feat(compiler): Services as abilities [fixes LNG-206] (#873)

* Refactor ServiceSem

* Refactor AbilityIdSem

* Remove tokens from state

* Refactor

* Add mangler

* Fix tests

* Refactor valueToRaw

* ServiceIdTag

* AbilityId -> ServiceId

* Add ServiceType

* Fix defineServiceType

* Refactor resolveArrowDef

* Refactor TypesHelper

* Add ServiceIdTag inlining

* Implement resolution

* Add service as ability passing

* Fix importing services

* Fix cli

* Implement default service

* Remove println

* Fix capture

* Add integration test

* Fix id

* Fix test

* Fix test

* Refactor test

* Do not resolve id

* Refactor FuncArrow creation

* Refactor FuncArrow wrapper creation

* Add named arguments

* Add comment

* ensureIsString -> valueToStringRaw, refactor OnSem

* Resolve services as abilities

* Add name to varNames

* Remove service hack

* Capture services, do not rename captured

* Rename arrows along with values

* Fix CallArrowRaw.map

* Fix unit tests

* Remove service case

* Refactor abilities state

* Propagate rootServiceIds

* Remove unused

* Add comments

* Refactor

* Refactor

* Add test

---------

Co-authored-by: Dima <dmitry.shakhtarin@fluence.ai>

compiler/src/main/scala/aqua/compiler/AquaCompiler.scala

@@ -10,6 +10,7 @@ import aqua.raw.{RawContext, RawPart}
 import aqua.res.AquaRes
 import aqua.semantics.{CompilerState, Semantics}
 import aqua.semantics.header.{HeaderHandler, HeaderSem, Picker}
+
 import cats.data.*
 import cats.data.Validated.{validNec, Invalid, Valid}
 import cats.parse.Parser0

compiler/src/test/scala/aqua/compiler/AquaCompilerSpec.scala

@@ -153,6 +153,7 @@ class AquaCompilerSpec extends AnyFlatSpec with Matchers {
     val canonResult = VarModel("-" + results.name + "-fix-0", CanonStreamType(resultsType.element))
     val flatResult = VarModel("-results-flat-0", ArrayType(ScalarType.string))
     val initPeer = LiteralModel.fromRaw(ValueRaw.InitPeerId)
+    val retVar = VarModel("ret", ScalarType.string)
 
     val expected =
       SeqRes.wrap(
@@ -173,10 +174,11 @@ class AquaCompilerSpec extends AnyFlatSpec with Matchers {
                           "identity",
                           CallRes(
                             LiteralModel.fromRaw(LiteralRaw.quote("hahahahah")) :: Nil,
-                            Some(CallModel.Export(results.name, results.`type`))
+                            Some(CallModel.Export(retVar.name, retVar.`type`))
                           ),
                           peer
                         ).leaf,
+                        ApRes(retVar, CallModel.Export(results.name, results.`type`)).leaf,
                         through(ValueModel.fromRaw(relay)),
                         through(initPeer)
                       ),

integration-tests/aqua/examples/servicesAsAbilities.aqua

@@ -0,0 +1,95 @@
+aqua Test
+
+export test, testCapture, TestService
+
+service TestService("default-id"):
+    getId() -> string
+    concatId(s: string) -> string
+
+ability MatchingAbility:
+    getId() -> string
+    concatId(s: string) -> string
+
+func acceptClosure(closure: string -> string, arg: string) -> string:
+    <- closure(arg)
+
+func acceptAbility{MatchingAbility}(arg: string) -> string:
+    <- MatchingAbility.concatId(arg)
+
+func test() -> []string:
+    result: *string
+
+    -- Test service
+    result <- TestService.concatId("call")
+    capture = TestService.concatId
+    result <- capture("capture call")
+    result <- acceptClosure(TestService.concatId, "accept closure call")
+    result <- acceptAbility{TestService}("accept ability call")
+    
+    -- Test renamed service
+    Renamed = TestService
+    result <- Renamed.concatId("call")
+    captureRenamed = Renamed.concatId
+    result <- captureRenamed("capture call")
+    result <- acceptClosure(Renamed.concatId, "accept closure call")
+    result <- acceptAbility{Renamed}("accept ability call")
+
+    -- Test resolved service
+    TestService "resolved-id-1"
+    result <- TestService.concatId("call")
+    captureResolved = TestService.concatId
+    result <- captureResolved("capture call")
+    result <- acceptClosure(TestService.concatId, "accept closure call")
+    result <- acceptAbility{TestService}("accept ability call")
+
+    -- Test renamed resolved service
+    Renamed1 = TestService
+    result <- Renamed1.concatId("call")
+    captureRenamed1 = Renamed1.concatId
+    result <- captureRenamed1("capture call")
+    result <- acceptClosure(Renamed1.concatId, "accept closure call")
+    result <- acceptAbility{Renamed1}("accept ability call")
+
+    -- Test renamed service again (should save id)
+    result <- Renamed.concatId("call")
+    captureRenamedAgain = Renamed.concatId
+    result <- captureRenamedAgain("capture call")
+    result <- acceptClosure(Renamed.concatId, "accept closure call")
+    result <- acceptAbility{Renamed}("accept ability call")
+
+    -- Test resolved in scope service
+    for i <- ["iter-id-1", "iter-id-2"]:
+        TestService i
+        RenamedI = TestService
+        result <- RenamedI.concatId("call")
+        captureI = RenamedI.concatId
+        result <- captureI("capture call")
+        result <- acceptClosure(RenamedI.concatId, "accept closure call")
+        result <- acceptAbility{RenamedI}("accept ability call")
+
+    -- Test resolved service again (should save id)
+    result <- TestService.concatId("call")
+    captureAgain = TestService.concatId
+    result <- captureAgain("capture call")
+    result <- acceptClosure(TestService.concatId, "accept closure call")
+    result <- acceptAbility{TestService}("accept ability call")
+
+    -- Test re resolved service in same scope
+    TestService "resolved-id-2"
+    result <- TestService.concatId("call")
+    captureReResolved = TestService.concatId
+    result <- captureReResolved("capture call")
+    result <- acceptClosure(TestService.concatId, "accept closure call")
+    result <- acceptAbility{TestService}("accept ability call")
+
+    <- result
+
+func callCapture{MatchingAbility}() -> string, string:
+    TestService "resolved-id-in-capture"
+    res1 <- TestService.concatId("in capture")
+    res2 <- MatchingAbility.concatId("in capture")
+    <- res1, res2
+
+func testCapture() -> string, string:
+    res1, res2 <- callCapture{TestService}()
+    <- res1, res2

integration-tests/src/examples/servicesAsAbilities.ts

@@ -0,0 +1,71 @@
+import {
+  test,
+  testCapture,
+  registerTestService,
+} from "../compiled/examples/servicesAsAbilities.js";
+
+const serviceIds = {
+  default: "default-id",
+  resolved1: "resolved-id-1",
+  resolved2: "resolved-id-2",
+  iter1: "iter-id-1",
+  iter2: "iter-id-2",
+};
+
+const serviceIdsSequence = [
+  serviceIds.default,
+  serviceIds.default,
+  serviceIds.resolved1,
+  serviceIds.resolved1,
+  serviceIds.default,
+  serviceIds.iter1,
+  serviceIds.iter2,
+  serviceIds.resolved1,
+  serviceIds.resolved2,
+];
+
+const msgs = [
+  "call",
+  "capture call",
+  "accept closure call",
+  "accept ability call",
+];
+
+export const expectedServiceResults = serviceIdsSequence.flatMap((id) =>
+  msgs.map((msg) => `${id}: ${msg}`),
+);
+
+export async function servicesAsAbilitiesCall() {
+  Object.entries(serviceIds).forEach(([_key, id], _idx) =>
+    registerTestService(id, {
+      concatId: (s: string) => {
+        return `${id}: ${s}`;
+      },
+      getId: () => {
+        return id;
+      },
+    }),
+  );
+
+  return await test();
+}
+
+export const expectedServiceCaptureResults = [
+  "resolved-id-in-capture: in capture",
+  "default-id: in capture",
+];
+
+export async function servicesAsAbilitiesCaptureCall() {
+  ["resolved-id-in-capture", "default-id"].forEach((id) =>
+    registerTestService(id, {
+      concatId: (s: string) => {
+        return `${id}: ${s}`;
+      },
+      getId: () => {
+        return id;
+      },
+    }),
+  );
+
+  return await testCapture();
+}

model/inline/src/main/scala/aqua/model/inline/ArrowInliner.scala

@@ -5,10 +5,11 @@ import aqua.model.*
 import aqua.model.inline.state.{Arrows, Exports, Mangler}
 import aqua.raw.ops.RawTag
 import aqua.raw.value.{ValueRaw, VarRaw}
-import aqua.types.{AbilityType, ArrowType, BoxType, StreamType, Type}
+import aqua.types.{AbilityType, ArrowType, BoxType, NamedType, StreamType, Type}
 
 import cats.data.StateT
 import cats.data.{Chain, IndexedStateT, State}
+import cats.syntax.functor.*
 import cats.syntax.applicative.*
 import cats.syntax.bifunctor.*
 import cats.syntax.foldable.*
@@ -123,22 +124,22 @@ object ArrowInliner extends Logging {
   /**
    * Get ability fields (vars or arrows) from exports
    *
-   * @param abilityName ability current name in state
+   * @param name ability current name in state
-   * @param abilityNewName ability new name (for renaming)
+   * @param newName ability new name (for renaming)
-   * @param abilityType ability type
+   * @param type ability type
    * @param exports exports state to resolve fields
    * @param fields fields selector
    * @return resolved ability fields (renamed if necessary)
    */
   private def getAbilityFields[T <: Type](
-    abilityName: String,
+    name: String,
-    abilityNewName: Option[String],
+    newName: Option[String],
-    abilityType: AbilityType,
+    `type`: NamedType,
     exports: Map[String, ValueModel]
-  )(fields: AbilityType => Map[String, T]): Map[String, ValueModel] =
+  )(fields: NamedType => Map[String, T]): Map[String, ValueModel] =
-    fields(abilityType).flatMap { case (fName, _) =>
+    fields(`type`).flatMap { case (fName, _) =>
-      val fullName = AbilityType.fullName(abilityName, fName)
+      val fullName = AbilityType.fullName(name, fName)
-      val newFullName = AbilityType.fullName(abilityNewName.getOrElse(abilityName), fName)
+      val newFullName = AbilityType.fullName(newName.getOrElse(name), fName)
 
       Exports
         .getLastValue(fullName, exports)
@@ -179,24 +180,24 @@ object ArrowInliner extends Logging {
   /**
    * Get ability arrows from arrows
    *
-   * @param abilityName ability current name in state
+   * @param name ability current name in state
-   * @param abilityNewName ability new name (for renaming)
+   * @param newName ability new name (for renaming)
-   * @param abilityType ability type
+   * @param type ability type
    * @param exports exports state to resolve fields
    * @param arrows arrows state to resolve arrows
    * @return resolved ability arrows (renamed if necessary)
    */
   private def getAbilityArrows(
-    abilityName: String,
+    name: String,
-    abilityNewName: Option[String],
+    newName: Option[String],
-    abilityType: AbilityType,
+    `type`: NamedType,
     exports: Map[String, ValueModel],
     arrows: Map[String, FuncArrow]
   ): Map[String, FuncArrow] = {
     val get = getAbilityFields(
-      abilityName,
+      name,
-      abilityNewName,
+      newName,
-      abilityType,
+      `type`,
       exports
     )
 
@@ -210,12 +211,12 @@ object ArrowInliner extends Logging {
   }
 
   private def getAbilityArrows[S: Arrows: Exports](
-    abilityName: String,
+    name: String,
-    abilityType: AbilityType
+    `type`: NamedType
   ): State[S, Map[String, FuncArrow]] = for {
     exports <- Exports[S].exports
     arrows <- Arrows[S].arrows
-  } yield getAbilityArrows(abilityName, None, abilityType, exports, arrows)
+  } yield getAbilityArrows(name, None, `type`, exports, arrows)
 
   final case class Renamed[T](
     renames: Map[String, String],
@@ -276,7 +277,22 @@ object ArrowInliner extends Logging {
      * to avoid collisions, then resolve them in context.
      */
     capturedValues <- findNewNames(fn.capturedValues)
-    capturedArrows <- findNewNames(fn.capturedArrows)
+    /**
+     * If arrow correspond to a value,
+     * rename in accordingly to the value
+     */
+    capturedArrowValues = fn.capturedArrows.flatMap { case (arrowName, arrow) =>
+      capturedValues.renames
+        .get(arrowName)
+        .orElse(fn.capturedValues.get(arrowName).as(arrowName))
+        .map(_ -> arrow)
+    }
+    /**
+     * Rename arrows that are not values
+     */
+    capturedArrows <- findNewNames(fn.capturedArrows.filterNot { case (arrowName, _) =>
+      capturedArrowValues.contains(arrowName)
+    })
 
     /**
      * Function defines variables inside its body.
@@ -301,7 +317,12 @@ object ArrowInliner extends Logging {
         defineRenames
     )
 
-    arrowsResolved = arrows ++ capturedArrows.renamed
+    /**
+     * TODO: Optimize resolve.
+     * It seems that resolving whole `exports`
+     * and `arrows` is not necessary.
+     */
+    arrowsResolved = arrows ++ capturedArrowValues ++ capturedArrows.renamed
     exportsResolved = exports ++ data.renamed ++ capturedValues.renamed
 
     tree = fn.body.rename(renaming)
@@ -322,12 +343,13 @@ object ArrowInliner extends Logging {
 
     exports <- Exports[S].exports
     streams <- getOutsideStreamNames
+    arrows = passArrows ++ arrowsFromAbilities
 
     inlineResult <- Exports[S].scope(
       Arrows[S].scope(
         for {
           // Process renamings, prepare environment
-          fn <- ArrowInliner.prelude(arrow, call, exports, passArrows ++ arrowsFromAbilities)
+          fn <- ArrowInliner.prelude(arrow, call, exports, arrows)
           inlineResult <- ArrowInliner.inline(fn, call, streams)
         } yield inlineResult
       )

model/inline/src/main/scala/aqua/model/inline/TagInliner.scala

@@ -413,6 +413,49 @@ object TagInliner extends Logging {
             } yield TagInlined.Empty(prefix = prefix)
           case _ => none
 
