Topology refactoring (#100)

* Topology refactoring

* TransformSpec fixed & improved

* Fixes #98

* Better Par handling

* Introduced Cursor class

* Better exit process for par branch

* Force move to target peer when exiting from a par branch

aqua-src/error.aqua

@@ -13,6 +13,8 @@ service Test("test"):
     getUserList: -> []User
     doSomething: -> bool
     check: bool -> ()
+    log: string -> ()
+    getString: string -> string
 
 func initAfterJoin(me: User) -> []User:
     allUsers <- Test.getUserList()
@@ -41,4 +43,19 @@ func checkStreams(ch: []string) -> []bool:
         on b:
             stream <- Peer.is_connected(b)
     handleArr(stream)
-    <- stream
+    <- stream
+
+func test(user: string, relay_id: string) -> string:
+    on relay_id:
+        Peer.is_connected("on relay_id")
+    on user:
+        Peer.is_connected("on user")
+    par Peer.is_connected("par on init peer")
+    <- ""
+
+-- should fail, as using str2 in parallel
+func topologyTest(friend: string, friendRelay: string) -> string:
+    on friend via friendRelay:
+        str2 <- Test.getString("friends string via")
+    par Test.log(str2)
+    <- "finish"

backend/ts/src/main/scala/aqua/backend/ts/TypescriptFile.scala

@@ -14,15 +14,18 @@ case class TypescriptFile(script: ScriptModel) {
 object TypescriptFile {
 
   val Header: String =
-    """/**
+    s"""/**
-      | *
+       | *
-      | * This file is auto-generated. Do not edit manually: changes may be erased.
+       | * This file is auto-generated. Do not edit manually: changes may be erased.
-      | * Generated by Aqua compiler: https://github.com/fluencelabs/aqua/. 
+       | * Generated by Aqua compiler: https://github.com/fluencelabs/aqua/. 
-      | * If you find any bugs, please write an issue on GitHub: https://github.com/fluencelabs/aqua/issues
+       | * If you find any bugs, please write an issue on GitHub: https://github.com/fluencelabs/aqua/issues
-      | *
+       | * Aqua version: ${Option(getClass.getPackage.getImplementationVersion)
-      | */
+      .filter(_.nonEmpty)
-      |import { FluenceClient, PeerIdB58 } from '@fluencelabs/fluence';
+      .getOrElse("Unknown")}
-      |import { RequestFlowBuilder } from '@fluencelabs/fluence/dist/api.unstable';
+       | *
-      |""".stripMargin
+       | */
+       |import { FluenceClient, PeerIdB58 } from '@fluencelabs/fluence';
+       |import { RequestFlowBuilder } from '@fluencelabs/fluence/dist/api.unstable';
+       |""".stripMargin
 
 }

build.sbt

@@ -1,18 +1,18 @@
 val dottyVersion = "2.13.5"
 
+//val dottyVersion = "3.0.0-RC3"
+
 scalaVersion := dottyVersion
 
-//val dottyVersion = "3.0.0-RC2"
-
 val baseAquaVersion = settingKey[String]("base aqua version")
 
-val catsV = "2.5.0"
+val catsV = "2.6.0"
 val catsParseV = "0.3.2"
-val monocleV = "3.0.0-M4"
+val monocleV = "3.0.0-M5"
-val scalaTestV = "3.2.7"
+val scalaTestV = "3.2.7" // TODO update version for scala 3-RC3
-val fs2V = "3.0.0"
+val fs2V = "3.0.2"
-val catsEffectV = "3.0.2"
+val catsEffectV = "3.1.0"
-val declineV = "2.0.0-RC1"
+val declineV = "2.0.0-RC1" // Scala3 issue: https://github.com/bkirwi/decline/issues/260
 
 name := "aqua-hll"
 

model/src/main/scala/aqua/model/Model.scala

@@ -17,6 +17,7 @@ object Model {
       case (l: ScriptModel, r: ScriptModel) =>
         ScriptModel.SMMonoid.combine(l, r)
 
+      case (l: EmptyModel, r: EmptyModel) => EmptyModel(l.log + " |+| " + r.log)
       case (_: EmptyModel, r) => r
       case (l, _: EmptyModel) => l
 
