 3/25/98
* @param aValid set contains chars you're looking for
* @return error code
*/
nsresult SkipTo(nsString& aValidSet);
/**
* Skip over chars as long as they're in aSequence
*
* @update gess 3/25/98
* @param contains sequence to be skipped
* @return error code
*/
nsresult SkipPast(nsString& aSequence);
/**
* Skip whitespace on scanner input stream
*
* @update gess 3/25/98
* @return error status
*/
nsresult SkipWhitespace(void);
/**
* Determine if the scanner has reached EOF.
* This method can also cause the buffer to be filled
* if it happens to be empty
*
* @update gess 3/25/98
* @return PR_TRUE upon eof condition
*/
nsresult Eof(void);
/**
* Consume characters until you find the terminal char
*
* @update gess 3/25/98
* @param aString receives new data from stream
* @param addTerminal tells us whether to append terminal to aString
* @return error code
*/
nsresult GetIdentifier(nsSubsumeStr& aString,PRBool allowPunct=PR_FALSE);
nsresult ReadIdentifier(nsString& aString,PRBool allowPunct=PR_FALSE);
nsresult ReadNumber(nsString& aString);
nsresult ReadWhitespace(nsString& aString);
/**
* Consume characters until you find the terminal char
*
* @update gess 3/25/98
* @param aString receives new data from stream
* @param aTerminal contains terminating char
* @param addTerminal tells us whether to append terminal to aString
* @return error code
*/
nsresult ReadUntil(nsString& aString,PRUnichar aTerminal,PRBool addTerminal);
/**
* Consume characters until you find one contained in given
* terminal set.
*
* @update gess 3/25/98
* @param aString receives new data from stream
* @param aTermSet contains set of terminating chars
* @param addTerminal tells us whether to append terminal to aString
* @return error code
*/
nsresult ReadUntil(nsString& aString,nsString& aTermSet,PRBool addTerminal);
nsresult ReadUntil(nsString& aString,nsCString& aTermSet,PRBool addTerminal);
nsresult ReadUntil(nsString& aString,const char* aTermSet,PRBool addTerminal);
/**
* Consume characters while they're members of anInputSet
*
* @update gess 3/25/98
* @param aString receives new data from stream
* @param anInputSet contains valid chars
* @param addTerminal tells us whether to append terminal to aString
* @return error code
*/
nsresult ReadWhile(nsString& aString,nsString& anInputSet,PRBool addTerminal);
/**
* Records current offset position in input stream. This allows us
* to back up to this point if the need should arise, such as when
* tokenization gets interrupted.
*
* @update gess 5/12/98
* @param
* @return
*/
PRUint32 Mark(PRInt32 anIndex=-1);
/**
* Resets current offset position of input stream to marked position.
* This allows us to back up to this point if the need should arise,
* such as when tokenization gets interrupted.
* NOTE: IT IS REALLY BAD FORM TO CALL RELEASE WITHOUT CALLING MARK FIRST!
*
* @update gess 5/12/98
* @param
* @return
*/
PRUint32 RewindToMark(void);
/**
*
*
* @update harishd 01/12/99
* @param
* @return
*/
PRBool Insert(const nsAReadableString& aBuffer);
/**
*
*
* @update gess 5/13/98
* @param
* @return
*/
PRBool Append(const nsAReadableString& aBuffer);
/**
*
*
* @update gess 5/21/98
* @param
* @return
*/
PRBool Append(const char* aBuffer, PRUint32 aLen);
PRBool Append(const PRUnichar* aBuffer, PRUint32 aLen);
/**
*
*
* @update gess 5/12/98
* @param
* @return
*/
nsString& GetBuffer(void);
/**
* Call this to copy bytes out of the scanner that have not yet been consumed
* by the tokenization process.
*
* @update gess 5/12/98
* @param aCopyBuffer is where the scanner buffer will be copied to
* @return nada
*/
void CopyUnusedData(nsString& aCopyBuffer);
/**
* Retrieve the name of the file that the scanner is reading from.
* In some cases, it's just a given name, because the scanner isn't
* really reading from a file.
*
* @update gess 5/12/98
* @return
*/
nsString& GetFilename(void);
static void SelfTest();
/**
* Use this setter to change the scanner's unicode decoder
*
* @update ftang 3/02/99
* @param aCharset a normalized (alias resolved) charset name
* @param aCharsetSource- where the charset info came from
* @return
*/
nsresult SetDocumentCharset(const nsString& aCharset, nsCharsetSource aSource);
/**
* Internal method used to cause the internal buffer to
* be filled with data.
*
* @update gess4/3/98
*/
PRBool IsIncremental(void) {return mIncremental;}
void SetIncremental(PRBool anIncrValue) {mIncremental=anIncrValue;}
PRUint32 GetOffset(void) {return mOffset;}
PRInt32 GetNewlinesSkipped(void) { return mNewlinesSkipped; }
protected:
enum {eBufferSizeThreshold=0x1000}; //4K
/**
* Internal method used to cause the internal buffer to
* be filled with data.
*
* @update gess4/3/98
*/
nsresult FillBuffer(void);
nsInputStream* mInputStream;
nsString mBuffer;
nsString mFilename;
PRUint32 mOffset;
PRUint32 mMarkPos;
PRUint32 mTotalRead;
PRBool mOwnsStream;
PRBool mIncremental;
nsCharsetSource mCharsetSource;
nsString mCharset;
nsIUnicodeDecoder *mUnicodeDecoder;
nsString mUnicodeXferBuf;
PRInt32 mNewlinesSkipped;
};
#endif