+      case ServiceIdTag(id, serviceType, name) =>
+        for {
+          idm <- valueToModel(id)
+          (idModel, idPrefix) = idm
+
+          // Make `FuncArrow` wrappers for service methods
+          methods <- serviceType.fields.toSortedMap.toList.traverse {
+            case (methodName, methodType) =>
+              for {
+                arrowName <- Mangler[S].findAndForbidName(s"$name-$methodName")
+                fn = FuncArrow.fromServiceMethod(
+                  arrowName,
+                  serviceType.name,
+                  methodName,
+                  methodType,
+                  idModel
+                )
+              } yield methodName -> fn
+          }
+
+          // Resolve wrappers in arrows
+          _ <- Arrows[S].resolved(
+            methods.map { case (_, fn) =>
+              fn.funcName -> fn
+            }.toMap
+          )
+
+          // Resolve wrappers in exports
+          _ <- methods.traverse { case (methodName, fn) =>
+            Exports[S].resolveAbilityField(
+              name,
+              methodName,
+              VarModel(fn.funcName, fn.arrowType)
+            )
+          }
+
+          // Resolve service in exports
+          _ <- Exports[S].resolved(
+            name,
+            VarModel(name, serviceType)
+          )
+        } yield TagInlined.Empty(prefix = idPrefix)
+
       case _: SeqGroupTag => pure(SeqModel)
       case ParTag.Detach => pure(DetachModel)
       case _: ParGroupTag => pure(ParModel)

model/inline/src/main/scala/aqua/model/inline/raw/ApplyPropertiesRawInliner.scala

@@ -59,65 +59,57 @@ object ApplyPropertiesRawInliner extends RawInliner[ApplyPropertyRaw] with Loggi
 
   private def unfoldAbilityProperty[S: Mangler: Exports: Arrows](
     varModel: VarModel,
-    abilityType: AbilityType,
+    abilityType: NamedType,
     p: PropertyRaw
-  ): State[S, (VarModel, Inline)] = {
+  ): State[S, (VarModel, Inline)] = p match {
-    p match {
+    case IntoArrowRaw(arrowName, t, arguments) =>
-      case IntoArrowRaw(arrowName, t, arguments) =>
+      val arrowType = abilityType.fields
-        val arrowType = abilityType.fields
+        .lookup(arrowName)
-          .lookup(arrowName)
+        .collect { case at @ ArrowType(_, _) =>
-          .collect { case at @ ArrowType(_, _) =>
+          at
-            at
+        }
-          }
+        .getOrElse {
-          .getOrElse {
+          logger.error(s"Inlining, cannot find arrow $arrowName in $varModel")
-            logger.error(s"Inlining, cannot find arrow $arrowName in ability $varModel")
+          ArrowType(NilType, NilType)
-            ArrowType(NilType, NilType)
+        }
-          }
+      for {
-        for {
+        callArrow <- CallArrowRawInliner(
-          callArrow <- CallArrowRawInliner(
+          CallArrowRaw.func(
-            CallArrowRaw(
+            funcName = AbilityType.fullName(varModel.name, arrowName),
-              None,
+            baseType = arrowType,
-              AbilityType.fullName(varModel.name, arrowName),
+            arguments = arguments
-              arguments,
-              arrowType,
-              None
-            )
           )
-          result <- callArrow match {
+        )
-            case (vm: VarModel, inl) =>
+        result <- callArrow match {
-              State.pure((vm, inl))
+          case (vm: VarModel, inl) =>
-            case (lm: LiteralModel, inl) =>
+            State.pure((vm, inl))
-              flatLiteralWithProperties(lm, inl, Chain.empty).flatMap { case (vm, inline) =>
+          case (lm: LiteralModel, inl) =>
-                Exports[S].resolved(vm.name, vm).map(_ => (vm, inline))
+            flatLiteralWithProperties(lm, inl, Chain.empty).flatMap { case (vm, inline) =>
-              }
+              Exports[S].resolved(vm.name, vm).map(_ => (vm, inline))
-          }
+            }
-        } yield {
-          result
         }
-      case IntoFieldRaw(fieldName, at @ AbilityType(abName, fields)) =>
+      } yield result
-        (VarModel(AbilityType.fullName(varModel.name, fieldName), at), Inline.empty).pure
+    case IntoFieldRaw(fieldName, at @ AbilityType(abName, fields)) =>
-      case IntoFieldRaw(fieldName, t) =>
+      (VarModel(AbilityType.fullName(varModel.name, fieldName), at), Inline.empty).pure
-        for {
+    case IntoFieldRaw(fieldName, t) =>
-          abilityField <- Exports[S].getAbilityField(varModel.name, fieldName)
+      for {
-          result <- abilityField match {
+        abilityField <- Exports[S].getAbilityField(varModel.name, fieldName)
-            case Some(vm: VarModel) =>
+        result <- abilityField match {
-              State.pure((vm, Inline.empty))
+          case Some(vm: VarModel) =>
-            case Some(lm: LiteralModel) =>
+            State.pure((vm, Inline.empty))
-              flatLiteralWithProperties(lm, Inline.empty, Chain.empty)
+          case Some(lm: LiteralModel) =>
-            case _ =>
+            flatLiteralWithProperties(lm, Inline.empty, Chain.empty)
-              Exports[S].getKeys.flatMap { keys =>
+          case _ =>
-                logger.error(
+            Exports[S].getKeys.flatMap { keys =>
-                  s"Inlining, cannot find field ${AbilityType
+              logger.error(
-                    .fullName(varModel.name, fieldName)} in ability $varModel. Available: $keys"
+                s"Inlining, cannot find field ${AbilityType
-                )
+                  .fullName(varModel.name, fieldName)} in ability $varModel. Available: $keys"
-                flatLiteralWithProperties(LiteralModel.quote(""), Inline.empty, Chain.empty)
+              )
-              }
+              flatLiteralWithProperties(LiteralModel.quote(""), Inline.empty, Chain.empty)
+            }
 
-          }
-        } yield {
-          result
         }
-    }
+      } yield result
   }
 
   private[inline] def unfoldProperty[S: Mangler: Exports: Arrows](
@@ -284,9 +276,9 @@ object ApplyPropertiesRawInliner extends RawInliner[ApplyPropertyRaw] with Loggi
       case (_, _) =>
         unfold(raw).flatMap {
           case (vm: VarModel, prevInline) =>
-            unfoldProperties(prevInline, vm, properties, propertiesAllowed).map { case (v, i) =>
+            unfoldProperties(prevInline, vm, properties, propertiesAllowed)
-              v -> i
+              // To coerce types
-            }
+              .map(identity)
           case (l: LiteralModel, inline) =>
             flatLiteralWithProperties(
               l,

model/inline/src/main/scala/aqua/model/inline/state/Arrows.scala

@@ -32,12 +32,8 @@ trait Arrows[S] extends Scoped[S] {
     for {
       exps <- Exports[S].exports
       arrs <- arrows
-      //   _ = println(s"Resolved arrow: ${arrow.name}")
-      //   _ = println(s"Captured var names: ${arrow.capturedVars}")
       captuedVars = exps.filterKeys(arrow.capturedVars).toMap
       capturedArrows = arrs.filterKeys(arrow.capturedVars).toMap
-      //   _ = println(s"Captured vars: ${captuedVars}")
-      //   _ = println(s"Captured arrows: ${capturedArrows}")
       funcArrow = FuncArrow.fromRaw(arrow, capturedArrows, captuedVars, topology)
       _ <- save(arrow.name, funcArrow)
     } yield ()

model/inline/src/main/scala/aqua/model/inline/state/Exports.scala

@@ -2,7 +2,8 @@ package aqua.model.inline.state
 
 import aqua.model.{LiteralModel, ValueModel, VarModel}
 import aqua.model.ValueModel.Ability
-import aqua.types.AbilityType
+import aqua.types.{AbilityType, NamedType}
+
 import cats.data.{NonEmptyList, State}
 
 /**
@@ -122,7 +123,7 @@ trait Exports[S] extends Scoped[S] {
 }
 
 object Exports {
-  def apply[S](implicit exports: Exports[S]): Exports[S] = exports
+  def apply[S](using exports: Exports[S]): Exports[S] = exports
 
   // Get last linked VarModel
   def getLastValue(name: String, state: Map[String, ValueModel]): Option[ValueModel] = {
@@ -143,7 +144,7 @@ object Exports {
     private def getAbilityPairs(
       oldName: String,
       newName: String,
-      at: AbilityType,
+      at: NamedType,
       state: Map[String, ValueModel]
     ): NonEmptyList[(String, ValueModel)] = {
       at.fields.toNel.flatMap {

model/inline/src/test/scala/aqua/model/inline/RawBuilder.scala

@@ -6,16 +6,16 @@ import aqua.types.{ArrowType, ProductType, ScalarType}
 object RawBuilder {
 
   def add(l: ValueRaw, r: ValueRaw): ValueRaw =
-    CallArrowRaw(
+    CallArrowRaw.service(
-      ability = Some("math"),
+      abilityName = "math",
-      name = "add",
+      serviceId = LiteralRaw.quote("math"),
-      arguments = List(l, r),
+      funcName = "add",
       baseType = ArrowType(
         ProductType(List(ScalarType.i64, ScalarType.i64)),
         ProductType(
           List(l.`type` `∪` r.`type`)
         )
       ),
-      serviceId = Some(LiteralRaw.quote("math"))
+      arguments = List(l, r)
     )
 }

model/raw/src/main/scala/aqua/raw/RawContext.scala

@@ -2,7 +2,7 @@ package aqua.raw
 
 import aqua.raw.arrow.FuncRaw
 import aqua.raw.value.ValueRaw
-import aqua.types.{StructType, Type, AbilityType}
+import aqua.types.{AbilityType, StructType, Type}
 
 import cats.Monoid
 import cats.Semigroup
@@ -61,8 +61,9 @@ case class RawContext(
     all(_.services)
 
   lazy val types: Map[String, Type] =
-    collectPartsMap { case t: TypeRaw =>
+    collectPartsMap {
-      t.`type`
+      case t: TypeRaw => t.`type`
+      case s: ServiceRaw => s.`type`
     }
 
   lazy val allTypes: Map[String, Type] =

model/raw/src/main/scala/aqua/raw/ServiceRaw.scala

@@ -1,15 +1,14 @@
 package aqua.raw
 
-import aqua.types.{ArrowType, StructType}
+import aqua.types.ServiceType
-import cats.data.NonEmptyMap
 import aqua.raw.value.ValueRaw
 
 case class ServiceRaw(
   name: String,
-  arrows: NonEmptyMap[String, ArrowType],
+  `type`: ServiceType,
   defaultId: Option[ValueRaw]
 ) extends RawPart {
-  def rawPartType: StructType = StructType(name, arrows)
+  def rawPartType: ServiceType = `type`
 
   override def rename(s: String): RawPart = copy(name = s)
 

model/raw/src/main/scala/aqua/raw/ops/RawTag.scala

@@ -4,7 +4,7 @@ import aqua.raw.arrow.FuncRaw
 import aqua.raw.ops.RawTag.Tree
 import aqua.raw.value.{CallArrowRaw, ValueRaw}
 import aqua.tree.{TreeNode, TreeNodeCompanion}
-import aqua.types.{ArrowType, DataType}
+import aqua.types.{ArrowType, DataType, ServiceType}
 
 import cats.Show
 import cats.data.{Chain, NonEmptyList}
@@ -20,7 +20,7 @@ sealed trait RawTag extends TreeNode[RawTag] {
   def restrictsVarNames: Set[String] = Set.empty
 
   // All variable names introduced by this tag
-  def definesVarNames: Set[String] = exportsVarNames ++ restrictsVarNames
+  final def definesVarNames: Set[String] = exportsVarNames ++ restrictsVarNames
 
   // Variable names used by this tag (not introduced by it)
   def usesVarNames: Set[String] = Set.empty
@@ -208,6 +208,22 @@ case class CallArrowRawTag(
 
 object CallArrowRawTag {
 
+  def ability(
+    abilityName: String,
+    funcName: String,
+    call: Call,
+    arrowType: ArrowType
+  ): CallArrowRawTag =
+    CallArrowRawTag(
+      call.exportTo,
+      CallArrowRaw.ability(
+        abilityName,
+        funcName,
+        arrowType,
+        call.args
+      )
+    )
+
   def service(
     serviceId: ValueRaw,
     fnName: String,
@@ -231,12 +247,10 @@ object CallArrowRawTag {
   def func(fnName: String, call: Call): CallArrowRawTag =
     CallArrowRawTag(
       call.exportTo,
-      CallArrowRaw(
+      CallArrowRaw.func(
-        None,
+        funcName = fnName,
-        fnName,
+        baseType = call.arrowType,
-        call.args,
+        arguments = call.args
-        call.arrowType,
-        None
       )
     )
 }
@@ -307,15 +321,27 @@ object EmptyTag extends NoExecTag {
   override def mapValues(f: ValueRaw => ValueRaw): RawTag = this
 }
 
-case class AbilityIdTag(
+/**
+ * Tag for `Service "id"` expression.
+ * For each such expression new ability
+ * is created with unique name (@p name).
+ *
+ * @param value value of service ID
+ * @param serviceType type of service
+ * @param name **rename** of service
+ */
+case class ServiceIdTag(
   value: ValueRaw,
-  service: String
+  serviceType: ServiceType,
+  name: String
 ) extends NoExecTag {
 
   override def usesVarNames: Set[String] = value.varNames
 
+  override def exportsVarNames: Set[String] = Set(name)
+
   override def mapValues(f: ValueRaw => ValueRaw): RawTag =
-    AbilityIdTag(value.map(f), service)
+    ServiceIdTag(value.map(f), serviceType, name)
 }
 
 case class PushToStreamTag(operand: ValueRaw, exportTo: Call.Export) extends RawTag {

model/raw/src/main/scala/aqua/raw/value/ValueRaw.scala

@@ -250,12 +250,14 @@ case class CallArrowRaw(
   override def map(f: ValueRaw => ValueRaw): ValueRaw =
     f(
       copy(
-        arguments = arguments.map(f),
+        arguments = arguments.map(_.map(f)),
-        serviceId = serviceId.map(f)
+        serviceId = serviceId.map(_.map(f))
       )
     )
 
