Add total reset to repl history and state interfaces

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/repl/AggregatedReplState.kt

@@ -52,11 +52,19 @@ open class AggregatedReplStateHistory<T1, T2>(val history1: IReplStageHistory<T1
         ReplHistoryRecord(r1.id, r1.item to r2.item)
     }
 
+    override fun reset(): Iterable<ILineId> = lock.write {
+        assertSameSize()
+        val i1 = history1.reset().toList()
+        val i2 = history2.reset().toList()
+        if (i1 != i2) throw IllegalStateException("Aggregated history reset lines mismatch: $i1 != $i2")
+        i1
+    }
+
     override fun resetTo(id: ILineId): Iterable<ILineId> = lock.write {
         assertSameSize()
         val i1 = history1.resetTo(id).toList()
         val i2 = history2.resetTo(id).toList()
-        if (i1 != i2) throw IllegalStateException("Aggregated history resetted lines mismatch: $i1 != $i2")
+        if (i1 != i2) throw IllegalStateException("Aggregated history reset lines mismatch: $i1 != $i2")
         i1
     }
 

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/repl/BasicReplState.kt

@@ -49,6 +49,14 @@ open class BasicReplStageHistory<T>(override val lock: ReentrantReadWriteLock =
 
     override fun pop(): ReplHistoryRecord<T>? = lock.write { if (isEmpty()) null else removeAt(lastIndex) }
 
+    override fun reset(): Iterable<ILineId> {
+        lock.write {
+            val removed = map { it.id }
+            clear()
+            return removed
+        }
+    }
+
     override fun resetTo(id: ILineId): Iterable<ILineId> {
         lock.write {
             val idx = indexOfFirst { it.id == id }

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/repl/GenericReplCompilingEvaluator.kt

@@ -46,8 +46,13 @@ class GenericReplCompilingEvaluator(val compiler: ReplCompiler,
                             aggregatedState.apply {
                                 lock.write {
                                     if (state1.history.size > state2.history.size) {
-                                        state2.history.peek()?.let {
-                                            state1.history.resetTo(it.id)
+                                        if (state2.history.size == 0) {
+                                            state1.history.reset()
+                                        }
+                                        else {
+                                            state2.history.peek()?.let {
+                                                state1.history.resetTo(it.id)
+                                            }
                                         }
                                         assert(state1.history.size == state2.history.size)
                                     }

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/repl/ReplHistory.kt

@@ -52,6 +52,13 @@ class ReplHistory<T>(startingHistory: CompiledHistoryList<T> = emptyList()) : Se
         }
     }
 
+    /* resets back complete history and returns the lines removed */
+    fun reset(): SourceHistoryList<T> {
+        val removed = history.map { Pair(it.first.source, it.second) }
+        history.clear()
+        return removed
+    }
+
     /* resets back to a previous line number and returns the lines removed */
     fun resetToLine(lineNumber: Int): SourceHistoryList<T> {
         val removed = arrayListOf<SourceHistoryItem<T>>()

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/repl/ReplState.kt

@@ -41,6 +41,8 @@ interface IReplStageHistory<T> : List<ReplHistoryRecord<T>> {
         else null
     }
 
+    fun reset(): Iterable<ILineId>
+
     fun resetTo(id: ILineId): Iterable<ILineId>
 
     val lock: ReentrantReadWriteLock