[6.0] New collection methods

core/shared/src/main/scala/sigma/Colls.scala

@@ -45,6 +45,19 @@ trait Coll[@specialized A] {
     */
   def apply(i: Int): A
 
+  /** The element at given index or None if there is no such element. Indices start at `0`.
+    *
+    *  @param  i       the index
+    *  @return         the element at the given index, or None if there is no such element
+    */
+  def get(i: Int): Option[A] = {
+    if (isDefinedAt(i)) {
+      Some(apply(i))
+    } else {
+      None
+    }
+  }
+
   /** Tests whether this $coll contains given index.
     *
     *  The implementations of methods `apply` and `isDefinedAt` turn a `Coll[A]` into
@@ -76,6 +89,18 @@ trait Coll[@specialized A] {
     * produces a collection ((x0, y0), ..., (xK, yK)) where K = min(N, M) */
   def zip[@specialized B](ys: Coll[B]): Coll[(A, B)]
 
+  /**
+    * @return true if first elements of this collection form given `ys` collection, false otherwise.
+    *         E.g. [1,2,3] starts with [1,2]
+    */
+  def startsWith(ys: Coll[A]): Boolean
+
+  /**
+    * @return true if last elements of this collection form given `ys` collection, false otherwise.
+    *         E.g. [1,2,3] ends with [2,3]
+    */
+  def endsWith(ys: Coll[A]): Boolean
+
   /** Tests whether a predicate holds for at least one element of this collection.
     *  @param   p     the predicate used to test elements.
     *  @return        `true` if the given predicate `p` is satisfied by at least one element of this collection, otherwise `false`

core/shared/src/main/scala/sigma/data/CollsOverArrays.scala

@@ -39,6 +39,10 @@ class CollOverArray[@specialized A](val toArray: Array[A], val builder: CollBuil
 
   @inline def zip[@specialized B](ys: Coll[B]): PairColl[A, B] = builder.pairColl(this, ys)
 
+  @inline def startsWith(ys: Coll[A]): Boolean = toArray.startsWith(ys.toArray)
+
+  @inline def endsWith(ys: Coll[A]): Boolean = toArray.endsWith(ys.toArray)
+
   def append(other: Coll[A]): Coll[A] = {
     if (toArray.length <= 0) return other
     val result = if (VersionContext.current.isJitActivated) {
@@ -350,6 +354,16 @@ class PairOfCols[@specialized L, @specialized R](val ls: Coll[L], val rs: Coll[R
 
   def zip[@specialized B](ys: Coll[B]): PairColl[(L,R), B] = builder.pairColl(this, ys)
 
+  def startsWith(ys: Coll[(L, R)]): Boolean = ys match {
+    case yp: PairOfCols[L, R] => ls.startsWith(yp.ls) && rs.startsWith(yp.rs)
+    case _ => toArray.startsWith(ys.toArray)
+  }
+
+  def endsWith(ys: Coll[(L, R)]): Boolean = ys match {
+    case yp: PairOfCols[L, R] => ls.endsWith(yp.ls) && rs.endsWith(yp.rs)
+    case _ => toArray.endsWith(ys.toArray)
+  }
+
   override def indices: Coll[Int] = if (ls.length <= rs.length) ls.indices else rs.indices
 