-  override def varNames: Set[String] = arguments.flatMap(_.varNames).toSet
+  override def varNames: Set[String] = name.some
+    .filterNot(_ => ability.isDefined || serviceId.isDefined)
+    .toSet ++ arguments.flatMap(_.varNames).toSet
 
   override def renameVars(map: Map[String, String]): ValueRaw =
     copy(

model/res/src/main/scala/aqua/res/ServiceRes.scala

@@ -11,7 +11,7 @@ object ServiceRes {
   def fromModel(sm: ServiceModel): ServiceRes =
     ServiceRes(
       name = sm.name,
-      members = sm.arrows.toNel.toList,
+      members = sm.`type`.arrows.toList,
       defaultId = sm.defaultId.collect {
         case LiteralModel(value, t) if ScalarType.string.acceptsValueOf(t) =>
           value

model/src/main/scala/aqua/model/AquaContext.scala

@@ -5,15 +5,19 @@ import aqua.raw.ops.CallArrowRawTag
 import aqua.raw.value.ValueRaw
 import aqua.raw.value.CallArrowRaw
 import aqua.raw.{ConstantRaw, RawContext, RawPart, ServiceRaw, TypeRaw}
-import aqua.types.{StructType, Type}
+import aqua.types.{AbilityType, StructType, Type}
+
 import cats.Monoid
 import cats.data.NonEmptyMap
 import cats.data.Chain
 import cats.kernel.Semigroup
 import cats.syntax.functor.*
+import cats.syntax.foldable.*
+import cats.syntax.traverse.*
+import cats.syntax.bifunctor.*
 import cats.syntax.monoid.*
+import cats.syntax.option.*
 import scribe.Logging
-
 import scala.collection.immutable.SortedMap
 
 case class AquaContext(
@@ -26,31 +30,76 @@ case class AquaContext(
   services: Map[String, ServiceModel]
 ) {
 
-  private def prefixFirst[T](prefix: String, pair: (String, T)): (String, T) =
-    (prefix + pair._1, pair._2)
-
   // TODO: it's a duplicate
-  private def all[T](what: AquaContext => Map[String, T], prefix: String = ""): Map[String, T] =
+  private def all[T](
-    abilities
+    what: AquaContext => Map[String, T],
-      .foldLeft(what(this)) { case (ts, (k, v)) =>
+    prefix: String = ""
-        ts ++ v.all(what, k + ".")
+  ): Map[String, T] = (
-      }
+    what(this) ++ abilities.toList.foldMap { case (k, v) =>
-      .map(prefixFirst(prefix, _))
+      v.all(what, k + ".").toList
+    }
+  ).map(_.leftMap(prefix + _)).toMap
 
   lazy val allValues: Map[String, ValueModel] =
-    all(_.values)
+    all(_.values) ++
+      /**
+       * Add values from services that have default ID
+       * So that they will be available in functions.
+       */
+      services.flatMap { case (srvName, srv) =>
+        srv.defaultId.toList.flatMap(_ =>
+          srv.`type`.arrows.map { case (arrowName, arrowType) =>
+            val fullName = AbilityType.fullName(srvName, arrowName)
+
+            fullName -> VarModel(
+              fullName,
+              arrowType
+            )
+          }.updated(
+            srvName,
+            VarModel(
+              srvName,
+              srv.`type`
+            )
+          )
+        )
+      }
 
   lazy val allFuncs: Map[String, FuncArrow] =
-    all(_.funcs)
+    all(_.funcs) ++
+      /**
+       * Add functions from services that have default ID
+       * So that they will be available in functions.
+       */
+      services.flatMap { case (srvName, srv) =>
+        srv.defaultId.toList.flatMap(id =>
+          srv.`type`.arrows.map { case (arrowName, arrowType) =>
+            val fullName = AbilityType.fullName(srvName, arrowName)
+
+            fullName -> FuncArrow.fromServiceMethod(
+              fullName,
+              srvName,
+              arrowName,
+              arrowType,
+              id
+            )
+          }
+        )
+      }
 
   private def pickOne[T](
     name: String,
     newName: String,
     ctx: Map[String, T],
     add: (AquaContext, Map[String, T]) => AquaContext
-  ): AquaContext = {
+  ): AquaContext = ctx
-    ctx.get(name).fold(AquaContext.blank)(t => add(AquaContext.blank, Map(newName -> t)))
+    .get(name)
-  }
+    .fold(AquaContext.blank)(t =>
+      add(
+        AquaContext.blank,
+        Map(newName -> t)
+      )
+    )
 
   def pick(name: String, maybeRename: Option[String]): AquaContext = {
     val newName = maybeRename.getOrElse(name)
@@ -68,7 +117,7 @@ object AquaContext extends Logging {
     lazy val size: Long = data.size
 
     def get(ctx: RawContext): Option[AquaContext] =
-      data.find(_._1 eq ctx).map(_._2)
+      data.collectFirst { case (rawCtx, aquaCtx) if rawCtx eq ctx => aquaCtx }
 
     def updated(ctx: RawContext, aCtx: AquaContext): Cache = copy(data :+ (ctx -> aCtx))
   }
@@ -91,11 +140,10 @@ object AquaContext extends Logging {
         x.services ++ y.services
       )
 
-  //
   def fromService(sm: ServiceRaw, serviceId: ValueRaw): AquaContext =
     blank.copy(
       module = Some(sm.name),
-      funcs = sm.arrows.toSortedMap.map { case (fnName, arrowType) =>
+      funcs = sm.`type`.arrows.map { case (fnName, arrowType) =>
         val (args, call, ret) = ArgsCall.arrowToArgsCallRet(arrowType)
         fnName ->
           FuncArrow(
@@ -192,13 +240,16 @@ object AquaContext extends Logging {
               logger.trace("Adding service " + m.name)
               val (pctx, pcache) = fromRawContext(partContext, ctxCache)
               logger.trace("Got " + m.name + " from raw")
-              val id = m.defaultId.map(ValueModel.fromRaw).map(_.resolveWith(pctx.allValues))
+              val id = m.defaultId
-              val srv = ServiceModel(m.name, m.arrows, id)
+                .map(ValueModel.fromRaw)
+                .map(_.resolveWith(pctx.allValues))
+              val srv = ServiceModel(m.name, m.`type`, id)
               val add =
                 blank
                   .copy(
-                    abilities =
+                    abilities = m.defaultId
-                      m.defaultId.fold(Map.empty)(id => Map(m.name -> fromService(m, id))),
+                      .map(id => Map(m.name -> fromService(m, id)))
+                      .orEmpty,
                     services = Map(m.name -> srv)
                   )
 

model/src/main/scala/aqua/model/ArgsCall.scala

@@ -1,6 +1,7 @@
 package aqua.model
 
 import aqua.model.{ValueModel, VarModel}
+import aqua.model.ValueModel.Ability
 import aqua.raw.ops.Call
 import aqua.raw.value.{ValueRaw, VarRaw}
 import aqua.types.*
@@ -39,11 +40,11 @@ case class ArgsCall(args: ProductType, callWith: List[ValueModel]) {
     }.toMap
 
   /**
-   * Ability arguments as mapping
+   * Ability and service arguments as mapping
-   * Name of argument -> (variable passed in the call, ability type)
+   * Name of argument -> (variable passed in the call, type)
    */
-  lazy val abilityArgs: Map[String, (VarModel, AbilityType)] =
+  lazy val abilityArgs: Map[String, (VarModel, NamedType)] =
-    zipped.collect { case ((name, _), vr @ VarModel(_, t @ AbilityType(_, _), _)) =>
+    zipped.collect { case ((name, _), vr @ Ability(_, t, _)) =>
       name -> (vr, t)
     }.toMap
 

model/src/main/scala/aqua/model/CallModel.scala

@@ -1,17 +1,18 @@
 package aqua.model
 
 import aqua.raw.ops.Call
-import aqua.types.{ArrowType, AbilityType, Type}
+import aqua.types.{ArrowType, NamedType, Type}
+import aqua.model.ValueModel.{Ability, Arrow}
 
 // TODO docs
 case class CallModel(args: List[ValueModel], exportTo: List[CallModel.Export]) {
   override def toString: String = s"[${args.mkString(" ")}] ${exportTo.mkString(" ")}"
 
-  def arrowArgNames: Set[String] = args.collect { case VarModel(m, _: ArrowType, _) =>
+  def arrowArgNames: Set[String] = args.collect { case Arrow(m, _) =>
     m
   }.toSet
 
-  def abilityArgs: List[(String, AbilityType)] = args.collect { case VarModel(m, t: AbilityType, _) =>
+  def abilityArgs: List[(String, NamedType)] = args.collect { case Ability(m, t, _) =>
     (m, t)
   }
 
@@ -21,7 +22,7 @@ case class CallModel(args: List[ValueModel], exportTo: List[CallModel.Export]) {
 object CallModel {
 
   case class Export(name: String, `type`: Type) {
-    
+
     def asVar: VarModel = VarModel(name, `type`)
 
     override def toString: String = s"$name:${`type`}"

model/src/main/scala/aqua/model/FuncArrow.scala

@@ -2,9 +2,9 @@ package aqua.model
 
 import aqua.raw.Raw
 import aqua.raw.arrow.FuncRaw
-import aqua.raw.ops.RawTag
+import aqua.raw.ops.{Call, CallArrowRawTag, RawTag}
 import aqua.raw.value.{ValueRaw, VarRaw}
-import aqua.types.{ArrowType, Type}
+import aqua.types.{ArrowType, ServiceType, Type}
 
 case class FuncArrow(
   funcName: String,
@@ -42,4 +42,49 @@ object FuncArrow {
       constants,
       topology
     )
+
+  /**
+   * Create function - wrapper around a service method
+   *
+   * @param funcName name of the function
+   * @param serviceName name of the service
+   * @param methodName name of the service method to wrap
+   * @param methodType type of the service method to wrap
+   * @param idValue resolved value of the service id
+   * @return `FuncArrow` wrapper for the service method
+   */
+  def fromServiceMethod(
+    funcName: String,
+    serviceName: String,
+    methodName: String,
+    methodType: ArrowType,
+    idValue: ValueModel
+  ): FuncArrow = {
+    val id = VarRaw("id", idValue.`type`)
+    val retVar = methodType.res.map(t => VarRaw("ret", t))
+
+    val call = Call(
+      methodType.domain.toLabelledList().map(VarRaw.apply),
+      retVar.map(r => Call.Export(r.name, r.`type`)).toList
+    )
+    val body = CallArrowRawTag.service(
+      serviceId = id,
+      fnName = methodName,
+      call = call,
+      name = serviceName,
+      arrowType = methodType
+    )
+
+    FuncArrow(
+      funcName = funcName,
+      body = body.leaf,
+      arrowType = methodType,
+      ret = retVar.toList,
+      capturedArrows = Map.empty,
+      capturedValues = Map(
+        id.name -> idValue
+      ),
+      capturedTopology = None
+    )
+  }
 }

model/src/main/scala/aqua/model/ServiceModel.scala

@@ -1,10 +1,9 @@
 package aqua.model
 
-import aqua.types.ArrowType
+import aqua.types.ServiceType
-import cats.data.NonEmptyMap
 
 case class ServiceModel(
   name: String,
-  arrows: NonEmptyMap[String, ArrowType],
+  `type`: ServiceType,
   defaultId: Option[ValueModel]
 )

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

@@ -51,11 +51,21 @@ object ValueModel {
     case _ => ???
   }
 
+  object Arrow {
+
+    def unapply(vm: VarModel): Option[(String, ArrowType)] =
+      vm match {
+        case VarModel(name, t: ArrowType, _) =>
+          (name, t).some
+        case _ => none
+      }
+  }
+
   object Ability {
 
-    def unapply(vm: VarModel): Option[(String, AbilityType, Chain[PropertyModel])] =
+    def unapply(vm: VarModel): Option[(String, NamedType, Chain[PropertyModel])] =
       vm match {
-        case VarModel(name, t@AbilityType(_, _), properties) =>
+        case VarModel(name, t: (AbilityType | ServiceType), properties) =>
           (name, t, properties).some
         case _ => none
       }

parser/src/main/scala/aqua/parser/expr/func/ArrowExpr.scala

@@ -20,7 +20,7 @@ case class ArrowExpr[F[_]](arrowTypeExpr: ArrowTypeToken[F])
 object ArrowExpr extends Expr.AndIndented {
 
   val funcChildren: List[Expr.Lexem] =
-    AbilityIdExpr ::
+    ServiceIdExpr ::
       PushToStreamExpr ::
       ForExpr ::
       Expr.defer(OnExpr) ::

parser/src/main/scala/aqua/parser/expr/func/ServiceIdExpr.scala

@@ -1,7 +1,7 @@
 package aqua.parser.expr.func
 
 import aqua.parser.Expr
-import aqua.parser.expr.func.AbilityIdExpr
+import aqua.parser.expr.func.ServiceIdExpr
 import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{NamedTypeToken, ValueToken}
 import aqua.parser.lift.LiftParser
@@ -10,19 +10,19 @@ import cats.{~>, Comonad}
 import aqua.parser.lift.Span
 import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
 
-case class AbilityIdExpr[F[_]](ability: NamedTypeToken[F], id: ValueToken[F])
+case class ServiceIdExpr[F[_]](service: NamedTypeToken[F], id: ValueToken[F])
-    extends Expr[F](AbilityIdExpr, ability) {
+    extends Expr[F](ServiceIdExpr, service) {
 
-  def mapK[K[_]: Comonad](fk: F ~> K): AbilityIdExpr[K] =
+  def mapK[K[_]: Comonad](fk: F ~> K): ServiceIdExpr[K] =
-    copy(ability.copy(fk(ability.name)), id.mapK(fk))
+    copy(service.copy(fk(service.name)), id.mapK(fk))
 
 }
 
-object AbilityIdExpr extends Expr.Leaf {
+object ServiceIdExpr extends Expr.Leaf {
 
-  override val p: P[AbilityIdExpr[Span.S]] =
+  override val p: P[ServiceIdExpr[Span.S]] =
     ((NamedTypeToken.dotted <* ` `) ~ ValueToken.`value`).map { case (ability, id) =>
-      AbilityIdExpr(ability, id)
+      ServiceIdExpr(ability, id)
     }
 