@@ -24,6 +25,7 @@ object Model {
         ScriptModel.toScriptPart(l).fold(r)(ScriptModel.SMMonoid.combine(_, r))
       case (l: ScriptModel, r) =>
         ScriptModel.toScriptPart(r).fold(l)(ScriptModel.SMMonoid.combine(l, _))
+
       case (l, r) =>
         ScriptModel
           .toScriptPart(l)
@@ -31,8 +33,6 @@ object Model {
             ScriptModel.toScriptPart(r).fold(l)(rs => ScriptModel.SMMonoid.combine(ls, rs))
           )
 
-      case (l: EmptyModel, r: EmptyModel) => EmptyModel(l.log + " |+| " + r.log)
-
     }
   }
 }

model/src/main/scala/aqua/model/ValueModel.scala

@@ -1,12 +1,20 @@
 package aqua.model
 
 import aqua.types.Type
+import cats.Eq
 import cats.data.Chain
 
 sealed trait ValueModel {
   def resolveWith(map: Map[String, ValueModel]): ValueModel = this
 }
 
+object ValueModel {
+
+  implicit object ValueModelEq extends Eq[ValueModel] {
+    override def eqv(x: ValueModel, y: ValueModel): Boolean = x == y
+  }
+}
+
 case class LiteralModel(value: String) extends ValueModel
 
 object LiteralModel {

model/src/main/scala/aqua/model/func/body/OpTag.scala

@@ -27,15 +27,19 @@ sealed trait OpTag {
   }
 
 }
+sealed trait GroupTag extends OpTag
+sealed trait SeqGroupTag extends GroupTag
 
-case object SeqTag extends OpTag
+case object SeqTag extends SeqGroupTag
-case object ParTag extends OpTag
+case object ParTag extends GroupTag
-case object XorTag extends OpTag
+case object XorTag extends GroupTag
 case class XorParTag(xor: FuncOp, par: FuncOp) extends OpTag
-case class OnTag(peerId: ValueModel, via: Chain[ValueModel]) extends OpTag
+case class OnTag(peerId: ValueModel, via: Chain[ValueModel]) extends SeqGroupTag
 case class NextTag(item: String) extends OpTag
-case class MatchMismatchTag(left: ValueModel, right: ValueModel, shouldMatch: Boolean) extends OpTag
+
-case class ForTag(item: String, iterable: ValueModel) extends OpTag
+case class MatchMismatchTag(left: ValueModel, right: ValueModel, shouldMatch: Boolean)
+    extends SeqGroupTag
+case class ForTag(item: String, iterable: ValueModel) extends SeqGroupTag
 
 case class CallArrowTag(
   funcName: String,

model/src/main/scala/aqua/model/topology/ChainZipper.scala

@@ -0,0 +1,51 @@
+package aqua.model.topology
+
+import cats.data.Chain
+import cats.free.Cofree
+
+case class ChainZipper[T](prev: Chain[T], current: T, next: Chain[T]) {
+
+  def chain: Chain[T] = (prev :+ current) ++ next
+
+  def moveLeft: Option[ChainZipper[T]] =
+    prev.initLast.map { case (init, last) =>
+      ChainZipper(init, last, current +: next)
+    }
+
+  def moveRight: Option[ChainZipper[T]] =
+    next.uncons.map { case (head, tail) =>
+      ChainZipper(prev :+ current, head, tail)
+    }
+
+  def replaceInjecting(cz: ChainZipper[T]): ChainZipper[T] =
+    copy(prev ++ cz.prev, cz.current, cz.next ++ next)
+}
+
+object ChainZipper {
+  def one[T](el: T): ChainZipper[T] = ChainZipper(Chain.empty, el, Chain.empty)
+
+  def fromChain[T](chain: Chain[T], prev: Chain[T] = Chain.empty): Chain[ChainZipper[T]] =
+    chain.uncons.fold(Chain.empty[ChainZipper[T]]) { case (t, next) =>
+      ChainZipper(prev, t, next) +: fromChain(next, prev :+ t)
+    }
+
+  def fromChainMap[T](chain: Chain[T], prev: Chain[T] = Chain.empty)(
+    f: ChainZipper[T] => Option[T]
+  ): Chain[T] =
+    chain.uncons.fold(Chain.empty[T]) { case (t, next) =>
+      f(ChainZipper(prev, t, next)).fold(fromChainMap(next, prev)(f))(r =>
+        r +: fromChainMap(next, prev :+ r)(f)
+      )
+    }
+
+  object Matchers {
+
+    object `current` {
+      def unapply[T](cz: ChainZipper[T]): Option[T] = Some(cz.current)
+    }
+
+    object `head` {
+      def unapply[F[_], T](cz: ChainZipper[Cofree[F, T]]): Option[T] = Some(cz.current.head)
+    }
+  }
+}

