Add MatchHistory.View class (snapshot of history), refine one test, fix mistake in history.reset()

reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/MatchHistory.kt

@@ -22,13 +22,20 @@ import jetbrains.mps.logic.reactor.core.Occurrence
 import jetbrains.mps.logic.reactor.evaluation.RuleMatch
 import jetbrains.mps.logic.reactor.evaluation.StoreView
 import java.util.*
+import kotlin.collections.ArrayList
 
 
 interface MatchHistory {
+    data class View(val chunks: List<Chunk>, val nextChunkId: Int)
+
     data class Chunk(val match: RuleMatch, val id: Int, val justifications: TIntSet) {
-        data class Entry(val occ: Occurrence, val isDiscarded: Boolean = false)
+        data class Entry(val occ: Occurrence, val isDiscarded: Boolean = false) {
+            override fun toString() = (if (isDiscarded) '-' else '+') + occ.toString()
+        }
 
         var occurrences: MutableList<Entry> = mutableListOf()
+
+        override fun toString() = "(id=$id, $justifications, $occurrences)"
     }
 
     class RemoveChunkIterator(val it: MutableListIterator<Chunk>): Iterator<Chunk> by it {
@@ -44,6 +51,7 @@ interface MatchHistory {
     fun removeIterator(): RemoveChunkIterator
     fun resetStore()
     fun storeView(): StoreView
+    fun view(): MatchHistory.View
 
     fun logMatch(match: RuleMatch)
     fun logOccurence(occ: Occurrence)
@@ -56,12 +64,38 @@ interface MatchHistory {
     fun rollTo(futurePos: HistoryPos)
 
     companion object {
-        fun getMatchHistory(chunkIdSeed: Int = 0): MatchHistory = MatchHistoryImpl(chunkIdSeed)
+        fun fromSeed(chunkIdSeed: Int = 0): MatchHistory = MatchHistoryImpl(chunkIdSeed)
+        fun fromView(view: MatchHistory.View): MatchHistory = MatchHistoryImpl(view)
     }
 }
 
 
-internal class MatchHistoryImpl(chunkIdSeed: Int): MatchHistory {
+internal class MatchHistoryImpl(view: MatchHistory.View?): MatchHistory {
+
+    private val hist: MutableList<MatchHistory.Chunk>
+    private var nextChunkId: Int
+
+    //    private var order: Map<Chunk, Int> = emptyMap()
+    private val frameStack: FrameStack = FrameStack(null)
+
+    init {
+        if (view == null) {
+            hist = LinkedList<MatchHistory.Chunk>()
+            nextChunkId = 0
+        } else {
+            hist = LinkedList<MatchHistory.Chunk>(view.chunks)
+            nextChunkId = view.nextChunkId
+        }
+    }
+
+    constructor(chunkIdSeed: Int) : this(null) {
+        nextChunkId = chunkIdSeed
+    }
+
+    // FIXME: provide initial chunk? possibly initialized from StoreView, with empty justifications
+    private lateinit var current: MatchHistory.Chunk
+    private var pos: MutableListIterator<MatchHistory.Chunk> = hist.listIterator()
+
 
     override fun removeIterator() = MatchHistory.RemoveChunkIterator(hist.listIterator())
 
@@ -73,6 +107,8 @@ internal class MatchHistoryImpl(chunkIdSeed: Int): MatchHistory {
 
     override fun storeView(): StoreView = frameStack.current.store.view()
 
+    override fun view() = MatchHistory.View(ArrayList(hist), nextChunkId)
+
 
     override fun logMatch(match: RuleMatch) {
         val m = match as RuleMatchImpl
@@ -121,8 +157,9 @@ internal class MatchHistoryImpl(chunkIdSeed: Int): MatchHistory {
         val tp = timepoint as HistoryPosImpl
         frameStack.reset(tp.frame)
 