 }

parser/src/test/scala/aqua/AquaSpec.scala

@@ -118,8 +118,8 @@ trait AquaSpec extends EitherValues {
   def parseUse(str: String): UseFromExpr[Id] =
     UseFromExpr.p.parseAll(str).value.mapK(spanToId)
 
-  def parseAbId(str: String): AbilityIdExpr[Id] =
+  def parseServiceId(str: String): ServiceIdExpr[Id] =
-    AbilityIdExpr.p.parseAll(str).value.mapK(spanToId)
+    ServiceIdExpr.p.parseAll(str).value.mapK(spanToId)
 
   def parseOn(str: String): OnExpr[Id] =
     OnExpr.p.parseAll(str).value.mapK(spanToId)

parser/src/test/scala/aqua/parser/AbilityIdExprSpec.scala

@@ -1,9 +1,10 @@
 package aqua.parser
 
 import aqua.AquaSpec
-import aqua.parser.expr.func.AbilityIdExpr
+import aqua.parser.expr.func.ServiceIdExpr
 import aqua.parser.lexer.LiteralToken
 import aqua.types.LiteralType
+
 import cats.Id
 import org.scalatest.flatspec.AnyFlatSpec
 import org.scalatest.matchers.should.Matchers
@@ -12,20 +13,20 @@ class AbilityIdExprSpec extends AnyFlatSpec with Matchers with AquaSpec {
   import AquaSpec._
 
   "abilities" should "be parsed" in {
-    parseAbId("Ab a") should be(
+    parseServiceId("Ab a") should be(
-      AbilityIdExpr[Id](toNamedType("Ab"), toVar("a"))
+      ServiceIdExpr[Id](toNamedType("Ab"), toVar("a"))
     )
 
-    parseAbId("Ab \"a\"") should be(
+    parseServiceId("Ab \"a\"") should be(
-      AbilityIdExpr[Id](toNamedType("Ab"), LiteralToken[Id]("\"a\"", LiteralType.string))
+      ServiceIdExpr[Id](toNamedType("Ab"), LiteralToken[Id]("\"a\"", LiteralType.string))
     )
 
-    parseAbId("Ab 1") should be(
+    parseServiceId("Ab 1") should be(
-      AbilityIdExpr[Id](toNamedType("Ab"), toNumber(1))
+      ServiceIdExpr[Id](toNamedType("Ab"), toNumber(1))
     )
 
-    parseAbId("Ab a.id") should be(
+    parseServiceId("Ab a.id") should be(
-      AbilityIdExpr[Id](toNamedType("Ab"), toVarLambda("a", List("id")))
+      ServiceIdExpr[Id](toNamedType("Ab"), toVarLambda("a", List("id")))
     )
   }
 

parser/src/test/scala/aqua/parser/FuncExprSpec.scala

@@ -2,17 +2,13 @@ package aqua.parser
 
 import aqua.AquaSpec
 import aqua.parser.expr.*
-import aqua.parser.expr.func.{AbilityIdExpr, ArrowExpr, CallArrowExpr, IfExpr, OnExpr, ReturnExpr}
+import aqua.parser.expr.func.*
-import aqua.parser.lexer.{
+import aqua.parser.lexer.*
-  ArrowTypeToken,
-  BasicTypeToken,
-  CallArrowToken,
-  LiteralToken,
-  Token,
-  VarToken
-}
 import aqua.parser.lift.LiftParser.Implicits.idLiftParser
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
 import aqua.types.ScalarType.*
+
 import cats.Id
 import cats.data.{Chain, NonEmptyList}
 import cats.data.Chain.*
@@ -27,11 +23,6 @@ import cats.Eval
 
 import scala.collection.mutable
 import scala.language.implicitConversions
-import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
-import aqua.parser.lexer.PropertyToken
-import aqua.parser.lexer.IntoArrow
-import aqua.parser.expr.func.AssignmentExpr
 
 class FuncExprSpec extends AnyFlatSpec with Matchers with Inside with Inspectors with AquaSpec {
   import AquaSpec.{given, *}
@@ -123,7 +114,7 @@ class FuncExprSpec extends AnyFlatSpec with Matchers with Inside with Inspectors
         )
       )
     )
-    ifBody(1).head.mapK(spanToId) should be(AbilityIdExpr(toNamedType("Peer"), toStr("some id")))
+    ifBody(1).head.mapK(spanToId) should be(ServiceIdExpr(toNamedType("Peer"), toStr("some id")))
     ifBody(2).head.mapK(spanToId) should be(
       CallArrowExpr(Nil, CallArrowToken("call", List(toBool(true))))
     )

parser/src/test/scala/aqua/parser/head/FromSpec.scala

@@ -1,7 +1,7 @@
 package aqua.parser.head
 
 import aqua.AquaSpec
-import aqua.parser.expr.func.AbilityIdExpr
+import aqua.parser.expr.func.ServiceIdExpr
 import aqua.parser.lexer.{LiteralToken, Token}
 import aqua.parser.lift.LiftParser.Implicits.*
 import aqua.types.LiteralType

parser/src/test/scala/aqua/parser/head/ImportFromSpec.scala

@@ -1,7 +1,7 @@
 package aqua.parser.head
 
 import aqua.AquaSpec
-import aqua.parser.expr.func.AbilityIdExpr
+import aqua.parser.expr.func.ServiceIdExpr
 import aqua.parser.lexer.{LiteralToken, Token}
 import aqua.parser.lift.LiftParser.Implicits.*
 import aqua.types.LiteralType
@@ -23,8 +23,7 @@ class ImportFromSpec extends AnyFlatSpec with Matchers with AquaSpec {
       )
     )
 
-    HeadExpr
+    HeadExpr.ast
-      .ast
       .parseAll(s"""import MyModule, func as fn from "file.aqua"
                    |""".stripMargin)
       .value
@@ -32,7 +31,8 @@ class ImportFromSpec extends AnyFlatSpec with Matchers with AquaSpec {
       .value
       .headOption
       .get
-      .head.mapK(spanToId) should be(
+      .head
+      .mapK(spanToId) should be(
       ImportFromExpr(
         NonEmptyList.fromListUnsafe(
           Right(toAb("MyModule") -> None) :: Left(toName("func") -> Some(toName("fn"))) :: Nil

parser/src/test/scala/aqua/parser/head/ModuleSpec.scala

@@ -1,7 +1,7 @@
 package aqua.parser.head
 
 import aqua.AquaSpec
-import aqua.parser.expr.func.AbilityIdExpr
+import aqua.parser.expr.func.ServiceIdExpr
 import aqua.parser.lexer.{LiteralToken, Token}
 import aqua.types.LiteralType
 import cats.Id
@@ -22,12 +22,12 @@ class ModuleSpec extends AnyFlatSpec with Matchers with AquaSpec {
       )
     )
 
-    HeadExpr
+    HeadExpr.ast
-      .ast
       .parseAll(s"""module MyModule declares *
                    |""".stripMargin)
       .value
-      .head.mapK(spanToId) should be(
+      .head
+      .mapK(spanToId) should be(
       ModuleExpr(
         toAb("MyModule"),
         Some(Token.lift[Id, Unit](())),

parser/src/test/scala/aqua/parser/head/UseSpec.scala

@@ -1,7 +1,7 @@
 package aqua.parser.head
 
 import aqua.AquaSpec
-import aqua.parser.expr.func.AbilityIdExpr
+import aqua.parser.expr.func.ServiceIdExpr
 import aqua.parser.lexer.{LiteralToken, Token}
 import aqua.parser.lift.LiftParser.Implicits.*
 import aqua.types.LiteralType

semantics/src/main/scala/aqua/semantics/CompilerState.scala

@@ -8,6 +8,7 @@ import aqua.semantics.rules.definitions.DefinitionsState
 import aqua.semantics.rules.locations.LocationsState
 import aqua.semantics.rules.names.NamesState
 import aqua.semantics.rules.types.TypesState
+import aqua.semantics.rules.mangler.ManglerState
 import aqua.semantics.rules.errors.ReportErrors
 
 import cats.Semigroup
@@ -19,6 +20,7 @@ import monocle.macros.GenLens
 
 case class CompilerState[S[_]](
   errors: Chain[SemanticError[S]] = Chain.empty[SemanticError[S]],
+  mangler: ManglerState = ManglerState(),
   names: NamesState[S] = NamesState[S](),
   abilities: AbilitiesState[S] = AbilitiesState[S](),
   types: TypesState[S] = TypesState[S](),
@@ -42,6 +44,9 @@ object CompilerState {
   given [S[_]]: Lens[CompilerState[S], AbilitiesState[S]] =
     GenLens[CompilerState[S]](_.abilities)
 
+  given [S[_]]: Lens[CompilerState[S], ManglerState] =
+    GenLens[CompilerState[S]](_.mangler)
+
   given [S[_]]: Lens[CompilerState[S], TypesState[S]] =
     GenLens[CompilerState[S]](_.types)
 
@@ -60,7 +65,7 @@ object CompilerState {
         st.focus(_.errors).modify(_.append(RulesViolated(token, hints)))
     }
 
-  implicit def compilerStateMonoid[S[_]]: Monoid[St[S]] = new Monoid[St[S]] {
+  given [S[_]]: Monoid[St[S]] with {
     override def empty: St[S] = State.pure(Raw.Empty("compiler state monoid empty"))
 
     override def combine(x: St[S], y: St[S]): St[S] = for {
@@ -69,6 +74,7 @@ object CompilerState {
       _ <- State.set(
         CompilerState[S](
           a.errors ++ b.errors,
+          a.mangler |+| b.mangler,
           a.names |+| b.names,
           a.abilities |+| b.abilities,
           a.types |+| b.types,

semantics/src/main/scala/aqua/semantics/ExprSem.scala

@@ -27,7 +27,7 @@ object ExprSem {
     L: LocationsAlgebra[S, G]
   ): Prog[G, Raw] =
     expr match {
-      case expr: AbilityIdExpr[S] => new AbilityIdSem(expr).program[G]
+      case expr: ServiceIdExpr[S] => new ServiceIdSem(expr).program[G]
       case expr: AssignmentExpr[S] => new AssignmentSem(expr).program[G]
       case expr: PushToStreamExpr[S] => new PushToStreamSem(expr).program[G]
       case expr: AliasExpr[S] => new AliasSem(expr).program[G]

semantics/src/main/scala/aqua/semantics/Semantics.scala

@@ -8,15 +8,11 @@ import aqua.raw.{Raw, RawContext, RawPart}
 import aqua.semantics.header.Picker
 import aqua.semantics.header.Picker.*
 import aqua.semantics.rules.abilities.{AbilitiesAlgebra, AbilitiesInterpreter, AbilitiesState}
-import aqua.semantics.rules.definitions.{
+import aqua.semantics.rules.definitions.{DefinitionsAlgebra, DefinitionsInterpreter}
-  DefinitionsAlgebra,
+import aqua.semantics.rules.locations.{DummyLocationsInterpreter, LocationsAlgebra}
-  DefinitionsInterpreter,
+import aqua.semantics.rules.names.{NamesAlgebra, NamesInterpreter}
-  DefinitionsState
+import aqua.semantics.rules.mangler.{ManglerAlgebra, ManglerInterpreter}
-}
+import aqua.semantics.rules.types.{TypesAlgebra, TypesInterpreter}
-import aqua.semantics.rules.locations.{DummyLocationsInterpreter, LocationsAlgebra, LocationsState}
-import aqua.semantics.rules.names.{NamesAlgebra, NamesInterpreter, NamesState}
-import aqua.semantics.rules.types.{TypesAlgebra, TypesInterpreter, TypesState}
-import aqua.semantics.rules.ValuesAlgebra
 import aqua.semantics.rules.errors.ReportErrors
 import aqua.semantics.rules.errors.ErrorsAlgebra
 import aqua.raw.ops.*
@@ -306,17 +302,19 @@ object RawSemantics extends Logging {
 
   type Interpreter[S[_], A] = State[CompilerState[S], A]
 
-  def transpile[S[_]](
+  def transpile[S[_]](ast: Ast[S])(using
-    ast: Ast[S]
+    LocationsAlgebra[S, Interpreter[S, *]]
-  )(implicit locations: LocationsAlgebra[S, Interpreter[S, *]]): Interpreter[S, Raw] = {
+  ): Interpreter[S, Raw] = {
 