   override def flatMap[B: RType](f: ((L, R)) => Coll[B]): Coll[B] =

core/shared/src/main/scala/sigma/reflection/ReflectionData.scala

@@ -162,6 +162,9 @@ object ReflectionData {
         mkMethod(clazz, "apply", Array[Class[_]](classOf[Int])) { (obj, args) =>
           obj.asInstanceOf[Coll[_]].apply(args(0).asInstanceOf[Int])
         },
+        mkMethod(clazz, "get", Array[Class[_]](classOf[Int])) { (obj, args) =>
+          obj.asInstanceOf[Coll[_]].get(args(0).asInstanceOf[Int])
+        },
         mkMethod(clazz, "append", Array[Class[_]](classOf[Coll[_]])) { (obj, args) =>
           obj.asInstanceOf[Coll[Any]].append(args(0).asInstanceOf[Coll[Any]])
         },
@@ -170,6 +173,18 @@ object ReflectionData {
         },
         mkMethod(clazz, "map", Array[Class[_]](classOf[Function1[_, _]], classOf[RType[_]])) { (obj, args) =>
           obj.asInstanceOf[Coll[Any]].map(args(0).asInstanceOf[Any => Any])(args(1).asInstanceOf[RType[Any]])
+        },
+        mkMethod(clazz, "reverse", Array[Class[_]]()) { (obj, args) =>
+          obj.asInstanceOf[Coll[Any]].reverse
+        },
+        mkMethod(clazz, "distinct", Array[Class[_]]()) { (obj, args) =>
+          obj.asInstanceOf[Coll[Any]].distinct
+        },
+        mkMethod(clazz, "startsWith", Array[Class[_]](classOf[Coll[_]])) { (obj, args) =>
+          obj.asInstanceOf[Coll[Any]].startsWith(args(0).asInstanceOf[Coll[Any]])
+        },
+        mkMethod(clazz, "endsWith", Array[Class[_]](classOf[Coll[_]])) { (obj, args) =>
+          obj.asInstanceOf[Coll[Any]].endsWith(args(0).asInstanceOf[Coll[Any]])
         }
       )
     )

core/shared/src/test/scala/sigma/CollsTests.scala

@@ -386,6 +386,32 @@ class CollsTests extends AnyPropSpec with ScalaCheckPropertyChecks with Matchers
     }
   }
 
+  property("Coll.startsWith") {
+    val minSuccess = minSuccessful(50)
+    forAll(collGen, minSuccess) { col =>
+      val n = col.length / 2
+      val prefix = col.take(n)
+      val pairs = col.zip(col)
+      pairs.startsWith(prefix.zip(prefix)) shouldBe true
+      col.startsWith(prefix) shouldBe true
+      val pairOfCols = new PairOfCols[Int, Int](col, col)
+      pairOfCols.startsWith(pairOfCols.take(n)) shouldBe true
+    }
+  }
+
+  property("Coll.endsWith") {
+    val minSuccess = minSuccessful(50)
+    forAll(collGen, minSuccess) { col =>
+      val n = col.length / 2
+      val suffix = col.slice(n, col.length)
+      col.endsWith(suffix) shouldBe true
+      val pairs = col.zip(col)
+      pairs.endsWith(suffix.zip(suffix)) shouldBe true
+      val pairOfCols = new PairOfCols[Int, Int](col, col)
+      pairOfCols.endsWith(pairOfCols.slice(n, col.length)) shouldBe true
+    }
+  }
+
   property("Coll.equals") {
     def checkColls(repl: Coll[_], coll: Coll[_]) = {
       assert(coll == repl)

data/shared/src/main/scala/sigma/SigmaDataReflection.scala

@@ -317,6 +317,22 @@ object SigmaDataReflection {
         mkMethod(clazz, "flatMap_eval", Array[Class[_]](classOf[MethodCall], classOf[Coll[_]], classOf[Function1[_,_]], classOf[ErgoTreeEvaluator])) { (obj, args) =>
           obj.asInstanceOf[SCollectionMethods.type].flatMap_eval(args(0).asInstanceOf[MethodCall],
             args(1).asInstanceOf[Coll[Any]], args(2).asInstanceOf[Any => Coll[Any]])(args(3).asInstanceOf[ErgoTreeEvaluator])
+        },
+        mkMethod(clazz, "reverse_eval", Array[Class[_]](classOf[MethodCall], classOf[Coll[_]], classOf[ErgoTreeEvaluator])) { (obj, args) =>
+          obj.asInstanceOf[SCollectionMethods.type].reverse_eval(args(0).asInstanceOf[MethodCall],
+            args(1).asInstanceOf[Coll[Any]])(args(2).asInstanceOf[ErgoTreeEvaluator])
+        },
+        mkMethod(clazz, "distinct_eval", Array[Class[_]](classOf[MethodCall], classOf[Coll[_]], classOf[ErgoTreeEvaluator])) { (obj, args) =>
+          obj.asInstanceOf[SCollectionMethods.type].distinct_eval(args(0).asInstanceOf[MethodCall],
+            args(1).asInstanceOf[Coll[Any]])(args(2).asInstanceOf[ErgoTreeEvaluator])
+        },
+        mkMethod(clazz, "startsWith_eval", Array[Class[_]](classOf[MethodCall], classOf[Coll[_]], classOf[Coll[_]], classOf[ErgoTreeEvaluator])) { (obj, args) =>
+          obj.asInstanceOf[SCollectionMethods.type].startsWith_eval(args(0).asInstanceOf[MethodCall],
+            args(1).asInstanceOf[Coll[Any]], args(2).asInstanceOf[Coll[Any]])(args(3).asInstanceOf[ErgoTreeEvaluator])
+        },
+        mkMethod(clazz, "endsWith_eval", Array[Class[_]](classOf[MethodCall], classOf[Coll[_]], classOf[Coll[_]], classOf[ErgoTreeEvaluator])) { (obj, args) =>
+          obj.asInstanceOf[SCollectionMethods.type].endsWith_eval(args(0).asInstanceOf[MethodCall],
+            args(1).asInstanceOf[Coll[Any]], args(2).asInstanceOf[Coll[Any]])(args(3).asInstanceOf[ErgoTreeEvaluator])
         }
       )
     )

