commonMain.org.antlr.v4.kotlinruntime.atn.Transition.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.misc.IntervalSet
import kotlin.js.JsName
import kotlin.jvm.JvmField
/**
* An ATN transition between any two ATN states.
*
* Subclasses define atom, set, epsilon, action, predicate, rule transitions.
*
* This is a one way link. It emanates from a state (usually via a list of
* transitions) and has a target state.
*
* Since we never have to change the ATN transitions once we construct it,
* we can fix these transitions as specific classes. The DFA transitions
* on the other hand need to update the labels as it adds transitions to
* the states. We'll use the term Edge for the DFA to distinguish them from
* ATN transitions.
*
* @param target The target of this transition
*/
public abstract class Transition protected constructor(public var target: ATNState) {
public companion object {
// Constants for serialization
public const val EPSILON: Int = 1
public const val RANGE: Int = 2
public const val RULE: Int = 3
public const val PREDICATE: Int = 4 // e.g., {isType(input.LT(1))}?
public const val ATOM: Int = 5
public const val ACTION: Int = 6
public const val SET: Int = 7 // ~(A|B) or ~atom, wildcard, which convert to next 2
public const val NOT_SET: Int = 8
public const val WILDCARD: Int = 9
public const val PRECEDENCE: Int = 10
@JvmField
public val serializationNames: Array = arrayOf(
"INVALID",
"EPSILON",
"RANGE",
"RULE",
"PREDICATE",
"ATOM",
"ACTION",
"SET",
"NOT_SET",
"WILDCARD",
"PRECEDENCE",
)
}
public abstract val serializationType: Int
/**
* Determines if the transition is an "epsilon" transition.
*
* The default implementation returns `false`.
*
* @return `true` if traversing this transition in the ATN does not
* consume an input symbol, otherwise `false` if traversing this
* transition consumes (matches) an input symbol
*/
public open val isEpsilon: Boolean =
false
@JsName("getLabel")
public open fun label(): IntervalSet? =
null
public abstract fun matches(symbol: Int, minVocabSymbol: Int, maxVocabSymbol: Int): Boolean
}