Package eu.bandm.tools.lexic

Class LocationCodePointSource<D>

java.lang.Object

eu.bandm.tools.lexic.LocationCodePointSource<D>

Type Parameters:

D - the type of document identifiers

All Implemented Interfaces:

CodePointSource, IntSupplier

public class LocationCodePointSource<D>
extends Object
implements CodePointSource

A secondary code point source that tracks location information.

Code points are obtained from another code point source. For the consistency of the computed location information, it is required that the are no other, concurrent consumers of code points from that source.

For tracking line and column number information, the following ISO control characters are recognized:

'\n'

advances the line number and resets the column number

'\r'

no effect

'\f'

no effect

'\t'

advances the column number to the next tab stop

Other ISO control characters must not occur among the input code points, or a IllegalArgumentException is thrown.

See Also:

• Character.isISOControl(char)

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DEFAULT_TAB_WIDTH	The default width of tab stops.

Constructor Summary

Constructors

Constructor	Description
LocationCodePointSource(CodePointSource input, D documentId, int firstLine, int firstColumn)	Creates a new instance.

Method Summary

Modifier and Type	Method	Description
void	clearBeginPoint()	Erases the recorded interval begin point.
int	getAsInt()	Returns the next code point if available.
Location<D>	getPoint()	Returns a location that points to the current input position.
Location<D>	getRegion()	Returns a location that spans the interval from the previously recorded begin point to the current position.
void	setBeginPoint()	Records the current input position as the beginning of an interval.
void	setTabWidth(int tabWidth)	Sets the width of tab stops.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DEFAULT_TAB_WIDTH

public static final int DEFAULT_TAB_WIDTH

The default width of tab stops. The value is 1, such that tabs count as single spaces.

See Also:

• Constant Field Values

Constructor Details

LocationCodePointSource

public LocationCodePointSource(CodePointSource input,
 @Opt
 D documentId,
 int firstLine,
 int firstColumn)

Creates a new instance.

Parameters:

input - the input code point source

documentId - the identifier of the underlying document, or null if not available

firstLine - the non-negative first line number of the underlying document, or one of the special values Location.UNKNOWN or Location.NOT_APPLICABLE

firstColumn - the non-negative first column number of each line of the underlying document, or one of the special values Location.UNKNOWN or Location.NOT_APPLICABLE

See Also:

• Location

Method Details

getPoint

public Location<D> getPoint()

Returns a location that points to the current input position.

Returns:

a location that points to the current input position

setBeginPoint

public void setBeginPoint()

Records the current input position as the beginning of an interval.

See Also:

• getRegion()
• clearBeginPoint()

clearBeginPoint

public void clearBeginPoint()

Erases the recorded interval begin point.

See Also:

• setBeginPoint()
• getRegion()

getRegion

public Location<D> getRegion()

Returns a location that spans the interval from the previously recorded begin point to the current position.

Returns:

a location that spans the interval from the previously recorded begin point to the current position

Throws:

IllegalStateException - if the begin point has not been set

See Also:

• setBeginPoint()
• clearBeginPoint()

getAsInt

public int getAsInt()

Returns the next code point if available.

Specified by:

getAsInt in interface CodePointSource

Specified by:

getAsInt in interface IntSupplier

Returns:

either a valid Unicode code point, or -1 to indicate that the end of the stream has been reached

Throws:

IllegalArgumentException - if a code point is encountered that denotes any ISO control character other than the recognized ones

See Also:

• Character.isISOControl(char)

setTabWidth

public void setTabWidth(int tabWidth)

Sets the width of tab stops.

Parameters:

tabWidth - the new width of tab stops

Throws:

IllegalArgumentException - if the given width is non-positive