-    implicit val typesInterpreter: TypesInterpreter[S, CompilerState[S]] =
+    given TypesAlgebra[S, Interpreter[S, *]] =
       new TypesInterpreter[S, CompilerState[S]]
-    implicit val abilitiesInterpreter: AbilitiesInterpreter[S, CompilerState[S]] =
+    given ManglerAlgebra[Interpreter[S, *]] =
+      new ManglerInterpreter[CompilerState[S]]
+    given AbilitiesAlgebra[S, Interpreter[S, *]] =
       new AbilitiesInterpreter[S, CompilerState[S]]
-    implicit val namesInterpreter: NamesInterpreter[S, CompilerState[S]] =
+    given NamesAlgebra[S, Interpreter[S, *]] =
       new NamesInterpreter[S, CompilerState[S]]
-    implicit val definitionsInterpreter: DefinitionsInterpreter[S, CompilerState[S]] =
+    given DefinitionsAlgebra[S, Interpreter[S, *]] =
       new DefinitionsInterpreter[S, CompilerState[S]]
 
     ast

semantics/src/main/scala/aqua/semantics/expr/AbilitySem.scala

@@ -1,9 +1,8 @@
 package aqua.semantics.expr
 
 import aqua.parser.expr.AbilityExpr
-import aqua.raw.{Raw, ServiceRaw, TypeRaw}
+import aqua.raw.{Raw, TypeRaw}
 import aqua.parser.lexer.{Name, NamedTypeToken}
-import aqua.raw.{Raw, ServiceRaw}
 import aqua.semantics.Prog
 import aqua.semantics.rules.ValuesAlgebra
 import aqua.semantics.rules.abilities.AbilitiesAlgebra
@@ -11,6 +10,7 @@ import aqua.semantics.rules.definitions.DefinitionsAlgebra
 import aqua.semantics.rules.names.NamesAlgebra
 import aqua.semantics.rules.types.TypesAlgebra
 import aqua.types.{AbilityType, ArrowType, Type}
+
 import cats.syntax.apply.*
 import cats.syntax.flatMap.*
 import cats.syntax.functor.*

semantics/src/main/scala/aqua/semantics/expr/ServiceSem.scala

@@ -8,49 +8,72 @@ import aqua.semantics.rules.abilities.AbilitiesAlgebra
 import aqua.semantics.rules.definitions.DefinitionsAlgebra
 import aqua.semantics.rules.names.NamesAlgebra
 import aqua.semantics.rules.types.TypesAlgebra
+
+import cats.data.EitherT
+import cats.syntax.either.*
+import cats.syntax.option.*
 import cats.syntax.apply.*
 import cats.syntax.flatMap.*
 import cats.syntax.functor.*
+import cats.syntax.traverse.*
+import cats.syntax.foldable.*
 import cats.syntax.applicative.*
 import cats.Monad
 
 class ServiceSem[S[_]](val expr: ServiceExpr[S]) extends AnyVal {
 
-  def program[Alg[_]: Monad](implicit
+  private def define[Alg[_]: Monad](using
     A: AbilitiesAlgebra[S, Alg],
     N: NamesAlgebra[S, Alg],
     T: TypesAlgebra[S, Alg],
     V: ValuesAlgebra[S, Alg],
     D: DefinitionsAlgebra[S, Alg]
-  ): Prog[Alg, Raw] =
+  ): EitherT[Alg, Raw, ServiceRaw] = for {
-    Prog.after(
+    arrows <- EitherT.fromOptionF(
-      _ =>
+      // TODO:  Move to purgeDefs here, allow not only arrows
-        D.purgeArrows(expr.name).flatMap {
+      //        from parsing, throw errors here
-          case Some(nel) =>
+      D.purgeArrows(expr.name),
-            val arrows = nel.map(kv => kv._1.value -> (kv._1, kv._2)).toNem
+      Raw.error("Service has no arrows")
-            for {
-              defaultId <- expr.id
-                .map(v => V.valueToRaw(v))
-                .getOrElse(None.pure[Alg])
-              defineResult <- A.defineService(
-                expr.name,
-                arrows,
-                defaultId
-              )
-              _ <- (expr.id zip defaultId)
-                .fold(().pure[Alg])(idV =>
-                  (V.ensureIsString(idV._1) >> A.setServiceId(expr.name, idV._1, idV._2)).map(_ =>
-                    ()
-                  )
-                )
-            } yield
-              if (defineResult) {
-                ServiceRaw(expr.name.value, arrows.map(_._2), defaultId)
-              } else Raw.empty("Service not created due to validation errors")
-
-          case None =>
-            Raw.error("Service has no arrows, fails").pure[Alg]
-
-        }
     )
+    arrowsByName = arrows.map { case (name, arrow) =>
+      name.value -> (name, arrow)
+    }.toNem
+    defaultId <- expr.id.traverse(id =>
+      EitherT.fromOptionF(
+        V.valueToStringRaw(id),
+        Raw.error("Failed to resolve default service id")
+      )
+    )
+    serviceType <- EitherT.fromOptionF(
+      T.defineServiceType(expr.name, arrowsByName.toSortedMap.toMap),
+      Raw.error("Failed to define service type")
+    )
+    arrowsDefs = arrows.map { case (name, _) => name.value -> name }.toNem
+    _ <- EitherT(
+      A.defineService(
+        expr.name,
+        arrowsDefs,
+        defaultId
+      ).map(defined =>
+        Raw
+          .error("Service not created due to validation errors")
+          .asLeft
+          .whenA(!defined)
+      )
+    )
+  } yield ServiceRaw(
+    expr.name.value,
+    serviceType,
+    defaultId
+  )
+
+  def program[Alg[_]: Monad](using
+    A: AbilitiesAlgebra[S, Alg],
+    N: NamesAlgebra[S, Alg],
+    T: TypesAlgebra[S, Alg],
+    V: ValuesAlgebra[S, Alg],
+    D: DefinitionsAlgebra[S, Alg]
+  ): Prog[Alg, Raw] = Prog.after_(
+    define.value.map(_.merge)
+  )
 }

semantics/src/main/scala/aqua/semantics/expr/func/AbilityIdSem.scala

@@ -1,30 +0,0 @@
-package aqua.semantics.expr.func
-
-import aqua.raw.Raw
-import aqua.raw.ops.AbilityIdTag
-import aqua.parser.expr.func.AbilityIdExpr
-import aqua.semantics.Prog
-import aqua.semantics.rules.ValuesAlgebra
-import aqua.semantics.rules.abilities.AbilitiesAlgebra
-import cats.Monad
-import cats.syntax.applicative.*
-import cats.syntax.flatMap.*
-import cats.syntax.functor.*
-
-class AbilityIdSem[S[_]](val expr: AbilityIdExpr[S]) extends AnyVal {
-
-  def program[Alg[_]: Monad](implicit
-    A: AbilitiesAlgebra[S, Alg],
-    V: ValuesAlgebra[S, Alg]
-  ): Prog[Alg, Raw] =
-    V.ensureIsString(expr.id) >> V.valueToRaw(
-      expr.id
-    ) >>= {
-      case Some(id) =>
-        A.setServiceId(expr.ability, expr.id, id) as (AbilityIdTag(
-          id,
-          expr.ability.value
-        ).funcOpLeaf: Raw)
-      case _ => Raw.error("Cannot resolve ability ID").pure[Alg]
-    }
-}

semantics/src/main/scala/aqua/semantics/expr/func/ArrowSem.scala

@@ -13,11 +13,13 @@ import aqua.semantics.rules.abilities.AbilitiesAlgebra
 import aqua.semantics.rules.locations.LocationsAlgebra
 import aqua.semantics.rules.names.NamesAlgebra
 import aqua.semantics.rules.types.TypesAlgebra
-import aqua.types.{ArrayType, ArrowType, CanonStreamType, ProductType, StreamType, Type}
+import aqua.types.*
 
 import cats.Eval
 import cats.data.{Chain, NonEmptyList}
 import cats.free.{Cofree, Free}
+import cats.data.OptionT
+import cats.syntax.show.*
 import cats.syntax.applicative.*
 import cats.syntax.apply.*
 import cats.syntax.foldable.*
@@ -64,16 +66,15 @@ class ArrowSem[S[_]](val expr: ArrowExpr[S]) extends AnyVal {
     res = bodyGen match {
       case FuncOp(bodyModel) =>
         // TODO: wrap with local on...via...
-
         val retsAndArgs = retValues zip funcArrow.codomain.toList
 
-        val argNames = funcArrow.domain.labelledData.map { case (name, _) => name }
+        val dataArgsNames = funcArrow.domain.labelledData.map { case (name, _) => name }
         val streamsThatReturnAsStreams = retsAndArgs.collect {
           case (VarRaw(n, StreamType(_)), StreamType(_)) => n
         }.toSet
 
         // Remove arguments, and values returned as streams
-        val localStreams = streamsInScope -- argNames -- streamsThatReturnAsStreams
+        val localStreams = streamsInScope -- dataArgsNames -- streamsThatReturnAsStreams
 
         // process stream that returns as not streams and all Apply*Raw
         val (bodyRets, retVals) = retsAndArgs.mapWithIndex {

semantics/src/main/scala/aqua/semantics/expr/func/OnSem.scala

@@ -10,7 +10,9 @@ import aqua.semantics.rules.ValuesAlgebra
 import aqua.semantics.rules.abilities.AbilitiesAlgebra
 import aqua.semantics.rules.types.TypesAlgebra
 import aqua.types.{BoxType, OptionType, ScalarType}
+
 import cats.data.Chain
+import cats.data.OptionT
 import cats.syntax.applicative.*
 import cats.syntax.apply.*
 import cats.syntax.flatMap.*
@@ -49,24 +51,25 @@ class OnSem[S[_]](val expr: OnExpr[S]) extends AnyVal {
 
 object OnSem {
 
-  def beforeOn[S[_], Alg[_]: Monad](peerId: ValueToken[S], via: List[ValueToken[S]])(implicit
+  def beforeOn[S[_], Alg[_]: Monad](
+    peerId: ValueToken[S],
+    via: List[ValueToken[S]]
+  )(using
     V: ValuesAlgebra[S, Alg],
     T: TypesAlgebra[S, Alg],
     A: AbilitiesAlgebra[S, Alg]
   ): Alg[List[ValueRaw]] =
+    // TODO: Remove ensureIsString, use valueToStringRaw
     V.ensureIsString(peerId) *> via
       .traverse(v =>
-        V.valueToRaw(v).flatTap {
+        OptionT(V.valueToRaw(v)).filterF { vm =>
-          case Some(vm) =>
+          val expectedType = vm.`type` match {
-            vm.`type` match {
+            case _: BoxType => OptionType(ScalarType.string)
-              case _: BoxType =>
+            case _ => ScalarType.string
-                T.ensureTypeMatches(v, OptionType(ScalarType.string), vm.`type`)
+          }
-              case _ =>
+
-                T.ensureTypeMatches(v, ScalarType.string, vm.`type`)
+          T.ensureTypeMatches(v, expectedType, vm.`type`)
-            }
-          case None => false.pure[Alg]
         }
       )
-      .map(_.flatten)
+      .getOrElse(List.empty)
-
 }

semantics/src/main/scala/aqua/semantics/expr/func/ServiceIdSem.scala

@@ -0,0 +1,49 @@
+package aqua.semantics.expr.func
+
+import aqua.raw.Raw
+import aqua.raw.ops.ServiceIdTag
+import aqua.parser.expr.func.ServiceIdExpr
+import aqua.semantics.Prog
+import aqua.semantics.rules.ValuesAlgebra
+import aqua.semantics.rules.abilities.AbilitiesAlgebra
+import aqua.semantics.rules.types.TypesAlgebra
+import aqua.semantics.rules.names.NamesAlgebra
+
+import cats.Monad
+import cats.data.EitherT
+import cats.syntax.either.*
+import cats.syntax.applicative.*
+import cats.syntax.flatMap.*
+import cats.syntax.functor.*
+
+class ServiceIdSem[S[_]](val expr: ServiceIdExpr[S]) extends AnyVal {
+
+  def program[Alg[_]: Monad](using
+    A: AbilitiesAlgebra[S, Alg],
+    V: ValuesAlgebra[S, Alg],
+    N: NamesAlgebra[S, Alg],
+    T: TypesAlgebra[S, Alg]
+  ): Prog[Alg, Raw] = (
+    for {
+      id <- EitherT.fromOptionF(
+        V.valueToStringRaw(expr.id),
+        Raw.error("Can not resolve service ID")
+      )
+      serviceType <- EitherT.fromOptionF(
+        T.resolveServiceType(expr.service),
+        Raw.error("Can not resolve service type")
+      )
+      name <- EitherT.fromOptionF(
+        A.renameService(expr.service),
+        Raw.error("Can not set service ID")
+      )
+      _ <- EitherT.liftF(
+        N.derive(
+          expr.service.asName.rename(name),
+          serviceType,
+          id.varNames
+        )
+      )
+    } yield ServiceIdTag(id, serviceType, name).funcOpLeaf
+  ).value.map(_.merge)
+}

semantics/src/main/scala/aqua/semantics/rules/ValuesAlgebra.scala

@@ -11,6 +11,7 @@ import aqua.semantics.rules.errors.ErrorsAlgebra
 import aqua.types.*
 
 import cats.Monad
+import cats.data.OptionT
 import cats.data.Chain
 import cats.syntax.applicative.*
 import cats.syntax.apply.*
@@ -33,23 +34,6 @@ class ValuesAlgebra[S[_], Alg[_]: Monad](using
   A: AbilitiesAlgebra[S, Alg]
 ) extends Logging {
 
-  def ensureIsString(v: ValueToken[S]): Alg[Boolean] =
-    ensureTypeMatches(v, LiteralType.string)
-
-  def ensureTypeMatches(v: ValueToken[S], expected: Type): Alg[Boolean] =
-    resolveType(v).flatMap {
-      case Some(vt) =>
-        T.ensureTypeMatches(
-          v,
-          expected,
-          vt
-        )
-      case None => false.pure[Alg]
-    }
-
-  def resolveType(v: ValueToken[S]): Alg[Option[Type]] =
-    valueToRaw(v).map(_.map(_.`type`))
-
   private def resolveSingleProperty(rootType: Type, op: PropertyOp[S]): Alg[Option[PropertyRaw]] =
     op match {
       case op: IntoField[S] =>
@@ -83,11 +67,20 @@ class ValuesAlgebra[S[_], Alg[_]: Monad](using
         LiteralRaw(l.value, t).some.pure[Alg]
 
       case VarToken(name) =>
-        N.read(name).flatMap {
+        N.read(name, mustBeDefined = false).flatMap {
           case Some(t) =>
-            VarRaw(name.value, t).some.pure[Alg]
+            VarRaw(name.value, t).some.pure
           case None =>
-            None.pure[Alg]
+            (for {
+              t <- OptionT(
+                T.getType(name.value)
+              ).collect { case st: ServiceType => st }
+                // A hack to report name error, better to refactor
+                .flatTapNone(N.read(name))
+              rename <- OptionT(
+                A.getServiceRename(name.asTypeToken)
+              )
+            } yield VarRaw(rename, t)).value
         }
 
       case prop @ PropertyToken(value, properties) =>
@@ -107,35 +100,30 @@ class ValuesAlgebra[S[_], Alg[_]: Monad](using
         )(valueToRaw)
 
       case dvt @ NamedValueToken(typeName, fields) =>
-        T.resolveType(typeName).flatMap {
+        (for {
-          case Some(resolvedType) =>
+          resolvedType <- OptionT(T.resolveType(typeName))
-            for {
+          fieldsGiven <- fields.traverse(value => OptionT(valueToRaw(value)))
-              fieldsRawOp: NonEmptyMap[String, Option[ValueRaw]] <- fields.traverse(valueToRaw)
+          fieldsGivenTypes = fieldsGiven.map(_.`type`)
-              fieldsRaw: List[(String, ValueRaw)] = fieldsRawOp.toSortedMap.toList.collect {
+          generated <- OptionT.fromOption(
-                case (n, Some(vr)) => n -> vr
+            resolvedType match {
-              }
+              case struct: StructType =>
-              rawFields = NonEmptyMap.fromMap(SortedMap.from(fieldsRaw))
+                (
-              typeFromFieldsWithData = rawFields
+                  struct.copy(fields = fieldsGivenTypes),
-                .map(rf =>
+                  MakeStructRaw(fieldsGiven, struct)
-                  resolvedType match {
+                ).some
-                    case struct @ StructType(_, _) =>
+              case ability: AbilityType =>
-                      (
+                (
-                        StructType(typeName.value, rf.map(_.`type`)),
+                  ability.copy(fields = fieldsGivenTypes),
-                        Some(MakeStructRaw(rf, struct))
+                  AbilityRaw(fieldsGiven, ability)
-                      )
+                ).some
-                    case scope @ AbilityType(_, _) =>
+              case _ => none
-                      (
+            }
-                        AbilityType(typeName.value, rf.map(_.`type`)),
+          )
-                        Some(AbilityRaw(rf, scope))
+          (genType, genData) = generated
-                      )
+          data <- OptionT.whenM(
-                  }
+            T.ensureTypeMatches(dvt, resolvedType, genType)
-                )
+          )(genData.pure)
-                .getOrElse(BottomType -> None)
+        } yield data).value
-              (typeFromFields, data) = typeFromFieldsWithData
-              isTypesCompatible <- T.ensureTypeMatches(dvt, resolvedType, typeFromFields)
-            } yield data.filter(_ => isTypesCompatible)
-          case _ => None.pure[Alg]
-        }
 
       case ct @ CollectionToken(_, values) =>
         for {
@@ -295,15 +283,15 @@ class ValuesAlgebra[S[_], Alg[_]: Monad](using
                 } yield Option.when(
                   leftChecked.isDefined && rightChecked.isDefined
                 )(
-                  CallArrowRaw(
+                  CallArrowRaw.service(
-                    ability = Some(id),
+                    abilityName = id,
-                    name = fn,
+                    serviceId = LiteralRaw.quote(id),
-                    arguments = leftRaw :: rightRaw :: Nil,
+                    funcName = fn,
                     baseType = ArrowType(
                       ProductType(lType :: rType :: Nil),
                       ProductType(resType :: Nil)
                     ),
-                    serviceId = Some(LiteralRaw.quote(id))
+                    arguments = leftRaw :: rightRaw :: Nil
                   )
                 )
 
