Package org.exolab.castor.xml.dtd.parser
Class InputCharStream
- java.lang.Object
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- org.exolab.castor.xml.dtd.parser.InputCharStream
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- All Implemented Interfaces:
CharStream
public final class InputCharStream extends java.lang.Object implements CharStream
An implementation of interfaceCharStream
. Implements input character stream that maintains line and column number positions of the characters. It also has the capability to backup the stream to some extent.
The object of this class is constructed usingjava.io.Reader
reader and it is left to constructor of the reader to set up character encoding correctly. This means that method read of the reader is used to get next characters, assuming it returns appropriate values. It is recommended to use classjava.io.InputStreamReader
as a reader, which allows to set desired character encoding. This class is an intermediate component between input character reader and the parser.
The code of this class is based on the class ASCII_CharStream - implementation of interfaceCharStream
, that JavaCC would have generated with the following options set in a JavaCC grammar file:JAVA_UNICODE_ESCAPE = false; UNICODE_INPUT = false; USER_CHAR_STREAM = false;
Note that this class is not fully JavaCC generated.- Version:
- $Revision: 5962 $ $Date: 2003-03-03 00:05:44 -0700 (Mon, 03 Mar 2003) $
- Author:
- JavaCC, Alexander Totok
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Field Summary
Fields Modifier and Type Field Description (package private) int
available
int
bufpos
(package private) int
bufsize
static boolean
staticFlag
(package private) int
tokenBegin
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Constructor Summary
Constructors Constructor Description InputCharStream(java.io.Reader dstream)
Constructor, instantiating the char stream to begin at 1-st line and 1-st column of dstream.InputCharStream(java.io.Reader dstream, int startline, int startcolumn)
Constructor, allowing to specify start line and start column of the char stream.InputCharStream(java.io.Reader dstream, int startline, int startcolumn, int buffersize)
Constructor, allowing to specify start line and start column of the char stream, and buffer size as well.
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Method Summary
All Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description void
adjustBeginLineColumn(int newLine, int newCol)
Method to adjust line and column numbers for the start of a token.void
backup(int amount)
Backs up the input stream by amount steps.char
BeginToken()
Returns the next character that marks the beginning of the next token.void
Done()
The lexer calls this function to indicate that it is done with the stream and hence implementations can free any resources held by this class.int
getBeginColumn()
Returns the column number of the first character for current token (being matched after the last call to BeginTOken).int
getBeginLine()
Returns the line number of the first character for current token (being matched after the last call to BeginTOken).int
getColumn()
Deprecated.int
getEndColumn()
Returns the column number of the last character for current token (being matched after the last call to BeginTOken).int
getEndLine()
Returns the line number of the last character for current token (being matched after the last call to BeginTOken).java.lang.String
GetImage()
Returns a string made up of characters from the marked token beginning to the current buffer position.int
getLine()
Deprecated.char[]
GetSuffix(int len)
Returns an array of characters that make up the suffix of length 'len' for the currently matched token.char
readChar()
Returns the next character from the input stream.void
ReInit(java.io.Reader dstream)
Reinitialization of the char stream, instantiating the char stream to begin at 1-st line and 1-st column of dstream.void
ReInit(java.io.Reader dstream, int startline, int startcolumn)
Reinitialization of the char stream, allowing to specify start line and start column of the char stream.void
ReInit(java.io.Reader dstream, int startline, int startcolumn, int buffersize)
Reinitialization of the char stream, allowing to specify start line and start column of the char stream, and buffer size as well.
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Field Detail
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staticFlag
public static final boolean staticFlag
- See Also:
- Constant Field Values
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bufsize
int bufsize
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available
int available
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tokenBegin
int tokenBegin
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bufpos
public int bufpos
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Constructor Detail
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InputCharStream
public InputCharStream(java.io.Reader dstream, int startline, int startcolumn, int buffersize)
Constructor, allowing to specify start line and start column of the char stream, and buffer size as well.
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InputCharStream
public InputCharStream(java.io.Reader dstream, int startline, int startcolumn)
Constructor, allowing to specify start line and start column of the char stream.