data/shared/src/main/scala/sigma/ast/methods.scala

@@ -1020,7 +1020,7 @@ object SCollectionMethods extends MethodsContainer with MethodByNameUnapply {
     SFunc(Array(ThisType, tIV, SInt), SInt, paramIVSeq),
       26, PerItemCost(baseCost = JitCost(20), perChunkCost = JitCost(10), chunkSize = 2))
       .withIRInfo(MethodCallIrBuilder, javaMethodOf[Coll[_], Any, Int]("indexOf"))
-      .withInfo(MethodCall, "")
+      .withInfo(MethodCall, "Returns index of a collection element, or -1 if not found")
 
   /** Implements evaluation of Coll.indexOf method call ErgoTree node.
     * Called via reflection based on naming convention.
@@ -1052,8 +1052,7 @@ object SCollectionMethods extends MethodsContainer with MethodByNameUnapply {
     baseCost = JitCost(10), perChunkCost = JitCost(1), chunkSize = 10)
 
   val ZipMethod = SMethod(this, "zip",
-    SFunc(Array(ThisType, tOVColl), SCollection(STuple(tIV, tOV)), Array[STypeParam](tIV, tOV)),
-    29, Zip_CostKind)
+    SFunc(Array(ThisType, tOVColl), SCollection(STuple(tIV, tOV)), Array[STypeParam](tIV, tOV)), 29, Zip_CostKind)
       .withIRInfo(MethodCallIrBuilder)
       .withInfo(MethodCall, "")
 
@@ -1069,29 +1068,133 @@ object SCollectionMethods extends MethodsContainer with MethodByNameUnapply {
     }
   }
 