model/src/main/scala/aqua/model/topology/Cursor.scala

@@ -0,0 +1,81 @@
+package aqua.model.topology
+
+import Topology.Tree
+import aqua.model.func.body.{OnTag, OpTag, ParTag, SeqTag}
+import cats.Eval
+import cats.data.Chain
+import cats.free.Cofree
+
+case class Cursor(point: ChainZipper[Tree], loc: Location) {
+
+  def downLoc(tree: Tree): Location =
+    loc.down(point.copy(current = tree))
+
+  def prevOnTags: Chain[OnTag] =
+    Chain
+      .fromSeq(
+        point.prev.lastOption
+          .orElse(loc.lastLeftSeq.map(_._1.current))
+          .toList
+          .flatMap(Cursor.rightBoundary)
+          .takeWhile {
+            case ParTag => false
+            case _ => true
+          }
+      )
+      .collect { case o: OnTag =>
+        o
+      }
+
+  def nextOnTags: Chain[OnTag] =
+    Chain
+      .fromSeq(
+        loc.lastRightSeq
+          .map(_._1.current)
+          .toList
+          .flatMap(Cursor.leftBoundary)
+          .takeWhile {
+            case ParTag => false
+            case _ => true
+          }
+      )
+      .collect { case o: OnTag =>
+        o
+      }
+}
+
+object Cursor {
+
+  def rightBoundary(root: Tree): LazyList[OpTag] =
+    root.head #:: LazyList.unfold(root.tail)(_.value.lastOption.map(lo => lo.head -> lo.tail))
+
+  def leftBoundary(root: Tree): LazyList[OpTag] =
+    root.head #:: LazyList.unfold(root.tail)(_.value.headOption.map(lo => lo.head -> lo.tail))
+
+  def transform(root: Tree)(f: Cursor => List[Tree]): Option[Tree] = {
+    def step(cursor: Cursor): Option[Tree] =
+      f(cursor) match {
+        case Nil => None
+        case h :: Nil =>
+          val np = cursor.downLoc(h)
+          Some(h.copy(tail = h.tail.map(ChainZipper.fromChainMap(_)(cz => step(Cursor(cz, np))))))
+        case hs =>
+          ChainZipper
+            .fromChain(Chain.fromSeq(hs))
+            .map(cursor.point.replaceInjecting)
+            .map { cfh =>
+              val np = cursor.loc.down(cfh)
+              cfh.current.copy(tail =
+                cfh.current.tail.map(ChainZipper.fromChainMap(_)(cz => step(Cursor(cz, np))))
+              )
+            }
+            .uncons
+            .map {
+              case (h, t) if t.isEmpty => h
+              case (h, t) => Cofree(SeqTag, Eval.later(h +: t))
+            }
+      }
+    step(Cursor(ChainZipper.one(root), Location()))
+  }
+
+}