@@ -321,9 +309,24 @@ class ValuesAlgebra[S[_], Alg[_]: Monad](using
       }
     )
 
+  def valueToTypedRaw(v: ValueToken[S], expectedType: Type): Alg[Option[ValueRaw]] =
+    OptionT(valueToRaw(v))
+      .flatMap(raw =>
+        OptionT.whenM(
+          T.ensureTypeMatches(v, expectedType, raw.`type`)
+        )(raw.pure)
+      )
+      .value
+
+  def valueToStringRaw(v: ValueToken[S]): Alg[Option[ValueRaw]] =
+    valueToTypedRaw(v, LiteralType.string)
+
+  def ensureIsString(v: ValueToken[S]): Alg[Boolean] =
+    valueToStringRaw(v).map(_.isDefined)
+
   private def callArrowFromAbility(
     ab: Name[S],
-    at: AbilityType,
+    at: NamedType,
     funcName: Name[S]
   ): Option[CallArrowRaw] = at.arrows
     .get(funcName.value)
@@ -351,24 +354,23 @@ class ValuesAlgebra[S[_], Alg[_]: Monad](using
           )
       )(ab =>
         N.read(ab.asName, mustBeDefined = false).flatMap {
-          case Some(at: AbilityType) =>
+          case Some(nt: (AbilityType | ServiceType)) =>
-            callArrowFromAbility(ab.asName, at, callArrow.funcName).pure
+            callArrowFromAbility(ab.asName, nt, callArrow.funcName).pure
           case _ =>
             T.getType(ab.value).flatMap {
-              case Some(at: AbilityType) =>
+              case Some(st: ServiceType) =>
-                callArrowFromAbility(ab.asName, at, callArrow.funcName).pure
+                OptionT(A.getServiceRename(ab))
+                  .subflatMap(rename =>
+                    callArrowFromAbility(
+                      ab.asName.rename(rename),
+                      st,
+                      callArrow.funcName
+                    )
+                  )
+                  .value
               case _ =>
-                (A.getArrow(ab, callArrow.funcName), A.getServiceId(ab)).mapN {
+                A.getArrow(ab, callArrow.funcName).map {
-                  case (Some(at), Right(sid)) =>
+                  case Some(at) =>
-                    CallArrowRaw
-                      .service(
-                        abilityName = ab.value,
-                        serviceId = sid,
-                        funcName = callArrow.funcName.value,
-                        baseType = at
-                      )
-                      .some
-                  case (Some(at), Left(true)) =>
                     CallArrowRaw
                       .ability(
                         abilityName = ab.value,

semantics/src/main/scala/aqua/semantics/rules/abilities/AbilitiesAlgebra.scala

@@ -2,7 +2,8 @@ package aqua.semantics.rules.abilities
 
 import aqua.parser.lexer.{Name, NamedTypeToken, Token, ValueToken}
 import aqua.raw.value.ValueRaw
-import aqua.types.ArrowType
+import aqua.types.{ArrowType, ServiceType}
+
 import cats.InjectK
 import cats.data.{NonEmptyList, NonEmptyMap}
 
@@ -10,15 +11,15 @@ trait AbilitiesAlgebra[S[_], Alg[_]] {
 
   def defineService(
     name: NamedTypeToken[S],
-    arrows: NonEmptyMap[String, (Name[S], ArrowType)],
+    arrowDefs: NonEmptyMap[String, Name[S]],
     defaultId: Option[ValueRaw]
   ): Alg[Boolean]
 
   def getArrow(name: NamedTypeToken[S], arrow: Name[S]): Alg[Option[ArrowType]]
 
-  def setServiceId(name: NamedTypeToken[S], id: ValueToken[S], vm: ValueRaw): Alg[Boolean]
+  def renameService(name: NamedTypeToken[S]): Alg[Option[String]]
 
-  def getServiceId(name: NamedTypeToken[S]): Alg[Either[Boolean, ValueRaw]]
+  def getServiceRename(name: NamedTypeToken[S]): Alg[Option[String]]
 
   def beginScope(token: Token[S]): Alg[Unit]
 

semantics/src/main/scala/aqua/semantics/rules/abilities/AbilitiesInterpreter.scala

@@ -5,27 +5,31 @@ import aqua.raw.value.ValueRaw
 import aqua.raw.{RawContext, ServiceRaw}
 import aqua.semantics.Levenshtein
 import aqua.semantics.rules.errors.ReportErrors
+import aqua.semantics.rules.mangler.ManglerAlgebra
 import aqua.semantics.rules.locations.LocationsAlgebra
 import aqua.semantics.rules.{abilities, StackInterpreter}
-import aqua.types.ArrowType
+import aqua.types.{ArrowType, ServiceType}
 
 import cats.data.{NonEmptyMap, State}
 import cats.syntax.functor.*
+import cats.syntax.apply.*
 import cats.syntax.foldable.*
 import cats.syntax.traverse.*
 import cats.syntax.applicative.*
+import cats.syntax.option.*
 import monocle.Lens
 import monocle.macros.GenLens
 
-class AbilitiesInterpreter[S[_], X](implicit
+class AbilitiesInterpreter[S[_], X](using
   lens: Lens[X, AbilitiesState[S]],
   error: ReportErrors[S, X],
+  mangler: ManglerAlgebra[State[X, *]],
   locations: LocationsAlgebra[S, State[X, *]]
 ) extends AbilitiesAlgebra[S, State[X, *]] {
 
   type SX[A] = State[X, A]
 
-  val stackInt = new StackInterpreter[S, X, AbilitiesState[S], AbilitiesState.Frame[S]](
+  private val stackInt = new StackInterpreter[S, X, AbilitiesState[S], AbilitiesState.Frame[S]](
     GenLens[AbilitiesState[S]](_.stack)
   )
 
@@ -33,11 +37,11 @@ class AbilitiesInterpreter[S[_], X](implicit
 
   override def defineService(
     name: NamedTypeToken[S],
-    arrows: NonEmptyMap[String, (Name[S], ArrowType)],
+    arrowDefs: NonEmptyMap[String, Name[S]],
     defaultId: Option[ValueRaw]
   ): SX[Boolean] =
-    getService(name.value).flatMap {
+    serviceExists(name.value).flatMap {
-      case Some(_) =>
+      case true =>
         getState
           .map(_.definitions.get(name.value).exists(_ == name))
           .flatMap(exists =>
@@ -47,23 +51,14 @@ class AbilitiesInterpreter[S[_], X](implicit
             ).whenA(!exists)
           )
           .as(false)
-      case None =>
+      case false =>
         for {
-          _ <- arrows.toNel.traverse_ { case (_, (n, arr)) =>
+          _ <- modify(_.defineService(name, defaultId))
-            report(n, "Service functions cannot have multiple results")
+          // TODO: Is it used?
-              .whenA(arr.codomain.length > 1)
-          }
-          _ <- modify(s =>
-            s.copy(
-              services = s.services
-                .updated(name.value, ServiceRaw(name.value, arrows.map(_._2), defaultId)),
-              definitions = s.definitions.updated(name.value, name)
-            )
-          )
           _ <- locations.addTokenWithFields(
             name.value,
             name,
-            arrows.toNel.toList.map(t => t._1 -> t._2._1)
+            arrowDefs.toNel.toList
           )
         } yield true
     }
@@ -74,83 +69,50 @@ class AbilitiesInterpreter[S[_], X](implicit
   }
 
   override def getArrow(name: NamedTypeToken[S], arrow: Name[S]): SX[Option[ArrowType]] =
-    getService(name.value).map(_.map(_.arrows)).flatMap {
+    getAbility(name.value).flatMap {
-      case Some(arrows) =>
+      case Some(abCtx) =>
-        arrows(arrow.value)
+        abCtx.funcs
+          .get(arrow.value)
           .fold(
             report(
               arrow,
               Levenshtein.genMessage(
-                s"Service is found, but arrow '${arrow.value}' isn't found in scope",
+                s"Ability is found, but arrow '${arrow.value}' isn't found in scope",
                 arrow.value,
-                arrows.value.keys.toNonEmptyList.toList
+                abCtx.funcs.keys.toList
               )
-            ).as(Option.empty[ArrowType])
+            ).as(none)
-          )(a => addServiceArrowLocation(name, arrow).as(Some(a)))
+          ) { fn =>
-      case None =>
+            // TODO: add name and arrow separately
-        getAbility(name.value).flatMap {
+            // TODO: find tokens somewhere
-          case Some(abCtx) =>
+            addServiceArrowLocation(name, arrow).as(fn.arrow.`type`.some)
-            abCtx.funcs
-              .get(arrow.value)
-              .fold(
-                report(
-                  arrow,
-                  Levenshtein.genMessage(
-                    s"Ability is found, but arrow '${arrow.value}' isn't found in scope",
-                    arrow.value,
-                    abCtx.funcs.keys.toList
-                  )
-                ).as(Option.empty[ArrowType])
-              ) { fn =>
-                // TODO: add name and arrow separately
-                // TODO: find tokens somewhere
-                addServiceArrowLocation(name, arrow).as(Some(fn.arrow.`type`))
-              }
-          case None =>
-            report(name, "Ability with this name is undefined").as(Option.empty[ArrowType])
-        }
-    }
-
-  override def setServiceId(name: NamedTypeToken[S], id: ValueToken[S], vm: ValueRaw): SX[Boolean] =
-    getService(name.value).flatMap {
-      case Some(_) =>
-        mapStackHeadM(
-          modify(st => st.copy(rootServiceIds = st.rootServiceIds.updated(name.value, id -> vm)))
-            .as(true)
-        )(h => (h.copy(serviceIds = h.serviceIds.updated(name.value, id -> vm)) -> true).pure)
-      case None =>
-        report(name, "Service with this name is not registered, can't set its ID").as(false)
-    }
-
-  override def getServiceId(name: NamedTypeToken[S]): SX[Either[Boolean, ValueRaw]] =
-    getService(name.value).flatMap {
-      case Some(_) =>
-        getState.flatMap(st =>
-          st.stack
-            .flatMap(_.serviceIds.get(name.value).map(_._2))
-            .headOption orElse st.rootServiceIds
-            .get(
-              name.value
-            )
-            .map(_._2) orElse st.services.get(name.value).flatMap(_.defaultId) match {
-            case None =>
-              report(
-                name,
-                s"Service ID unresolved, use `${name.value} id` expression to set it"
-              )
-                .as(Left[Boolean, ValueRaw](false))
-
-            case Some(v) => State.pure(Right(v))
           }
-        )
       case None =>
-        getAbility(name.value).flatMap {
+        report(name, "Ability with this name is undefined").as(none)
-          case Some(_) => State.pure(Left[Boolean, ValueRaw](true))
+    }
-          case None =>
+
-            report(name, "Ability with this name is undefined").as(
+  override def renameService(name: NamedTypeToken[S]): SX[Option[String]] =
-              Left[Boolean, ValueRaw](false)
+    serviceExists(name.value).flatMap {
-            )
+      case true =>
-        }
+        mapStackHeadM(
+          name.value.pure
+        )(h =>
+          mangler
+            .rename(name.value)
+            .map(newName => h.setServiceRename(name.value, newName) -> newName)
+        ).map(_.some)
+      case false =>
+        report(name, "Service with this name is not registered").as(none)
+    }
+
+  override def getServiceRename(name: NamedTypeToken[S]): State[X, Option[String]] =
+    (
+      serviceExists(name.value),
+      getState.map(_.getServiceRename(name.value))
+    ).flatMapN {
+      case (true, Some(rename)) => rename.some.pure
+      case (false, _) => report(name, "Service with this name is undefined").as(none)
+      case (_, None) => report(name, "Service ID is undefined").as(none)
     }
 
   override def beginScope(token: Token[S]): SX[Unit] =
@@ -158,8 +120,8 @@ class AbilitiesInterpreter[S[_], X](implicit
 
   override def endScope(): SX[Unit] = stackInt.endScope
 
-  private def getService(name: String): SX[Option[ServiceRaw]] =
+  private def serviceExists(name: String): SX[Boolean] =
-    getState.map(_.services.get(name))
+    getState.map(_.services(name))
 
   private def getAbility(name: String): SX[Option[RawContext]] =
     getState.map(_.abilities.get(name))

semantics/src/main/scala/aqua/semantics/rules/abilities/AbilitiesState.scala

@@ -4,54 +4,81 @@ import aqua.raw.{RawContext, ServiceRaw}
 import aqua.raw.value.ValueRaw
 import aqua.parser.lexer.{Name, NamedTypeToken, Token, ValueToken}
 import aqua.types.ArrowType
+
 import cats.Monoid
+import cats.syntax.foldable.*
+import cats.syntax.functor.*
 import cats.data.NonEmptyList
+import aqua.parser.lexer.Token.name
 
 case class AbilitiesState[S[_]](
   stack: List[AbilitiesState.Frame[S]] = Nil,
-  services: Map[String, ServiceRaw] = Map.empty,
+  services: Set[String] = Set.empty,
   abilities: Map[String, RawContext] = Map.empty,
-  rootServiceIds: Map[String, (ValueToken[S], ValueRaw)] =
+  rootServiceIds: Map[String, ValueRaw] = Map(),
-    Map.empty[String, (ValueToken[S], ValueRaw)],
+  definitions: Map[String, NamedTypeToken[S]] = Map()
-  definitions: Map[String, NamedTypeToken[S]] = Map.empty[String, NamedTypeToken[S]]
 ) {
 