+  // ======== 6.0 methods below ===========
+
+  private val reverseCostKind = Append.costKind
+
+  val ReverseMethod = SMethod(this, "reverse",
+    SFunc(Array(ThisType), ThisType, paramIVSeq), 30, reverseCostKind)
+    .withIRInfo(MethodCallIrBuilder)
+    .withInfo(MethodCall, "")
+
+  /** Implements evaluation of Coll.reverse method call ErgoTree node.
+    * Called via reflection based on naming convention.
+    * @see SMethod.evalMethod
+    */
+  def reverse_eval[A](mc: MethodCall, xs: Coll[A])
+                    (implicit E: ErgoTreeEvaluator): Coll[A] = {
+    val m = mc.method
+    E.addSeqCost(m.costKind.asInstanceOf[PerItemCost], xs.length, m.opDesc) { () =>
+      xs.reverse
+    }
+  }
+
+  private val distinctCostKind = PerItemCost(baseCost = JitCost(60), perChunkCost = JitCost(5), chunkSize = 100)
+
+  val DistinctMethod = SMethod(this, "distinct",
+    SFunc(Array(ThisType), ThisType, paramIVSeq), 31, distinctCostKind)
+    .withIRInfo(MethodCallIrBuilder)
+    .withInfo(MethodCall, "Returns inversed collection.")
+
+  /** Implements evaluation of Coll.reverse method call ErgoTree node.
+    * Called via reflection based on naming convention.
+    * @see SMethod.evalMethod
+    */
+  def distinct_eval[A](mc: MethodCall, xs: Coll[A])
+                     (implicit E: ErgoTreeEvaluator): Coll[A] = {
+    val m = mc.method
+    E.addSeqCost(m.costKind.asInstanceOf[PerItemCost], xs.length, m.opDesc) { () =>
+      xs.distinct
+    }
+  }
+
+  private val startsWithCostKind = Zip_CostKind
+
+  val StartsWithMethod = SMethod(this, "startsWith",
+    SFunc(Array(ThisType, ThisType), SBoolean, paramIVSeq), 32, startsWithCostKind)
+    .withIRInfo(MethodCallIrBuilder)
+    .withInfo(MethodCall, "Returns true if this collection starts with given one, false otherwise.",
+      ArgInfo("prefix", "Collection to be checked for being a prefix of this collection."))
+
+  /** Implements evaluation of Coll.zip method call ErgoTree node.
+    * Called via reflection based on naming convention.
+    * @see SMethod.evalMethod
+    */
+  def startsWith_eval[A](mc: MethodCall, xs: Coll[A], ys: Coll[A])
+                    (implicit E: ErgoTreeEvaluator): Boolean = {
+    val m = mc.method
+    E.addSeqCost(m.costKind.asInstanceOf[PerItemCost], xs.length, m.opDesc) { () =>
+      xs.startsWith(ys)
+    }
+  }
+
+  private val endsWithCostKind = Zip_CostKind
+
+  val EndsWithMethod = SMethod(this, "endsWith",
+    SFunc(Array(ThisType, ThisType), SBoolean, paramIVSeq), 33, endsWithCostKind)
+    .withIRInfo(MethodCallIrBuilder)
+    .withInfo(MethodCall, "Returns true if this collection ends with given one, false otherwise.",
+      ArgInfo("suffix", "Collection to be checked for being a suffix of this collection."))
+
+  /** Implements evaluation of Coll.zip method call ErgoTree node.
+    * Called via reflection based on naming convention.
+    * @see SMethod.evalMethod
+    */
+  def endsWith_eval[A](mc: MethodCall, xs: Coll[A], ys: Coll[A])
+                        (implicit E: ErgoTreeEvaluator): Boolean = {
+    val m = mc.method
+    E.addSeqCost(m.costKind.asInstanceOf[PerItemCost], xs.length, m.opDesc) { () =>
+      xs.endsWith(ys)
+    }
+  }
+
+  val GetMethod = SMethod(this, "get",
+    SFunc(Array(ThisType, SInt), SOption(tIV), Array[STypeParam](tIV)), 34, ByIndex.costKind)
+    .withIRInfo(MethodCallIrBuilder)
+    .withInfo(MethodCall,
+              "Returns Some(element) if there is an element at given index, None otherwise.",
+              ArgInfo("index", "Index of an element (starting from 0).")
+            )
+
+  private val v5Methods = super.getMethods() ++ Seq(
+    SizeMethod,
+    GetOrElseMethod,
+    MapMethod,
+    ExistsMethod,
+    FoldMethod,
+    ForallMethod,
+    SliceMethod,
+    FilterMethod,
+    AppendMethod,
+    ApplyMethod,
+    IndicesMethod,
+    FlatMapMethod,
+    PatchMethod,
+    UpdatedMethod,
+    UpdateManyMethod,
+    IndexOfMethod,
+    ZipMethod
+  )
+
+  private val v6Methods = v5Methods ++ Seq(
+    ReverseMethod,
+    DistinctMethod,
+    StartsWithMethod,
+    EndsWithMethod,
+    GetMethod
+  )
+
   /** This method should be overriden in derived classes to add new methods in addition to inherited.
     * Typical override: `super.getMethods() ++ Seq(m1, m2, m3)`
     */
-  override protected def getMethods(): Seq[SMethod] = super.getMethods() ++
-      Seq(
-        SizeMethod,
-        GetOrElseMethod,
-        MapMethod,
-        ExistsMethod,
-        FoldMethod,
-        ForallMethod,
-        SliceMethod,
-        FilterMethod,
-        AppendMethod,
-        ApplyMethod,
-        IndicesMethod,
-        FlatMapMethod,
-        PatchMethod,
-        UpdatedMethod,
-        UpdateManyMethod,
-        IndexOfMethod,
-        ZipMethod
-      )
+  override protected def getMethods(): Seq[SMethod] = {
+    if (VersionContext.current.isV6SoftForkActivated) {
+      v6Methods
+    } else {
+      v5Methods
+    }
+  }
+
 }
 