model/src/main/scala/aqua/model/topology/Location.scala

@@ -0,0 +1,63 @@
+package aqua.model.topology
+
+import aqua.model.ValueModel
+import aqua.model.func.body.{OnTag, SeqGroupTag}
+import cats.data.Chain
+import cats.free.Cofree
+
+case class Location(path: List[ChainZipper[Topology.Tree]] = Nil) {
+  def down(h: ChainZipper[Topology.Tree]): Location = copy(h :: path)
+
+  def lastOn: Option[OnTag] = path.map(_.current.head).collectFirst { case o: OnTag =>
+    o
+  }
+
+  def pathOn: List[OnTag] = path.map(_.current.head).collect { case o: OnTag =>
+    o
+  }
+
+  def pathViaChain: Chain[ValueModel] = Chain.fromSeq(
+    path
+      .map(_.current.head)
+      .collectFirst { case t: OnTag =>
+        t.via.toList
+      }
+      .toList
+      .flatten
+  )
+
+  def lastLeftSeq: Option[(ChainZipper[Topology.Tree], Location)] =
+    path match {
+      case (cz @ ChainZipper(prev, Cofree(_: SeqGroupTag, _), _)) :: tail if prev.nonEmpty =>
+        cz.moveLeft.map(_ -> Location(tail))
+      case _ :: tail => Location(tail).lastLeftSeq
+      case Nil => None
+    }
+
+  def lastRightSeq: Option[(ChainZipper[Topology.Tree], Location)] =
+    path match {
+      case (cz @ ChainZipper(_, Cofree(_: SeqGroupTag, _), next)) :: tail if next.nonEmpty =>
+        cz.moveRight.map(_ -> Location(tail))
+      case _ :: tail => Location(tail).lastRightSeq
+      case Nil => None
+    }
+
+  path.collectFirst {
+    case ChainZipper(prev, Cofree(_: SeqGroupTag, _), _) if prev.nonEmpty => prev.lastOption
+  }.flatten
+}
+
+object Location {
+
+  object Matchers {
+
+    object /: {
+
+      def unapply(loc: Location): Option[(ChainZipper[Topology.Tree], Location)] =
+        loc.path match {
+          case h :: tail => Some(h -> Location(tail))
+          case _ => None
+        }
+    }
+  }
+}

model/src/main/scala/aqua/model/topology/Topology.scala

@@ -0,0 +1,96 @@
+package aqua.model.topology
+
+import aqua.model.ValueModel
+import aqua.model.func.body._
+import cats.Eval
+import cats.data.Chain
+import cats.free.Cofree
+import ChainZipper.Matchers._
+import Location.Matchers._
+
+object Topology {
+  type Tree = Cofree[Chain, OpTag]
+
+  // Walks through peer IDs, doing a noop function on each
+  // If same IDs are found in a row, does noop only once
+  // if there's a chain like a -> b -> c -> ... -> b -> g, remove everything between b and b
+  def through(peerIds: Chain[ValueModel]): Chain[Tree] =
+    peerIds
+      .foldLeft(Chain.empty[ValueModel]) {
+        case (acc, p) if acc.lastOption.contains(p) => acc
+        case (acc, p) if acc.contains(p) => acc.takeWhile(_ != p) :+ p
+        case (acc, p) => acc :+ p
+      }
+      .map(FuncOps.noop)
+      .map(_.tree)
+
+  def mapTag(tag: OpTag, loc: Location): OpTag = tag match {
+    case c: CallServiceTag if c.peerId.isEmpty =>
+      c.copy(peerId = loc.lastOn.map(_.peerId))
+    case t => t
+  }
+
+  def resolve(op: Tree): Tree =
+    Cofree
+      .cata[Chain, OpTag, Tree](resolveOnMoves(op)) {
+        case (SeqTag | _: OnTag, children) =>
+          Eval.later(
+            Cofree(
+              SeqTag,
+              Eval.now(children.flatMap {
+                case Cofree(SeqTag, ch) => ch.value
+                case cf => Chain.one(cf)
+              })
+            )
+          )
+        case (head, children) => Eval.later(Cofree(head, Eval.now(children)))
+      }
+      .value
+
+  def resolveOnMoves(op: Tree): Tree =
+    Cursor
+      .transform(op) {
+        case c @ Cursor(
+              cz @ `current`(cf),
+              loc @ `head`(parent: GroupTag) /: _
+            ) =>
+          val cfu = cf.copy(mapTag(cf.head, loc))
+
+          val getThere = (cfu.head, loc.pathOn) match {
+            case (OnTag(pid, _), h :: _) if h.peerId == pid => Chain.empty[ValueModel]
+            case (OnTag(_, via), h :: _) =>
+              h.via.reverse ++ via
+            case (_, _) => Chain.empty[ValueModel]
+          }
+
+          val prevOn = c.prevOnTags
+
+          val prevPath = prevOn.map { case OnTag(_, v) =>
+            v.reverse
+          }
+            .flatMap(identity)
+
+          val nextOn = parent match {
+            case ParTag | XorTag => c.nextOnTags
+            case _ => Chain.empty[OnTag]
+          }
+          val nextPath = (if (nextOn.nonEmpty) getThere.reverse else Chain.empty) ++ nextOn.map {
+            case OnTag(_, v) =>
+              v.reverse
+          }
+            .flatMap(identity) ++ Chain.fromOption(
+            // Dirty fix for join behaviour
+            nextOn.lastOption.filter(_ => parent == ParTag).map(_.peerId)
+          )
+
+          if (prevOn.isEmpty && getThere.isEmpty) cfu :: Nil
+          else
+            (through(prevPath ++ loc.pathViaChain ++ getThere)
+              .append(cfu) ++ through(nextPath)).toList
+
+        case Cursor(ChainZipper(_, cf, _), loc) =>
+          cf.copy(mapTag(cf.head, loc)) :: Nil
+      }
+      .getOrElse(op)
+
+}