-  def purgeArrows: Option[(NonEmptyList[(Name[S], ArrowType)], AbilitiesState[S])] =
+  def defineService(name: NamedTypeToken[S], defaultId: Option[ValueRaw]): AbilitiesState[S] =
-    stack match {
+    copy(
-      case sc :: tail =>
+      services = services + name.value,
-        NonEmptyList
+      definitions = definitions.updated(name.value, name),
-          .fromList(sc.arrows.values.toList)
+      rootServiceIds = rootServiceIds ++ defaultId.map(name.value -> _)
-          .map(_ -> copy[S](sc.copy(arrows = Map.empty) :: tail))
+    )
-      case _ => None
+
-    }
+  def getServiceRename(name: String): Option[String] =
+    stack.collectFirstSome(_.getServiceRename(name)) orElse
+      // Suppose that services without id
+      // resolved in scope are not renamed
+      rootServiceIds.get(name).as(name)
+
 }
 
 object AbilitiesState {
 
   case class Frame[S[_]](
     token: Token[S],
-    arrows: Map[String, (Name[S], ArrowType)] = Map.empty[String, (Name[S], ArrowType)],
+    services: Map[String, Frame.ServiceState] = Map()
-    serviceIds: Map[String, (ValueToken[S], ValueRaw)] =
+  ) {
-      Map.empty[String, (ValueToken[S], ValueRaw)]
-  )
 
-  implicit def abilitiesStateMonoid[S[_]]: Monoid[AbilitiesState[S]] =
+    def setServiceRename(name: String, rename: String): Frame[S] =
-    new Monoid[AbilitiesState[S]] {
+      copy(services =
-      override def empty: AbilitiesState[S] = AbilitiesState()
+        services.updated(
-
+          name,
-      override def combine(x: AbilitiesState[S], y: AbilitiesState[S]): AbilitiesState[S] =
+          Frame.ServiceState(rename)
-        AbilitiesState(
-          Nil,
-          x.services ++ y.services,
-          x.abilities ++ y.abilities,
-          x.rootServiceIds ++ y.rootServiceIds,
-          x.definitions ++ y.definitions
         )
-    }
+      )
+
+    def getServiceRename(name: String): Option[String] =
+      services.get(name).map(_.rename)
+  }
+
+  object Frame {
+
+    final case class ServiceState(
+      rename: String
+    )
+  }
+
+  given [S[_]]: Monoid[AbilitiesState[S]] with {
+    override def empty: AbilitiesState[S] = AbilitiesState()
+
+    override def combine(x: AbilitiesState[S], y: AbilitiesState[S]): AbilitiesState[S] =
+      AbilitiesState(
+        Nil,
+        x.services ++ y.services,
+        x.abilities ++ y.abilities,
+        x.rootServiceIds ++ y.rootServiceIds,
+        x.definitions ++ y.definitions
+      )
+  }
 
   def init[S[_]](context: RawContext): AbilitiesState[S] =
     AbilitiesState(
-      services = context.allServices,
+      services = context.allServices.keySet,
+      rootServiceIds = context.allServices.flatMap { case (name, service) =>
+        service.defaultId.map(name -> _)
+      },
       abilities = context.abilities // TODO is it the right way to collect abilities? Why?
     )
 }

semantics/src/main/scala/aqua/semantics/rules/mangler/ManglerAlgebra.scala

@@ -0,0 +1,5 @@
+package aqua.semantics.rules.mangler
+
+trait ManglerAlgebra[Alg[_]] {
+  def rename(name: String): Alg[String]
+}

semantics/src/main/scala/aqua/semantics/rules/mangler/ManglerInterpreter.scala

@@ -0,0 +1,27 @@
+package aqua.semantics.rules.mangler
+
+import cats.data.State
+import monocle.Lens
+import monocle.macros.GenLens
+
+class ManglerInterpreter[X](using
+  lens: Lens[X, ManglerState]
+) extends ManglerAlgebra[State[X, *]] {
+
+  override def rename(name: String): State[X, String] =
+    for {
+      s <- get
+      newName = LazyList
+        .from(0)
+        .map(i => s"$name-$i")
+        .dropWhile(s.isForbidden)
+        .head
+      _ <- modify(_.forbid(newName))
+    } yield newName
+
+  private lazy val get: State[X, ManglerState] =
+    State.get[X].map(lens.get)
+
+  private def modify(f: ManglerState => ManglerState): State[X, Unit] =
+    State.modify[X](lens.modify(f))
+}

semantics/src/main/scala/aqua/semantics/rules/mangler/ManglerState.scala

@@ -0,0 +1,24 @@
+package aqua.semantics.rules.mangler
+
+import cats.kernel.Monoid
+
+final case class ManglerState(
+  forbidden: Set[String] = Set.empty
+) {
+
+  def isForbidden(name: String): Boolean =
+    forbidden.contains(name)
+
+  def forbid(name: String): ManglerState =
+    copy(forbidden = forbidden + name)
+}
+
+object ManglerState {
+
+  given Monoid[ManglerState] with {
+    override val empty: ManglerState = ManglerState()
+
+    override def combine(x: ManglerState, y: ManglerState): ManglerState =
+      ManglerState(forbidden = x.forbidden ++ y.forbidden)
+  }
+}

semantics/src/main/scala/aqua/semantics/rules/types/TypesAlgebra.scala

@@ -2,7 +2,7 @@ package aqua.semantics.rules.types
 
 import aqua.parser.lexer.*
 import aqua.raw.value.{PropertyRaw, ValueRaw}
-import aqua.types.{AbilityType, ArrowType, NamedType, StructType, Type}
+import aqua.types.*
 
 import cats.data.NonEmptyMap
 import cats.data.NonEmptyList
@@ -15,11 +15,18 @@ trait TypesAlgebra[S[_], Alg[_]] {
 
   def resolveArrowDef(arrowDef: ArrowTypeToken[S]): Alg[Option[ArrowType]]
 
+  def resolveServiceType(name: NamedTypeToken[S]): Alg[Option[ServiceType]]
+
   def defineAbilityType(
     name: NamedTypeToken[S],
     fields: Map[String, (Name[S], Type)]
   ): Alg[Option[AbilityType]]
 
+  def defineServiceType(
+    name: NamedTypeToken[S],
+    fields: Map[String, (Name[S], Type)]
+  ): Alg[Option[ServiceType]]
+
   def defineStructType(
     name: NamedTypeToken[S],
     fields: Map[String, (Name[S], Type)]

semantics/src/main/scala/aqua/semantics/rules/types/TypesInterpreter.scala

@@ -13,16 +13,17 @@ import aqua.raw.value.{
 import aqua.semantics.rules.locations.LocationsAlgebra
 import aqua.semantics.rules.StackInterpreter
 import aqua.semantics.rules.errors.ReportErrors
+import aqua.semantics.rules.types.TypesStateHelper.{TypeResolution, TypeResolutionError}
 import aqua.types.*
 
 import cats.data.Validated.{Invalid, Valid}
-import cats.data.{Chain, NonEmptyList, NonEmptyMap, State}
+import cats.data.{Chain, NonEmptyList, NonEmptyMap, OptionT, State}
-import cats.instances.list.*
 import cats.syntax.applicative.*
 import cats.syntax.apply.*
 import cats.syntax.flatMap.*
 import cats.syntax.functor.*
 import cats.syntax.traverse.*
+import cats.syntax.foldable.*
 import cats.{~>, Applicative}
 import cats.syntax.option.*
 import monocle.Lens
@@ -44,18 +45,12 @@ class TypesInterpreter[S[_], X](implicit
 
   type ST[A] = State[X, A]
 
-  val resolver: (TypesState[S], NamedTypeToken[S]) => Option[
-    (Type, List[(Token[S], NamedTypeToken[S])])
-  ] = { (state, ctt) =>
-    state.strict.get(ctt.value).map(t => (t, state.definitions.get(ctt.value).toList.map(ctt -> _)))
-  }
-
   override def getType(name: String): State[X, Option[Type]] =
     getState.map(st => st.strict.get(name))
 
   override def resolveType(token: TypeToken[S]): State[X, Option[Type]] =
-    getState.map(st => TypesStateHelper.resolveTypeToken(token, st, resolver)).flatMap {
+    getState.map(TypesStateHelper.resolveTypeToken(token)).flatMap {
-      case Some((typ, tokens)) =>
+      case Some(TypeResolution(typ, tokens)) =>
         val tokensLocs = tokens.map { case (t, n) => n.value -> t }
         locations.pointLocations(tokensLocs).as(typ.some)
       case None =>
@@ -64,88 +59,111 @@ class TypesInterpreter[S[_], X](implicit
     }
 
   override def resolveArrowDef(arrowDef: ArrowTypeToken[S]): State[X, Option[ArrowType]] =
-    getState.map(st => TypesStateHelper.resolveArrowDef(arrowDef, st, resolver)).flatMap {
+    getState.map(TypesStateHelper.resolveArrowDef(arrowDef)).flatMap {
-      case Valid(t) =>
+      case Valid(TypeResolution(tt, tokens)) =>
-        val (tt, tokens) = t
+        val tokensLocs = tokens.map { case (t, n) => n.value -> t }
-        val tokensLocs = tokens.map { case (t, n) =>
+        locations.pointLocations(tokensLocs).as(tt.some)
-          n.value -> t
-        }
-        locations.pointLocations(tokensLocs).map(_ => Some(tt))
       case Invalid(errs) =>
-        errs
+        errs.traverse_ { case TypeResolutionError(token, hint) =>
-          .foldLeft[ST[Option[ArrowType]]](State.pure(None)) { case (n, (tkn, hint)) =>
+          report(token, hint)
-            report(tkn, hint) >> n
+        }.as(none)
-          }
+    }
+
+  override def resolveServiceType(name: NamedTypeToken[S]): State[X, Option[ServiceType]] =
+    resolveType(name).flatMap {
+      case Some(serviceType: ServiceType) =>
+        serviceType.some.pure
+      case Some(t) =>
+        report(name, s"Type `$t` is not a service").as(none)
+      case None =>
+        report(name, s"Type `${name.value}` is not defined").as(none)
     }
 
   override def defineAbilityType(
     name: NamedTypeToken[S],
     fields: Map[String, (Name[S], Type)]
   ): State[X, Option[AbilityType]] =
-    getState.map(_.definitions.get(name.value)).flatMap {
+    ensureNameNotDefined(name.value, name, ifDefined = none) {
-      case Some(_) => report(name, s"Ability `${name.value}` was already defined").as(none)
+      val types = fields.view.mapValues { case (_, t) => t }.toMap
-      case None =>
+      NonEmptyMap
-        val types = fields.view.mapValues { case (_, t) => t }.toMap
+        .fromMap(SortedMap.from(types))
-        NonEmptyMap
+        .fold(report(name, s"Ability `${name.value}` has no fields").as(none))(nonEmptyFields =>
-          .fromMap(SortedMap.from(types))
+          val `type` = AbilityType(name.value, nonEmptyFields)
-          .fold(report(name, s"Ability `${name.value}` has no fields").as(none))(nonEmptyFields =>
+
-            val `type` = AbilityType(name.value, nonEmptyFields)
+          modify(_.defineType(name, `type`)).as(`type`.some)
-            modify { st =>
+        )
-              st.copy(
-                strict = st.strict.updated(name.value, `type`),
-                definitions = st.definitions.updated(name.value, name)
-              )
-            }.as(`type`.some)
-          )
     }
 
