Package org.aspectj.org.eclipse.jdt.core.compiler

Interface IScanner

All Known Implementing Classes:

PublicScanner

public interface IScanner

Caveat: With the introduction of "restricted keywords" in Java 9 it is impossible to classify a token without the help of a parser. For that reason, this interface is not suitable for scanning a modular compilation unit ("module-info.java"). It is the client's responsibility to pass only source from ordinary compilation units. For lack of a file name the scanner cannot check this.

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:

• invalid reference

  org.eclipse.jdt.core.ToolFactory

• ITerminalSymbols

Method Summary

Modifier and Type	Method	Description
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[]	getRawTokenSource()	Answers the current identifier source, before unicode escape sequences have been translated into unicode characters.
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 Details

getCurrentTokenSource

char[] getCurrentTokenSource()

Answers the current identifier source, after unicode escape sequences have been translated into unicode characters. For example, 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

getRawTokenSource

char[] getRawTokenSource()

Answers the current identifier source, before unicode escape sequences have been translated into unicode characters. For example, if original source was \\u0061bc then it will answer \\u0061bc.

Returns:

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

Since:

2.1

getCurrentTokenStartPosition

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

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

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 (in other words, 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

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 (in other words, 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

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

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

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 (for instance, 'assert' is a keyword in 1.4).

Returns:

the next token

Throws:

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

getSource

char[] getSource()

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

Returns:

the original source being processed

resetTo

void resetTo(int startPosition,
 int endPosition)

Reposition the scanner on some portion of the original source. The given endPosition is the last valid position. Beyond this position, the scanner will answer EOF tokens (ITerminalSymbols.TokenNameEOF).

Parameters:

startPosition - the given start position

endPosition - the given end position

setSource

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. If the given source is null, this clears the source.

Parameters:

source - the given source