model/src/main/scala/aqua/model/transform/Topology.scala

@@ -1,106 +0,0 @@
-package aqua.model.transform
-
-import aqua.model.ValueModel
-import aqua.model.func.body.{CallServiceTag, FuncOps, OnTag, OpTag, ParTag, SeqTag}
-import cats.Eval
-import cats.data.Chain
-import cats.free.Cofree
-
-object Topology {
-  type Tree = Cofree[Chain, OpTag]
-
-  def rightBoundary(root: Tree): List[OpTag] =
-    root.head :: root.tailForced.lastOption.fold(List.empty[OpTag])(rightBoundary)
-
-  // Walks through peer IDs, doing a noop function on each
-  // If same IDs are found in a row, does noop only once
-  // TODO: if there's a chain like a -> b -> c -> ... -> b -> g, remove everything between b and b
-  def through(peerIds: Chain[ValueModel]): Chain[Tree] =
-    peerIds
-      .foldLeft(Chain.empty[ValueModel]) {
-        case (acc, p) if acc.lastOption.contains(p) => acc
-        case (acc, p) => acc :+ p
-      }
-      .map(FuncOps.noop)
-      .map(_.tree)
-
-  // TODO: after topology is resolved, OnTag should be eliminated
-  def resolve(op: Tree): Tree =
-    transformWithPath(op) {
-      case (path, c: CallServiceTag, children) if c.peerId.isEmpty =>
-        Cofree[Chain, OpTag](
-          c.copy(peerId = path.collectFirst { case OnTag(peerId, _) =>
-            peerId
-          }),
-          children
-        )
-      case (path, tag @ OnTag(pid, via), children) =>
-        // Drop seq/par/xor from path
-        val pathOn = path.collect { case ot: OnTag =>
-          ot
-        }
-
-        pathOn match {
-          // If we are on the right node, do nothing
-          case Nil =>
-            Cofree[Chain, OpTag](tag, children)
-          case h :: _ if h.peerId == pid =>
-            Cofree[Chain, OpTag](tag, children)
-          case h :: _ =>
-            Cofree[Chain, OpTag](
-              tag,
-              // TODO: merge children, if possible
-              children.map(through(h.via.reverse ++ via) ++ _)
-            )
-        }
-
-      case (path, SeqTag, children) =>
-        // TODO if we have OnTag, and then something else, need to get back
-        // AND keep in mind that we will handle all the children with OnTag processor!
-
-        val pathViaChain = Chain.fromSeq(path.collectFirst { case t: OnTag =>
-          t.via.toList
-        }.toList.flatten)
-
-        def modifyChildrenList(list: List[Tree], prev: Option[Tree]): Chain[Tree] = list match {
-          case Nil => Chain.empty
-          case op :: tail =>
-            // TODO further improve
-            val prevPath = Chain
-              .fromSeq(prev.toList.flatMap(rightBoundary).takeWhile {
-                case ParTag => false
-                case _ => true
-              })
-              .collect { case OnTag(_, v) =>
-                v.reverse
-              }
-
-            if (prevPath.isEmpty) op +: modifyChildrenList(tail, Some(op))
-            else
-              through(prevPath.flatMap(identity) ++ pathViaChain).append(op) ++ modifyChildrenList(
-                tail,
-                Some(op)
-              )
-
-          case o :: ops => o +: modifyChildrenList(ops, Some(o))
-        }
-
-        Cofree[Chain, OpTag](
-          SeqTag,
-          children.map(_.toList).map(modifyChildrenList(_, None))
-        )
-
-      case (_, t, children) =>
-        Cofree[Chain, OpTag](t, children)
-    }
-
-  def transformWithPath(cf: Tree, path: List[OpTag] = Nil)(
-    f: (List[OpTag], OpTag, Eval[Chain[Tree]]) => Tree
-  ): Tree = {
-    val newCf = f(path, cf.head, cf.tail)
-    Cofree[Chain, OpTag](
-      newCf.head,
-      newCf.tail.map(_.map(transformWithPath(_, newCf.head :: path)(f)))
-    )
-  }
-}

