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// 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.misc
import com.strumenta.antlrkotlin.runtime.ext.appendCodePoint
import org.antlr.v4.kotlinruntime.Lexer
import org.antlr.v4.kotlinruntime.Token
import org.antlr.v4.kotlinruntime.Vocabulary
import kotlin.jvm.JvmField
/**
* This class implements the [IntSet] backed by a sorted array of
* non-overlapping intervals. It is particularly efficient for representing
* large collections of numbers, where the majority of elements appear as part
* of a sequential range of numbers that are all part of the set. For example,
* the set `{ 1, 2, 3, 4, 7, 8 }` may be represented as `{ [1, 4], [7, 8] }`.
*
* This class is able to represent sets containing any combination of values in
* the range [Int.MIN_VALUE] to [Int.MAX_VALUE] (inclusive).
*/
@Suppress("LocalVariableName")
public class IntervalSet : IntSet {
public companion object {
@JvmField
public val COMPLETE_CHAR_SET: IntervalSet = of(Lexer.MIN_CHAR_VALUE, Lexer.MAX_CHAR_VALUE).also {
it.isReadonly = true
}
@JvmField
public val EMPTY_SET: IntervalSet = IntervalSet().also {
it.isReadonly = true
}
/**
* Create a set with a single element, [a].
*/
public fun of(a: Int): IntervalSet {
val s = IntervalSet()
s.add(a)
return s
}
/**
* Create a set with all int(s) within range `a..b` (inclusive).
*/
public fun of(a: Int, b: Int): IntervalSet {
val s = IntervalSet()
s.add(a, b)
return s
}
/**
* Combine all sets in the array returned the or'd value.
*/
public fun or(vararg sets: IntervalSet): IntervalSet {
val r = IntervalSet()
for (s in sets) {
r.addAll(s)
}
return r
}
/**
* Compute the set difference between two interval sets.
*
* The specific operation is `left - right`.
* If either of the input sets is `null`, it is treated as though it was an empty set.
*/
public fun subtract(left: IntervalSet, right: IntervalSet): IntervalSet {
if (left.isNil) {
return IntervalSet()
}
val result = IntervalSet(left)
if (right.isNil) {
// Right set has no elements; just return the copy of the current set
return result
}
var resultI = 0
var rightI = 0
while (resultI < result._intervals.size && rightI < right._intervals.size) {
val resultInterval = result._intervals[resultI]
val rightInterval = right._intervals[rightI]
// Operation: (resultInterval - rightInterval) and update indexes
if (rightInterval.b < resultInterval.a) {
rightI++
continue
}
if (rightInterval.a > resultInterval.b) {
resultI++
continue
}
var beforeCurrent: Interval? = null
var afterCurrent: Interval? = null
if (rightInterval.a > resultInterval.a) {
beforeCurrent = Interval(resultInterval.a, rightInterval.a - 1)
}
if (rightInterval.b < resultInterval.b) {
afterCurrent = Interval(rightInterval.b + 1, resultInterval.b)
}
if (beforeCurrent != null) {
if (afterCurrent != null) {
// Split the current interval into two
result._intervals[resultI] = beforeCurrent
result._intervals.add(resultI + 1, afterCurrent)
resultI++
rightI++
continue
} else {
// Replace the current interval
result._intervals[resultI] = beforeCurrent
resultI++
continue
}
} else {
if (afterCurrent != null) {
// Replace the current interval
result._intervals[resultI] = afterCurrent
rightI++
continue
} else {
// Remove the current interval (thus no need to increment resultI)
result._intervals.removeAt(resultI)
continue
}
}
}
// If rightI reached right.intervals.size(), no more intervals to subtract from result.
// If resultI reached result.intervals.size(), we would be subtracting from an empty set.
// Either way, we are done.
return result
}
}
private val _intervals: MutableList
/**
* The list of sorted, disjoint intervals.
*/
public val intervals: List
get() = _intervals
override val isNil: Boolean
get() = _intervals.size == 0
/**
* Returns the maximum value contained in the set if not [isNil].
*
* @return The maximum value contained in the set
* @throws RuntimeException If set is empty
*/
public val maxElement: Int
get() {
if (isNil) {
throw RuntimeException("set is empty")
}
val last = _intervals[_intervals.size - 1]
return last.b
}
/**
* Returns the minimum value contained in the set if not [isNil].
*
* @return The minimum value contained in the set
* @throws RuntimeException If set is empty
*/
public val minElement: Int
get() {
if (isNil) {
throw RuntimeException("set is empty")
}
return _intervals[0].a
}
public var isReadonly: Boolean = false
set(value) {
if (field && !value) {
throw IllegalStateException("can't alter readonly IntervalSet")
}
field = value
}
// This is the most used constructor.
// Before, the vararg one was getting used, allocating an IntArray for no reason
public constructor() {
// The initial size of 16 is a best guess by evaluating
// the size when executed under multiple grammars
_intervals = ArrayList(16)
}
public constructor(intervals: MutableList) {
_intervals = intervals
}
public constructor(set: IntervalSet) {
_intervals = ArrayList(set._intervals.size)
addAll(set)
}
public fun clear() {
if (isReadonly) {
throw IllegalStateException("can't alter readonly IntervalSet")
}
_intervals.clear()
}
/**
* Add a single element to the set.
