Package org.jparsec

Class SourceLocator

java.lang.Object

org.jparsec.SourceLocator

final class SourceLocator
extends Object

Locates the line and column number of a 0-based index in the source.

This class internally keeps a cache of the indices of all the line break characters scanned so far, therefore repeated location lookup can be done in amortized log(n) time.

It is not multi-thread safe.

Field Summary

Fields

Modifier and Type	Field	Description
private static final char	LINE_BREAK	The line break character.
(package private) final IntList	lineBreakIndices	The 0-based indices of the line break characters scanned so far.
(package private) int	nextColumnIndex	The 0-based index of the column of the next character to be scanned.
(package private) int	nextIndex	The 0-based index of the next character to be scanned.
private final CharSequence	source
private final int	startColumnNumber	The first column number.
private final int	startLineNumber	The first line number.

Constructor Summary

Constructors

Constructor	Description
SourceLocator(CharSequence source)	Creates a SourceLocator object.
SourceLocator(CharSequence source, int lineNumber, int columnNumber)	Creates a SourceLocator object.

Method Summary

Modifier and Type	Method	Description
(package private) static int	binarySearch(IntList ascendingInts, int value)	Uses binary search to look up the index of the first element in ascendingInts that's greater than or equal to value.
private int	getLineBreakColumnIndex(int lineIndex)	Gets the 0-based column number of the line break character for line identified by lineIndex.
private Location	getLineBreakLocation(int lineIndex)
(package private) Location	locate(int index)
private Location	location(int l, int c)
(package private) Location	lookup(int index)	Looks up the location identified by ind using the cached indices of line break characters.
(package private) Location	scanTo(int index)	Scans from nextIndex to ind and saves all indices of line break characters into lineBreakIndices and adjusts the current column number as it goes.

Methods inherited from class java.lang.Object

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

Field Details

LINE_BREAK

private static final char LINE_BREAK

The line break character.

See Also:

• Constant Field Values

source

private final CharSequence source

lineBreakIndices

final IntList lineBreakIndices

The 0-based indices of the line break characters scanned so far.

startLineNumber

private final int startLineNumber

The first line number.

startColumnNumber

private final int startColumnNumber

The first column number.

nextIndex

int nextIndex

The 0-based index of the next character to be scanned.

nextColumnIndex

int nextColumnIndex

The 0-based index of the column of the next character to be scanned.

Constructor Details

SourceLocator

SourceLocator(CharSequence source)

Creates a SourceLocator object.

Parameters:

source - the source.

SourceLocator

SourceLocator(CharSequence source,
 int lineNumber,
 int columnNumber)

Creates a SourceLocator object.

Parameters:

source - the source.

lineNumber - the starting line number.

columnNumber - the starting column number.

Method Details

locate

Location locate(int index)

lookup

Location lookup(int index)

Looks up the location identified by ind using the cached indices of line break characters. This assumes that all line-break characters before ind are already scanned.

scanTo

Location scanTo(int index)

Scans from nextIndex to ind and saves all indices of line break characters into lineBreakIndices and adjusts the current column number as it goes. The location of the character on ind is returned.

After this method returns, nextIndex and nextColumnIndex will point to the next character to be scanned or the EOF if the end of input is encountered.

getLineBreakColumnIndex

private int getLineBreakColumnIndex(int lineIndex)

Gets the 0-based column number of the line break character for line identified by lineIndex.

getLineBreakLocation

private Location getLineBreakLocation(int lineIndex)

location

private Location location(int l,
 int c)

binarySearch

static int binarySearch(IntList ascendingInts,
 int value)

Uses binary search to look up the index of the first element in ascendingInts that's greater than or equal to value. If all elements are smaller than value, ascendingInts.size() is returned.