close #906: lazy evaluation of default in Option.getOrElse and Coll.g…

…etOrElse
ergoplatform · Jun 11, 2024 · aaef77e · aaef77e
1 parent dd62bd7
commit aaef77e
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Showing 2 changed files with 36 additions and 17 deletions.
diff --git a/data/shared/src/main/scala/sigma/ast/transformers.scala b/data/shared/src/main/scala/sigma/ast/transformers.scala
@@ -10,7 +10,7 @@ import sigma.eval.ErgoTreeEvaluator.DataEnv
 import sigma.serialization.CoreByteWriter.ArgInfo
 import sigma.serialization.OpCodes
 import sigma.serialization.ValueCodes.OpCode
-import sigma.{Box, Coll, Evaluation}
+import sigma.{Box, Coll, Evaluation, VersionContext}
 
 // TODO refactor: remove this trait as it doesn't have semantic meaning
 
@@ -258,10 +258,22 @@ case class ByIndex[V <: SType](input: Value[SCollection[V]],
     val indexV = index.evalTo[Int](env)
     default match {
       case Some(d) =>
-        val dV = d.evalTo[V#WrappedType](env)
-        Value.checkType(d, dV) // necessary because cast to V#WrappedType is erased
-        addCost(ByIndex.costKind)
-        inputV.getOrElse(indexV, dV)
+        if (VersionContext.current.isV6SoftForkActivated) {
+          // lazy evaluation of default in 6.0
+          addCost(ByIndex.costKind)
+          if (inputV.isDefinedAt(indexV)) {
+            inputV.apply(indexV)
+          } else {
+            val dV = d.evalTo[V#WrappedType](env)
+            Value.checkType(d, dV) // necessary because cast to V#WrappedType is erased
+            inputV.getOrElse(indexV, dV)
+          }
+        } else {
+          val dV = d.evalTo[V#WrappedType](env)
+          Value.checkType(d, dV) // necessary because cast to V#WrappedType is erased
+          addCost(ByIndex.costKind)
+          inputV.getOrElse(indexV, dV)
+        }
       case _ =>
         addCost(ByIndex.costKind)
         inputV.apply(indexV)
@@ -613,11 +625,22 @@ case class OptionGetOrElse[V <: SType](input: Value[SOption[V]], default: Value[
   override val opType = SFunc(IndexedSeq(input.tpe, tpe), tpe)
   override def tpe: V = input.tpe.elemType
   protected final override def eval(env: DataEnv)(implicit E: ErgoTreeEvaluator): Any = {
-    val inputV = input.evalTo[Option[V#WrappedType]](env)
-    val dV = default.evalTo[V#WrappedType](env)  // TODO v6.0: execute lazily (see https://github.com/ScorexFoundation/sigmastate-interpreter/issues/906)
-    Value.checkType(default, dV) // necessary because cast to V#WrappedType is erased
-    addCost(OptionGetOrElse.costKind)
-    inputV.getOrElse(dV)
+    if(VersionContext.current.isV6SoftForkActivated) {
+      // lazy evaluation of default in 6.0
+      val inputV = input.evalTo[Option[V#WrappedType]](env)
+      addCost(OptionGetOrElse.costKind)
+      inputV.getOrElse {
+        val dV = default.evalTo[V#WrappedType](env)
+        Value.checkType(default, dV) // necessary because cast to V#WrappedType is erased
+        dV
+      }
+    } else {
+      val inputV = input.evalTo[Option[V#WrappedType]](env)
+      val dV = default.evalTo[V#WrappedType](env)
+      Value.checkType(default, dV) // necessary because cast to V#WrappedType is erased
+      addCost(OptionGetOrElse.costKind)
+      inputV.getOrElse(dV)
+    }
   }
 }
 object OptionGetOrElse extends ValueCompanion with FixedCostValueCompanion {

diff --git a/sc/shared/src/test/scala/sigmastate/utxo/BasicOpsSpecification.scala b/sc/shared/src/test/scala/sigmastate/utxo/BasicOpsSpecification.scala
@@ -166,7 +166,6 @@ class BasicOpsSpecification extends CompilerTestingCommons
       """{
         |  getVar[Int](1).getOrElse(getVar[Int](44).get) > 0
         |}
-        |
         |""".stripMargin,
       null
     )
@@ -179,15 +178,12 @@ class BasicOpsSpecification extends CompilerTestingCommons
   }
 
   property("Lazy evaluation of default in Coll.getOrElse") {
-    val customExt = Map (
-      1.toByte -> IntConstant(5)
-    ).toSeq
-    def optTest() = test("getOrElse", env, customExt,
+    def optTest() = test("getOrElse", env, ext,
       """{
         |  val c = Coll[Int](1)
-        |  c.getOrElse(0, getVar[Int](44).get) > 0
+        |  c.getOrElse(0, getVar[Int](44).get) > 0 &&
+        |   c.getOrElse(1, c.getOrElse(0, getVar[Int](44).get)) > 0
         |}
-        |
         |""".stripMargin,
       null
     )