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InputCharStream
public InputCharStream(java.io.Reader dstream)
Constructor, instantiating the char stream to begin at 1-st line and 1-st column of dstream.
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Method Detail
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BeginToken
public final char BeginToken() throws java.io.IOException
Description copied from interface:CharStream
Returns the next character that marks the beginning of the next token. All characters must remain in the buffer between two successive calls to this method to implement backup correctly.- Specified by:
BeginToken
in interfaceCharStream
- Throws:
java.io.IOException
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readChar
public final char readChar() throws java.io.IOException
Returns the next character from the input stream. The only method whose implementation is different from its original in the ASCII_CharStream class.- Specified by:
readChar
in interfaceCharStream
- Throws:
java.io.IOException
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getColumn
public final int getColumn()
Deprecated.Description copied from interface:CharStream
Returns the column position of the character last read.- Specified by:
getColumn
in interfaceCharStream
- See Also:
getEndColumn()
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getLine
public final int getLine()
Deprecated.Description copied from interface:CharStream
Returns the line number of the character last read.- Specified by:
getLine
in interfaceCharStream
- See Also:
getEndLine()
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getEndColumn
public final int getEndColumn()
Description copied from interface:CharStream
Returns the column number of the last character for current token (being matched after the last call to BeginTOken).- Specified by:
getEndColumn
in interfaceCharStream
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getEndLine
public final int getEndLine()
Description copied from interface:CharStream
Returns the line number of the last character for current token (being matched after the last call to BeginTOken).- Specified by:
getEndLine
in interfaceCharStream
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getBeginColumn
public final int getBeginColumn()
Description copied from interface:CharStream
Returns the column number of the first character for current token (being matched after the last call to BeginTOken).- Specified by:
getBeginColumn
in interfaceCharStream
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getBeginLine
public final int getBeginLine()
Description copied from interface:CharStream
Returns the line number of the first character for current token (being matched after the last call to BeginTOken).- Specified by:
getBeginLine
in interfaceCharStream
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backup
public final void backup(int amount)
Description copied from interface:CharStream
Backs up the input stream by amount steps. Lexer calls this method if it had already read some characters, but could not use them to match a (longer) token. So, they will be used again as the prefix of the next token and it is the implemetation's responsibility to do this right.- Specified by:
backup
in interfaceCharStream
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ReInit
public void ReInit(java.io.Reader dstream, int startline, int startcolumn, int buffersize)
Reinitialization of the char stream, allowing to specify start line and start column of the char stream, and buffer size as well.
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ReInit
public void ReInit(java.io.Reader dstream, int startline, int startcolumn)
Reinitialization of the char stream, allowing to specify start line and start column of the char stream.
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ReInit
public void ReInit(java.io.Reader dstream)
Reinitialization of the char stream, instantiating the char stream to begin at 1-st line and 1-st column of dstream.
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GetImage
public final java.lang.String GetImage()
Description copied from interface:CharStream
Returns a string made up of characters from the marked token beginning to the current buffer position. Implementations have the choice of returning anything that they want to. For example, for efficiency, one might decide to just return null, which is a valid implementation.- Specified by:
GetImage
in interfaceCharStream
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GetSuffix
public final char[] GetSuffix(int len)
Description copied from interface:CharStream
Returns an array of characters that make up the suffix of length 'len' for the currently matched token. This is used to build up the matched string for use in actions in the case of MORE. A simple and inefficient implementation of this is as follows :{ String t = GetImage(); return t.substring(t.length() - len, t.length()).toCharArray(); }
- Specified by:
GetSuffix
in interfaceCharStream
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Done
public void Done()
Description copied from interface:CharStream
The lexer calls this function to indicate that it is done with the stream and hence implementations can free any resources held by this class. Again, the body of this function can be just empty and it will not affect the lexer's operation.- Specified by:
Done
in interfaceCharStream
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adjustBeginLineColumn
public void adjustBeginLineColumn(int newLine, int newCol)
Method to adjust line and column numbers for the start of a token.
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