Package com.intellij.lexer

Interface RestartableLexer

public interface RestartableLexer

This interface is suitable for providing even distribution for restartable states in highlighting lexer implementation. Perfect highlighting lexer should be able to restart quickly from any context. Sometimes it's not enough to have only one restartable state in lexer logic. Implement isRestartableState(int) to provide several restartable states.

In some cases some additional information is needed to restart from non-trivial state. start(CharSequence, int, int, int, TokenIterator) implementation helps quickly retrieve information from preceding part of the file to restore lexer properly. LexerEditorHighlighter.documentChanged(DocumentEvent)

Method Summary

Modifier and Type	Method and Description
int	getStartState() Returns the start state of the lexer.
boolean	isRestartableState(int state) Specifies which states are restartable.
void	start(java.lang.CharSequence buffer, int startOffset, int endOffset, int initialState, TokenIterator tokenIterator) Extended form of Lexer.start(CharSequence, int, int, int) which provides an Iterable based on LexerEditorHighlighter.mySegments.

Method Detail

getStartState

int getStartState()

Returns the start state of the lexer.

Returns:

the lexer state.

isRestartableState

boolean isRestartableState(int state)

Specifies which states are restartable.

Parameters:

state - lexer state to check

Returns:

true if state is restartable, false otherwise.

start

void start(java.lang.CharSequence buffer,
           int startOffset,
           int endOffset,
           int initialState,
           TokenIterator tokenIterator)

Extended form of Lexer.start(CharSequence, int, int, int) which provides an Iterable based on LexerEditorHighlighter.mySegments. Iteration starts from current token and goes in reverse order. This iterable can be used for getting some additional data needed for context dependent restart.

Parameters:

buffer - character data for lexing

startOffset - offset to start lexing from

endOffset - offset to stop lexing at

initialState - state to start lexing with

tokenIterator - iterator for getting info from preceding tokens