*
* An isolated element is stored as a range `el..el`.
*/
override fun add(el: Int): Unit =
add(el, el)
/**
* Add interval; i.e., add all integers from a to b to set.
*
* If `b < a`, do nothing.
* Keep list in sorted order (by left range value).
* If there is overlap, combine ranges. For example,
* if this is `{1..5, 10..20}`, adding `6..7` yields
* `{1..5, 6..7, 10..20}`. Adding `4..8` yields `{1..8, 10..20}`.
*/
public fun add(a: Int, b: Int): Unit =
add(Interval.of(a, b))
// Copy on write, so we can cache a..a intervals and sets of that
private fun add(addition: Interval) {
if (isReadonly) {
throw IllegalStateException("can't alter readonly IntervalSet")
}
if (addition.b < addition.a) {
return
}
// Find position in list.
// Use iterators as we modify list in place
val iter = _intervals.listIterator()
while (iter.hasNext()) {
val r = iter.next()
if (addition == r) {
return
}
if (addition.adjacent(r) || !addition.disjoint(r)) {
// Next to each other, make a single larger interval
val bigger = addition.union(r)
iter.set(bigger)
// Make sure we didn't just create an interval that
// should be merged with next interval in list
while (iter.hasNext()) {
val next = iter.next()
if (!bigger.adjacent(next) && bigger.disjoint(next)) {
break
}
// If we bump up against or overlap next, merge
iter.remove() // Remove this one
iter.previous() // Move backwards to what we just set
iter.set(bigger.union(next)) // Set to 3 merged ones
iter.next() // First call to next after previous duplicates the result
}
return
}
if (addition.startsBeforeDisjoint(r)) {
// Insert before r
iter.previous()
iter.add(addition)
return
}
// If disjoint and after r, a future iteration will handle it
}
// Ok, must be after last interval (and disjoint from last interval), just add it
_intervals.add(addition)
}
override fun addAll(set: IntSet): IntervalSet {
if (set is IntervalSet) {
// Walk set and add each interval
val setIntervals = set._intervals
for (i in 0.. el) {
r = m - 1
} else { // el >= a && el <= b
return true
}
}
return false
}
override fun hashCode(): Int {
var hash = MurmurHash.initialize()
for (I in _intervals) {
hash = MurmurHash.update(hash, I.a)
hash = MurmurHash.update(hash, I.b)
}
hash = MurmurHash.finish(hash, _intervals.size * 2)
return hash
}
/**
* Are two `IntervalSets` equal? Because all intervals are sorted
* and disjoint, equals is a simple linear walk over both lists
* to make sure they are the same.
*
* [Interval.equals] is used by the [List.equals] method to check the ranges.
*/
override fun equals(other: Any?): Boolean =
other is IntervalSet && _intervals == other._intervals
override fun toString(): String =
toString(false)
public fun toString(elemAreChar: Boolean): String {
if (_intervals.isEmpty()) {
return "{}"
}
val buf = StringBuilder(64)
if (size() > 1) {
buf.append("{")
}
val n = _intervals.size
var index = 0
while (index < n) {
val I = _intervals[index++]
val a = I.a
val b = I.b
if (a == b) {
if (a == Token.EOF) {
buf.append("")
} else if (elemAreChar) {
buf.append("'")
buf.appendCodePoint(a)
buf.append("'")
} else {
buf.append(a)
}
} else {
if (elemAreChar) {
buf.append("'")
buf.appendCodePoint(a)
buf.append("'..'")
buf.appendCodePoint(b)
buf.append("'")
} else {
buf.append(a)
buf.append("..")
buf.append(b)
}
}
if (index < n) {
buf.append(", ")
}
}
if (size() > 1) {
buf.append("}")
}
return buf.toString()
}
public fun toString(vocabulary: Vocabulary): String {
if (_intervals.isEmpty()) {
return "{}"
}
val buf = StringBuilder(64)
if (size() > 1) {
buf.append("{")
}
val n = _intervals.size
var index = 0
while (index < n) {
val I = _intervals[index++]
val a = I.a
val b = I.b
if (a == b) {
buf.append(elementName(vocabulary, a))
} else {
for (p in a..b) {
if (p > a) {
buf.append(", ")
}
buf.append(elementName(vocabulary, p))
}
}
if (index < n) {
buf.append(", ")
}
}
if (size() > 1) {
buf.append("}")
}
return buf.toString()
}
private fun elementName(vocabulary: Vocabulary, a: Int): String =
when (a) {
Token.EOF -> ""
Token.EPSILON -> ""
else -> vocabulary.getDisplayName(a)
}
override fun size(): Int {
val numIntervals = _intervals.size
if (numIntervals == 1) {
val firstInterval = _intervals[0]
return firstInterval.b - firstInterval.a + 1
}
var n = 0
for (i in 0.. {
val values = ArrayList(32)
val n = _intervals.size
for (i in 0.. {
val s = HashSet(32)
for (I in _intervals) {
val a = I.a
val b = I.b
for (v in a..b) {
s.add(v)
}
}
return s
}
/**
* Get the ith element of ordered set.
*
* Used only by `RandomPhrase` so don't bother to implement
* if you're not doing that for a new ANTLR code gen target.
*/
public operator fun get(i: Int): Int {
val n = _intervals.size
var index = 0
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