commonMain.org.antlr.v4.kotlinruntime.atn.DecisionEventInfo.kt Maven / Gradle / Ivy
// Copyright 2017-present Strumenta and contributors, licensed under Apache 2.0.
// Copyright 2024-present Strumenta and contributors, licensed under BSD 3-Clause.
package org.antlr.v4.kotlinruntime.atn
import org.antlr.v4.kotlinruntime.TokenStream
/**
* This is the base class for gathering detailed information about prediction
* events which occur during parsing.
*
* Note that we could record the parser call stack at the time this event
* occurred but in the presence of left recursive rules, the stack is kind of
* meaningless. It's better to look at the individual configurations for their
* individual stacks. Of course that is a [PredictionContext] object
* not a parse tree node and so it does not have information about the extent
* (start...stop) of the various subtrees. Examining the stack tops of all
* configurations provide the return states for the rule invocations.
* From there you can get the enclosing rule.
*
* @since 4.3
*/
public open class DecisionEventInfo(
/**
* The invoked decision number which this event is related to.
*
* @see ATN.decisionToState
*/
public val decision: Int,
/**
* The configuration set containing additional information relevant to the
* prediction state when the current event occurred, or `null` if no
* additional information is relevant or available.
*/
public val configs: ATNConfigSet?,
/**
* The input token stream which is being parsed.
*/
public val input: TokenStream,
/**
* The token index in the input stream at which the current prediction was
* originally invoked.
*/
public val startIndex: Int,
/**
* The token index in the input stream at which the current event occurred.
*/
public val stopIndex: Int,
/**
* `true` if the current event occurred during LL prediction,
* otherwise `false` if the input occurred during SLL prediction.
*/
public val fullCtx: Boolean,
)