org.eclipse.jdt.core.compiler
Interface IScanner

public interface IScanner

Definition of a Java scanner, as returned by the ToolFactory. The scanner is responsible for tokenizing a given source, providing information about the nature of the token read, its positions and source equivalent. When the scanner has finished tokenizing, it answers an EOF token ( ITerminalSymbols#TokenNameEOF. When encountering lexical errors, an InvalidInputException is thrown.

Since:

2.0

See Also:

ToolFactory, ITerminalSymbols

Method Summary

int	getCurrentTokenEndPosition() Answers the ending position of the current token inside the original source.
char[]	getCurrentTokenSource() Answers the current identifier source, after unicode escape sequences have been translated into unicode characters.
int	getCurrentTokenStartPosition() Answers the starting position of the current token inside the original source.
int	getLineEnd(int lineNumber) Answers the ending position of a given line number.
int[]	getLineEnds() Answers an array of the ending positions of the lines encountered so far.
int	getLineNumber(int charPosition) Answers a 1-based line number using the lines which have been encountered so far.
int	getLineStart(int lineNumber) Answers the starting position of a given line number.
int	getNextToken() Read the next token in the source, and answers its ID as specified by ITerminalSymbols.
char[]	getSource() Answers the original source being processed (not a copy of it).
void	resetTo(int startPosition, int endPosition) Reposition the scanner on some portion of the original source.
void	setSource(char[] source) Set the scanner source to process.

Method Detail

getCurrentTokenSource

public char[] getCurrentTokenSource()

Answers the current identifier source, after unicode escape sequences have been translated into unicode characters. e.g. if original source was \\u0061bc then it will answer abc.

Returns:

the current identifier source, after unicode escape sequences have been translated into unicode characters

getCurrentTokenStartPosition

public int getCurrentTokenStartPosition()

Answers the starting position of the current token inside the original source. This position is zero-based and inclusive. It corresponds to the position of the first character which is part of this token. If this character was a unicode escape sequence, it points at the first character of this sequence.

Returns:

the starting position of the current token inside the original source

getCurrentTokenEndPosition

public int getCurrentTokenEndPosition()

Answers the ending position of the current token inside the original source. This position is zero-based and inclusive. It corresponds to the position of the last character which is part of this token. If this character was a unicode escape sequence, it points at the last character of this sequence.

Returns:

the ending position of the current token inside the original source

getLineStart

public int getLineStart(int lineNumber)

Answers the starting position of a given line number. This line has to have been encountered already in the tokenization process (i.e. it cannot be used to compute positions of lines beyond current token). Once the entire source has been processed, it can be used without any limit. Line starting positions are zero-based, and start immediately after the previous line separator (if any).

Parameters:

lineNumber - the given line number

Returns:

the starting position of a given line number

getLineEnd

public int getLineEnd(int lineNumber)

Answers the ending position of a given line number. This line has to have been encountered already in the tokenization process (i.e. it cannot be used to compute positions of lines beyond current token). Once the entire source has been processed, it can be used without any limit. Line ending positions are zero-based, and correspond to the last character of the line separator (in case multi-character line separators).

Parameters:

lineNumber - the given line number

Returns:

the ending position of a given line number

getLineEnds

public int[] getLineEnds()

Answers an array of the ending positions of the lines encountered so far. Line ending positions are zero-based, and correspond to the last character of the line separator (in case multi-character line separators).

Returns:

an array of the ending positions of the lines encountered so far

getLineNumber

public int getLineNumber(int charPosition)

Answers a 1-based line number using the lines which have been encountered so far. If the position is located beyond the current scanned line, then the last line number will be answered.

Parameters:

charPosition - the given character position

Returns:

a 1-based line number using the lines which have been encountered so far

getNextToken

public int getNextToken()
                 throws InvalidInputException

Read the next token in the source, and answers its ID as specified by ITerminalSymbols. Note that the actual token ID values are subject to change if new keywords were added to the language (i.e. 'assert' keyword in 1.4).

Throws:

InvalidInputException - - in case a lexical error was detected while reading the current token

getSource

public char[] getSource()

Answers the original source being processed (not a copy of it).

Returns:

the original source being processed

resetTo

public void resetTo(int startPosition,
                    int endPosition)

Reposition the scanner on some portion of the original source. Once reaching the given endPosition it will answer EOF tokens (ITerminalSymbols.TokenNameEOF).

Parameters:

startPosition - the given start position

endPosition - the given end position

setSource

public void setSource(char[] source)

Set the scanner source to process. By default, the scanner will consider starting at the beginning of the source until it reaches its end.

Parameters:

source - the given source