model/src/main/scala/aqua/model/transform/Transform.scala

@@ -3,6 +3,7 @@ package aqua.model.transform
 import aqua.model.func.body._
 import aqua.model.func.FuncCallable
 import aqua.model.VarModel
+import aqua.model.topology.Topology
 import aqua.types.ScalarType
 import cats.data.Chain
 import cats.free.Cofree

model/src/test/scala/aqua/model/topology/LocationSpec.scala

@@ -0,0 +1,23 @@
+package aqua.model.topology
+
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
+import Location.Matchers._
+import ChainZipper.Matchers._
+import aqua.model.func.body.SeqTag
+import cats.Eval
+import cats.data.Chain
+import cats.free.Cofree
+
+class LocationSpec extends AnyFlatSpec with Matchers {
+
+  "matchers" should "unapply correctly" in {
+    val loc =
+      Location(ChainZipper.one(Cofree(SeqTag, Eval.later(Chain.empty[Topology.Tree]))) :: Nil)
+
+    Option(loc).collect { case `head`(SeqTag) /: _ =>
+      true
+    } should be('defined)
+  }
+
+}

model/src/test/scala/aqua/model/topology/TopologySpec.scala

@@ -1,4 +1,4 @@
-package aqua.model.transform
+package aqua.model.topology
 
 import aqua.model.Node
 import org.scalatest.flatspec.AnyFlatSpec
@@ -20,14 +20,11 @@ class TopologySpec extends AnyFlatSpec with Matchers {
 
     val proc: Node = Topology.resolve(init)
 
-    val expected = on(
+    val expected =
-      initPeer,
-      relay :: Nil,
       seq(
         call(1, initPeer),
         call(2, initPeer)
       )
-    )
 
     proc should be(expected)
 
@@ -50,19 +47,8 @@ class TopologySpec extends AnyFlatSpec with Matchers {
 
     val proc: Node = Topology.resolve(init)
 
-    val expected = on(
+    val expected =
-      initPeer,
+      seq(through(relay), call(1, otherPeer), call(2, otherPeer))
-      relay :: Nil,
-      on(
-        otherPeer,
-        Nil,
-        through(relay),
-        seq(
-          call(1, otherPeer),
-          call(2, otherPeer)
-        )
-      )
-    )
 
     proc should be(expected)
   }
@@ -84,20 +70,13 @@ class TopologySpec extends AnyFlatSpec with Matchers {
 
     val proc: Node = Topology.resolve(init)
 
-    val expected = on(
+    val expected =
-      initPeer,
+      seq(
-      relay :: Nil,
-      on(
-        otherPeer,
-        otherRelay :: Nil,
         through(relay),
         through(otherRelay),
-        seq(
+        call(1, otherPeer),
-          call(1, otherPeer),
+        call(2, otherPeer)
-          call(2, otherPeer)
-        )
       )
-    )
 
     proc should be(expected)
   }
@@ -119,22 +98,15 @@ class TopologySpec extends AnyFlatSpec with Matchers {
 
     val proc: Node = Topology.resolve(init)
 
-    val expected = on(
+    val expected =
-      initPeer,
-      relay :: Nil,
       seq(
-        on(
+        through(relay),
-          otherPeer,
+        through(otherRelay),
-          otherRelay :: Nil,
+        call(1, otherPeer),
-          through(relay),
-          through(otherRelay),
-          call(1, otherPeer)
-        ),
         through(otherRelay),
         through(relay),
         call(2, initPeer)
       )
-    )
 
 //    println(Console.BLUE + init)
 //    println(Console.YELLOW + proc)
@@ -175,38 +147,25 @@ class TopologySpec extends AnyFlatSpec with Matchers {
 
     val proc: Node = Topology.resolve(init)
 