 object STupleMethods extends MethodsContainer {

sc/shared/src/main/scala/sigma/compiler/ir/GraphBuilding.scala

@@ -987,6 +987,19 @@ trait GraphBuilding extends Base with DefRewriting { IR: IRContext =>
               val i = asRep[Int](argsV(0))
               val d = asRep[t](argsV(1))
               xs.getOrElse(i, d)
+            case SCollectionMethods.ReverseMethod.name =>
+              xs.reverse
+            case SCollectionMethods.DistinctMethod.name =>
+              xs.distinct
+            case SCollectionMethods.StartsWithMethod.name =>
+              val ys = asRep[Coll[t]](argsV(0))
+              xs.startsWith(ys)
+            case SCollectionMethods.EndsWithMethod.name =>
+              val ys = asRep[Coll[t]](argsV(0))
+              xs.endsWith(ys)
+            case SCollectionMethods.GetMethod.name =>
+              val idx = asRep[Int](argsV(0))
+              xs.get(idx)
             case _ => throwError()
           }
           case (opt: ROption[t]@unchecked, SOptionMethods) => method.name match {

sc/shared/src/main/scala/sigma/compiler/ir/GraphIRReflection.scala

@@ -203,6 +203,22 @@ object GraphIRReflection {
         },
         mkMethod(clazz, "exists", Array[Class[_]](classOf[Base#Ref[_]])) { (obj, args) =>
           obj.asInstanceOf[ctx.Coll[Any]].exists(args(0).asInstanceOf[ctx.Ref[Any => Boolean]])
+        },
+        // V6 methods
+        mkMethod(clazz, "reverse", Array[Class[_]]()) { (obj, _) =>
+          obj.asInstanceOf[ctx.Coll[Any]].reverse
+        },
+        mkMethod(clazz, "distinct", Array[Class[_]]()) { (obj, _) =>
+          obj.asInstanceOf[ctx.Coll[Any]].distinct
+        },
+        mkMethod(clazz, "startsWith", Array[Class[_]](classOf[Base#Ref[_]])) { (obj, args) =>
+          obj.asInstanceOf[ctx.Coll[Any]].startsWith(args(0).asInstanceOf[ctx.Ref[ctx.Coll[Any]]])
+        },
+        mkMethod(clazz, "endsWith", Array[Class[_]](classOf[Base#Ref[_]])) { (obj, args) =>
+          obj.asInstanceOf[ctx.Coll[Any]].endsWith(args(0).asInstanceOf[ctx.Ref[ctx.Coll[Any]]])
+        },
+        mkMethod(clazz, "get", Array[Class[_]](classOf[Base#Ref[_]])) { (obj, args) =>
+          obj.asInstanceOf[ctx.Coll[_]].apply(args(0).asInstanceOf[ctx.Ref[Int]])
         }
       )
     )

sc/shared/src/main/scala/sigma/compiler/ir/wrappers/sigma/CollsUnit.scala

@@ -14,6 +14,7 @@ import sigma.compiler.ir.{Base, IRContext}
       implicit def eA: Elem[A];
       def length: Ref[Int];
       def apply(i: Ref[Int]): Ref[A];
+      def get(index: Ref[Int]): Ref[WOption[A]];
       def getOrElse(index: Ref[Int], default: Ref[A]): Ref[A];
       def map[B](f: Ref[scala.Function1[A, B]]): Ref[Coll[B]];
       def zip[B](ys: Ref[Coll[B]]): Ref[Coll[scala.Tuple2[A, B]]];
@@ -29,6 +30,10 @@ import sigma.compiler.ir.{Base, IRContext}
       def updateMany(indexes: Ref[Coll[Int]], values: Ref[Coll[A]]): Ref[Coll[A]];
       def slice(from: Ref[Int], until: Ref[Int]): Ref[Coll[A]];
       def append(other: Ref[Coll[A]]): Ref[Coll[A]];
+      def reverse: Ref[Coll[A]]
+      def distinct: Ref[Coll[A]]
+      def startsWith(ys: Ref[Coll[A]]): Ref[Boolean];
+      def endsWith(ys: Ref[Coll[A]]): Ref[Boolean];
     };
     trait CollBuilder extends Def[CollBuilder] {
       def fromItems[T](items: Ref[T]*)(implicit cT: Elem[T]): Ref[Coll[T]];