org.antlr.v4.runtime.atn

Interface LexerAction

All Known Implementing Classes:

LexerChannelAction, LexerCustomAction, LexerIndexedCustomAction, LexerModeAction, LexerMoreAction, LexerPopModeAction, LexerPushModeAction, LexerSkipAction, LexerTypeAction

public interface LexerAction

Represents a single action which can be executed following the successful match of a lexer rule. Lexer actions are used for both embedded action syntax and ANTLR 4's new lexer command syntax.

Since:

4.2

Author:

Sam Harwell

Method Summary

Methods

Modifier and Type	Method and Description
void	execute(Lexer lexer) Execute the lexer action in the context of the specified Lexer.
LexerActionType	getActionType() Gets the serialization type of the lexer action.
boolean	isPositionDependent() Gets whether the lexer action is position-dependent.

Method Detail

getActionType

LexerActionType getActionType()

Gets the serialization type of the lexer action.

Returns:

The serialization type of the lexer action.

isPositionDependent

boolean isPositionDependent()

Gets whether the lexer action is position-dependent. Position-dependent actions may have different semantics depending on the CharStream index at the time the action is executed.

Many lexer commands, including type, skip, and more, do not check the input index during their execution. Actions like this are position-independent, and may be stored more efficiently as part of the LexerATNConfig.lexerActionExecutor.

Returns:

true if the lexer action semantics can be affected by the position of the input CharStream at the time it is executed; otherwise, false.

execute

void execute(Lexer lexer)

Execute the lexer action in the context of the specified Lexer.

For position-dependent actions, the input stream must already be positioned correctly prior to calling this method.

Parameters:

lexer - The lexer instance.