-    val expected = on(
+    val expected =
-      initPeer,
-      relay :: Nil,
       seq(
-        on(
+        through(relay),
+        through(otherRelay),
+        call(0, otherPeer),
+        through(otherRelay),
+        call(1, otherPeer2),
+        _match(
           otherPeer,
-          otherRelay :: Nil,
+          otherRelay,
-          through(relay),
+          seq(
-          through(otherRelay),
-          call(0, otherPeer),
-          on(
-            otherPeer2,
-            otherRelay :: Nil,
             through(otherRelay),
-            call(1, otherPeer2),
+            call(2, otherPeer)
-            _match(
-              otherPeer,
-              otherRelay,
-              on(
-                otherPeer,
-                otherRelay :: Nil,
-                through(otherRelay),
-                call(2, otherPeer)
-              )
-            )
           )
         ),
         through(otherRelay),
         through(relay),
         call(3, initPeer)
       )
-    )
 
 //    println(Console.BLUE + init)
 //    println(Console.YELLOW + proc)

model/src/test/scala/aqua/model/transform/TransformSpec.scala

@@ -32,17 +32,17 @@ class TransformSpec extends AnyFlatSpec with Matchers {
 
     val expectedFC =
       xor(
-        on(
+        seq(
-          initPeer,
+          dataCall(bc, "relay", initPeer),
-          relayV :: Nil,
+          through(relayV),
-          seq(
+          call(1, otherPeer),
-            dataCall(bc, "relay", initPeer),
+          through(relayV),
-            on(otherPeer, Nil, through(relayV), call(1, otherPeer)),
+          respCall(bc, ret, initPeer)
-            through(relayV),
-            on(initPeer, relayV :: Nil, respCall(bc, ret, initPeer))
-          )
         ),
-        on(initPeer, relayV :: Nil, xorErrorCall(bc, initPeer))
+        seq(
+          through(relayV),
+          xorErrorCall(bc, initPeer)
+        )
       )
 
     procFC.equalsOrPrintDiff(expectedFC) should be(true)
@@ -70,20 +70,18 @@ class TransformSpec extends AnyFlatSpec with Matchers {
 
     val expectedFC =
       xor(
-        on(
+        seq(
-          initPeer,
+          dataCall(bc, "relay", initPeer),
-          relayV :: Nil,
+          call(0, initPeer),
-          seq(
+          through(relayV),
-            dataCall(bc, "relay", initPeer),
+          call(1, otherPeer),
-            seq(
+          through(relayV),
-              call(0, initPeer),
+          respCall(bc, ret, initPeer)
-              on(otherPeer, Nil, through(relayV), call(1, otherPeer))
-            ),
-            through(relayV),
-            on(initPeer, relayV :: Nil, respCall(bc, ret, initPeer))
-          )
         ),
-        on(initPeer, relayV :: Nil, xorErrorCall(bc, initPeer))
+        seq(
+          through(relayV),
+          xorErrorCall(bc, initPeer)
+        )
       )
 
     procFC.equalsOrPrintDiff(expectedFC) should be(true)
@@ -137,25 +135,17 @@ class TransformSpec extends AnyFlatSpec with Matchers {
     val res = Transform.forClient(f2, bc): Node
 
     res.equalsOrPrintDiff(
-      on(
+      seq(
-        initPeer,
+        dataCall(bc, "relay", initPeer),
-        relayV :: Nil,
+        Node(
-        seq(
+          CallServiceTag(
-          dataCall(bc, "relay", initPeer),
+            LiteralModel("\"srv1\""),
-          Node(
+            "foo",
-            CallServiceTag(
+            Call(Nil, Some(Call.Export("v", ScalarType.string))),
-              LiteralModel("\"srv1\""),
+            Some(initPeer)
-              "foo",
-              Call(Nil, Some(Call.Export("v", ScalarType.string))),
-              Some(initPeer)
-            )
-          ),
-          on(
-            initPeer,
-            relayV :: Nil,
-            respCall(bc, VarModel("v", ScalarType.string), initPeer)
           )
-        )
+        ),
+        respCall(bc, VarModel("v", ScalarType.string), initPeer)
       )
     ) should be(true)
   }

project/build.properties

@@ -1 +1 @@
-sbt.version=1.5.0
+sbt.version=1.5.1