-        while (tp.chunk != current && pos.hasPrevious()) {
+        while (pos.hasPrevious()) {
             current = pos.previous()
+            if (current == tp.chunk) break
             pos.remove()
         }
         current.occurrences = current.occurrences.take(tp.occsRetained) as MutableList<MatchHistory.Chunk.Entry>
@@ -140,6 +177,7 @@ internal class MatchHistoryImpl(chunkIdSeed: Int): MatchHistory {
             rollOccurences(current.occurrences)
         }
     }
+
     fun rollTo(chunk: MatchHistory.Chunk) {
         while (current != chunk && pos.hasNext()) {
             current = pos.next()
@@ -162,17 +200,6 @@ internal class MatchHistoryImpl(chunkIdSeed: Int): MatchHistory {
 //    fun resetOrder() { order = hist.mapToIndex() }
 
 
-    private val hist: MutableList<MatchHistory.Chunk> = LinkedList<MatchHistory.Chunk>()
-//    private var order: Map<Chunk, Int> = emptyMap()
-    private val frameStack: FrameStack = FrameStack(null)
-
-    // FIXME: provide initial chunk? possibly initialized from StoreView, with empty justifications
-    private lateinit var current: MatchHistory.Chunk
-    private var pos: MutableListIterator<MatchHistory.Chunk> = hist.listIterator()
-
-    private var nextChunkId: Int = chunkIdSeed;
-
-
 }
 
 private fun RuleMatch.headJustifications(): TIntSet {

reactor/Test/test/TestMatchHistory.kt

@@ -1,10 +1,6 @@
 import gnu.trove.set.hash.TIntHashSet
 import jetbrains.mps.logic.reactor.core.*
-import jetbrains.mps.logic.reactor.core.internal.createOccurrenceMatcher
-import jetbrains.mps.logic.reactor.core.internal.logical
 import jetbrains.mps.logic.reactor.core.internal.MatchHistory
-import jetbrains.mps.logic.reactor.program.ConstraintSymbol
-import jetbrains.mps.logic.reactor.program.ConstraintSymbol.symbol
 import org.junit.Test
 import org.junit.Assert.*
 
@@ -29,7 +25,7 @@ class TestMatchHistory {
 
     @Test
     fun testJustificationTracking() {
-        val hist = MatchHistory.getMatchHistory()
+        val hist = MatchHistory.fromSeed()
 
         with(programWithRules(
             rule("rule1",
@@ -125,7 +121,7 @@ class TestMatchHistory {
 
     @Test
     fun testResetThenRoll() {
-        val hist = MatchHistory.getMatchHistory()
+        val hist = MatchHistory.fromSeed()
 
         with(programWithRules(
             rule("rule1",
@@ -198,7 +194,7 @@ class TestMatchHistory {
 
     @Test
     fun testPushExecReset() {
-        val hist = MatchHistory.getMatchHistory()
+        val hist = MatchHistory.fromSeed()
 
         with(programWithRules(
             rule("rule1",
@@ -274,6 +270,7 @@ class TestMatchHistory {
             hist.logOccurence(bazzOcc2)
             d = d.expand(bazzOcc2)
 
+            val oldState = hist.view()
             val oldStore = hist.storeView().allOccurrences()
             val savedPos = hist.currentPos()
             hist.push()
@@ -285,16 +282,20 @@ class TestMatchHistory {
 
             with(d.matches().first()) {
                 rule().tag() shouldBe "rule4"
+                hist.view().chunks.size shouldBe 2
                 hist.logMatch(this)
+                hist.view().chunks.size shouldBe 3
             }
             val lastOcc = occurrence("last")
             hist.logOccurence(lastOcc)
             d = d.expand(lastOcc)
 
 
+            assertNotEquals(oldState.chunks, hist.view().chunks)
             assertNotEquals(oldStore, hist.storeView().allOccurrences())
             hist.reset(savedPos)
-            assertEquals(oldStore, hist.storeView().allOccurrences())
+            hist.view().chunks shouldBe oldState.chunks
+            hist.storeView().allOccurrences() shouldBe oldStore
 
             hist.currentPos().chunk() shouldBe savedPos.chunk()
             hist.currentPos().occsRetained() shouldBe savedPos.occsRetained()