+  override def defineServiceType(
+    name: NamedTypeToken[S],
+    fields: Map[String, (Name[S], Type)]
+  ): State[X, Option[ServiceType]] =
+    ensureNameNotDefined(name.value, name, ifDefined = none)(
+      fields.toList.traverse {
+        case (field, (fieldName, t: ArrowType)) =>
+          OptionT
+            .when(t.codomain.length <= 1)(field -> t)
+            .flatTapNone(
+              report(fieldName, "Service functions cannot have multiple results")
+            )
+        case (field, (fieldName, t)) =>
+          OptionT(
+            report(
+              fieldName,
+              s"Field '$field' has unacceptable for service field type '$t'"
+            ).as(none)
+          )
+      }.flatMapF(arrows =>
+        NonEmptyMap
+          .fromMap(SortedMap.from(arrows))
+          .fold(
+            report(name, s"Service `${name.value}` has no fields").as(none)
+          )(_.some.pure)
+      ).semiflatMap(nonEmptyArrows =>
+        val `type` = ServiceType(name.value, nonEmptyArrows)
+
+        modify(_.defineType(name, `type`)).as(`type`)
+      ).value
+    )
+
   override def defineStructType(
     name: NamedTypeToken[S],
     fields: Map[String, (Name[S], Type)]
   ): State[X, Option[StructType]] =
-    getState.map(_.definitions.get(name.value)).flatMap {
+    ensureNameNotDefined(name.value, name, ifDefined = none)(
-      case Some(_) => report(name, s"Data `${name.value}` was already defined").as(none)
+      fields.toList.traverse {
-      case None =>
+        case (field, (fieldName, t: DataType)) =>
-        fields.toList.traverse {
+          t match {
-          case (field, (fieldName, t: DataType)) =>
+            case _: StreamType => report(fieldName, s"Field '$field' has stream type").as(none)
-            t match {
+            case _ => (field -> t).some.pure[ST]
-              case _: StreamType => report(fieldName, s"Field '$field' has stream type").as(none)
+          }
-              case _ => (field -> t).some.pure[ST]
+        case (field, (fieldName, t)) =>
-            }
+          report(
-          case (field, (fieldName, t)) =>
+            fieldName,
-            report(
+            s"Field '$field' has unacceptable for struct field type '$t'"
-              fieldName,
+          ).as(none)
-              s"Field '$field' has unacceptable for struct field type '$t'"
+      }.map(_.sequence.map(_.toMap))
-            ).as(none)
+        .flatMap(
-        }.map(_.sequence.map(_.toMap))
+          _.map(SortedMap.from)
-          .flatMap(
+            .flatMap(NonEmptyMap.fromMap)
-            _.map(SortedMap.from)
+            .fold(
-              .flatMap(NonEmptyMap.fromMap)
+              report(name, s"Struct `${name.value}` has no fields").as(none)
-              .fold(
+            )(nonEmptyFields =>
-                report(name, s"Struct `${name.value}` has no fields").as(none)
+              val `type` = StructType(name.value, nonEmptyFields)
-              )(nonEmptyFields =>
+
-                val `type` = StructType(name.value, nonEmptyFields)
+              modify(_.defineType(name, `type`)).as(`type`.some)
-                modify { st =>
+            )
-                  st.copy(
+        )
-                    strict = st.strict.updated(name.value, `type`),
+    )
-                    definitions = st.definitions.updated(name.value, name)
-                  )
-                }.as(`type`.some)
-              )
-          )
-    }
 
   override def defineAlias(name: NamedTypeToken[S], target: Type): State[X, Boolean] =
     getState.map(_.definitions.get(name.value)).flatMap {
       case Some(n) if n == name => State.pure(false)
       case Some(_) => report(name, s"Type `${name.value}` was already defined").as(false)
       case None =>
-        modify(st =>
+        modify(_.defineType(name, target))
-          st.copy(
+          .productL(locations.addToken(name.value, name))
-            strict = st.strict.updated(name.value, target),
+          .as(true)
-            definitions = st.definitions.updated(name.value, name)
-          )
-        ).flatMap(_ => locations.addToken(name.value, name)).as(true)
     }
 
   override def resolveField(rootT: Type, op: IntoField[S]): State[X, Option[PropertyRaw]] = {
@@ -465,4 +483,22 @@ class TypesInterpreter[S[_], X](implicit
         ).as(frame -> Nil)
       else (frame -> frame.retVals.getOrElse(Nil)).pure
     ) <* stack.endScope
+
+  private def ensureNameNotDefined[A](
+    name: String,
+    token: Token[S],
+    ifDefined: => A
+  )(
+    ifNotDefined: => State[X, A]
+  ): State[X, A] = getState
+    .map(_.definitions.get(name))
+    .flatMap {
+      case Some(_) =>
+        // TODO: Point to both locations here
+        report(
+          token,
+          s"Name `${name}` was already defined here"
+        ).as(ifDefined)
+      case None => ifNotDefined
+    }
 }

semantics/src/main/scala/aqua/semantics/rules/types/TypesState.scala

@@ -9,129 +9,139 @@ import cats.data.Validated.{Invalid, Valid}
 import cats.data.{Chain, NonEmptyChain, ValidatedNec}
 import cats.kernel.Monoid
 import cats.syntax.option.*
+import cats.syntax.traverse.*
+import cats.syntax.validated.*
+import cats.syntax.apply.*
+import cats.syntax.bifunctor.*
+import cats.syntax.functor.*
+import cats.syntax.apply.*
 
 case class TypesState[S[_]](
-  fields: Map[String, (Name[S], Type)] = Map.empty[String, (Name[S], Type)],
+  fields: Map[String, (Name[S], Type)] = Map(),
-  strict: Map[String, Type] = Map.empty[String, Type],
+  strict: Map[String, Type] = Map.empty,
-  definitions: Map[String, NamedTypeToken[S]] = Map.empty[String, NamedTypeToken[S]],
+  definitions: Map[String, NamedTypeToken[S]] = Map(),
   stack: List[TypesState.Frame[S]] = Nil
 ) {
   def isDefined(t: String): Boolean = strict.contains(t)
+
+  def defineType(name: NamedTypeToken[S], `type`: Type): TypesState[S] =
+    copy(
+      strict = strict.updated(name.value, `type`),
+      definitions = definitions.updated(name.value, name)
+    )
+
+  def getType(name: String): Option[Type] =
+    strict.get(name)
+
+  def getTypeDefinition(name: String): Option[NamedTypeToken[S]] =
+    definitions.get(name)
 }
 
 object TypesStateHelper {
 
-  // TODO: an ugly return type, refactoring
+  final case class TypeResolution[S[_], +T](
-  // Returns type and a token with its definition
+    `type`: T,
-  def resolveTypeToken[S[_]](
+    definitions: List[(Token[S], NamedTypeToken[S])]
-    tt: TypeToken[S],
+  )
-    state: TypesState[S],
+
-    resolver: (
+  final case class TypeResolutionError[S[_]](
-      TypesState[S],
+    token: Token[S],
-      NamedTypeToken[S]
+    hint: String
-    ) => Option[(Type, List[(Token[S], NamedTypeToken[S])])]
+  )
-  ): Option[(Type, List[(Token[S], NamedTypeToken[S])])] =
+
+  def resolveTypeToken[S[_]](tt: TypeToken[S])(
+    state: TypesState[S]
+  ): Option[TypeResolution[S, Type]] =
     tt match {
       case TopBottomToken(_, isTop) =>
-        (if (isTop) TopType else BottomType, Nil).some
+        val `type` = if (isTop) TopType else BottomType
+
+        TypeResolution(`type`, Nil).some
       case ArrayTypeToken(_, dtt) =>
-        resolveTypeToken(dtt, state, resolver).collect { case (it: DataType, t) =>
+        resolveTypeToken(dtt)(state).collect { case TypeResolution(it: DataType, t) =>
-          (ArrayType(it), t)
+          TypeResolution(ArrayType(it), t)
         }
       case StreamTypeToken(_, dtt) =>
-        resolveTypeToken(dtt, state, resolver).collect { case (it: DataType, t) =>
+        resolveTypeToken(dtt)(state).collect { case TypeResolution(it: DataType, t) =>
-          (StreamType(it), t)
+          TypeResolution(StreamType(it), t)
         }
       case OptionTypeToken(_, dtt) =>
-        resolveTypeToken(dtt, state, resolver).collect { case (it: DataType, t) =>
+        resolveTypeToken(dtt)(state).collect { case TypeResolution(it: DataType, t) =>
-          (OptionType(it), t)
+          TypeResolution(OptionType(it), t)
-        }
-      case ctt: NamedTypeToken[S] =>
-        resolver(state, ctt)
-      case btt: BasicTypeToken[S] => (btt.value, Nil).some
-      case ArrowTypeToken(_, args, res) =>
-        val strictArgs =
-          args.map(_._2).map(resolveTypeToken(_, state, resolver)).collect {
-            case Some((dt: DataType, t)) =>
-              (dt, t)
-          }
-        val strictRes =
-          res.map(resolveTypeToken(_, state, resolver)).collect { case Some((dt: DataType, t)) =>
-            (dt, t)
-          }
-        Option.when(strictRes.length == res.length && strictArgs.length == args.length) {
-          val (sArgs, argTokens) = strictArgs.unzip
-          val (sRes, resTokens) = strictRes.unzip
-          (ArrowType(ProductType(sArgs), ProductType(sRes)), argTokens.flatten ++ resTokens.flatten)
         }
+      case ntt: NamedTypeToken[S] =>
+        val defs = state
+          .getTypeDefinition(ntt.value)
+          .toList
+          .map(ntt -> _)
+
+        state
+          .getType(ntt.value)
+          .map(typ => TypeResolution(typ, defs))
+      case btt: BasicTypeToken[S] =>
+        TypeResolution(btt.value, Nil).some
+      case att: ArrowTypeToken[S] =>
+        resolveArrowDef(att)(state).toOption
     }
 
-  def resolveArrowDef[S[_]](
+  def resolveArrowDef[S[_]](arrowTypeToken: ArrowTypeToken[S])(
-    arrowTypeToken: ArrowTypeToken[S],
+    state: TypesState[S]
-    state: TypesState[S],
+  ): ValidatedNec[TypeResolutionError[S], TypeResolution[S, ArrowType]] = {
-    resolver: (
+    val res = arrowTypeToken.res.traverse(typeToken =>
-      TypesState[S],
+      resolveTypeToken(typeToken)(state)
-      NamedTypeToken[S]
+        .toValidNec(
-    ) => Option[(Type, List[(Token[S], NamedTypeToken[S])])]
+          TypeResolutionError(
-  ): ValidatedNec[(Token[S], String), (ArrowType, List[(Token[S], NamedTypeToken[S])])] = {
+            typeToken,
-    val resType = arrowTypeToken.res.map(resolveTypeToken(_, state, resolver))
+            "Can not resolve the result type"
+          )
+        )
+    )
+    val args = arrowTypeToken.args.traverse { case (argName, typeToken) =>
+      resolveTypeToken(typeToken)(state)
+        .toValidNec(
+          TypeResolutionError(
+            typeToken,
+            "Can not resolve the argument type"
+          )
+        )
+        .map(argName.map(_.value) -> _)
+    }
 
-    NonEmptyChain
+    (args, res).mapN { (args, res) =>
-      .fromChain(Chain.fromSeq(arrowTypeToken.res.zip(resType).collect { case (dt, None) =>
+      val (argsLabeledTypes, argsTokens) =
-        dt -> "Cannot resolve the result type"
+        args.map { case lbl -> TypeResolution(typ, tkn) =>
-      }))
+          (lbl, typ) -> tkn
-      .fold[ValidatedNec[(Token[S], String), (ArrowType, List[(Token[S], NamedTypeToken[S])])]] {
+        }.unzip.map(_.flatten)
-        val (errs, argTypes) = arrowTypeToken.args.map { (argName, tt) =>
+      val (resTypes, resTokens) =
-          resolveTypeToken(tt, state, resolver)
+        res.map { case TypeResolution(typ, tkn) =>
-            .toRight(tt -> s"Type unresolved")
+          typ -> tkn
-            .map(argName.map(_.value) -> _)
+        }.unzip.map(_.flatten)
-        }
-          .foldLeft[
-            (
-              Chain[(Token[S], String)],
-              Chain[(Option[String], (Type, List[(Token[S], NamedTypeToken[S])]))]
-            )
-          ](
-            (
-              Chain.empty,
-              Chain.empty[(Option[String], (Type, List[(Token[S], NamedTypeToken[S])]))]
-            )
-          ) {
-            case ((errs, argTypes), Right(at)) => (errs, argTypes.append(at))
-            case ((errs, argTypes), Left(e)) => (errs.append(e), argTypes)
-          }
 
-        NonEmptyChain
+      val typ = ArrowType(
-          .fromChain(errs)
+        ProductType.maybeLabelled(argsLabeledTypes),
-          .fold[ValidatedNec[
+        ProductType(resTypes)
-            (Token[S], String),
+      )
-            (ArrowType, List[(Token[S], NamedTypeToken[S])])
+      val defs = (argsTokens ++ resTokens)
-          ]](
+
-            Valid {
+      TypeResolution(typ, defs)
-              val (labels, types) = argTypes.toList.unzip
+    }
-              val (resTypes, resTokens) = resType.flatten.unzip
-              (
-                ArrowType(
-                  ProductType.maybeLabelled(labels.zip(types.map(_._1))),
-                  ProductType(resTypes)
-                ),
-                types.flatMap(_._2) ++ resTokens.flatten
-              )
-            }
-          )(Invalid(_))
-      }(Invalid(_))
   }
 }
 
 object TypesState {
 
+  final case class TypeDefinition[S[_]](
+    token: NamedTypeToken[S],
+    `type`: Type
+  )
+
   case class Frame[S[_]](
     token: ArrowTypeToken[S],
     arrowType: ArrowType,
     retVals: Option[List[ValueRaw]]
   )
 
-  implicit def typesStateMonoid[S[_]]: Monoid[TypesState[S]] = new Monoid[TypesState[S]] {
+  given [S[_]]: Monoid[TypesState[S]] with {
     override def empty: TypesState[S] = TypesState()
 
     override def combine(x: TypesState[S], y: TypesState[S]): TypesState[S] =

semantics/src/test/scala/aqua/semantics/ArrowSemSpec.scala

@@ -15,7 +15,8 @@ import org.scalatest.flatspec.AnyFlatSpec
 import org.scalatest.matchers.should.Matchers
 
 class ArrowSemSpec extends AnyFlatSpec with Matchers with EitherValues {
-  import Utils.*
+
+  import Utils.{given, *}
 
   def program(arrowStr: String): Prog[State[CompilerState[cats.Id], *], Raw] = {
     import CompilerState.*

semantics/src/test/scala/aqua/semantics/ClosureSemSpec.scala

@@ -29,7 +29,7 @@ import org.scalatest.matchers.should.Matchers
 
 class ClosureSemSpec extends AnyFlatSpec with Matchers {
 
-  import Utils.*
+  import Utils.{given, *}
 
   val program: Prog[State[CompilerState[cats.Id], *], Raw] = {
     import CompilerState.*

semantics/src/test/scala/aqua/semantics/SemanticsSpec.scala

@@ -87,11 +87,10 @@ class SemanticsSpec extends AnyFlatSpec with Matchers with Inside {
 
   def testServiceCallStr(str: String) =
     CallArrowRawTag
-      .service(
+      .ability(
-        serviceId = LiteralRaw.quote("test"),
+        abilityName = "Test",
-        fnName = "testCallStr",
+        funcName = "testCallStr",
         call = Call(LiteralRaw.quote(str) :: Nil, Nil),
-        name = "Test",
         arrowType = ArrowType(
           ProductType.labelled(("s" -> ScalarType.string) :: Nil),
           ProductType(ScalarType.string :: Nil)
@@ -137,11 +136,10 @@ class SemanticsSpec extends AnyFlatSpec with Matchers with Inside {
     insideBody(script) { body =>
       val arrowType = ArrowType(NilType, ConsType.cons(ScalarType.string, NilType))
       val serviceCall = CallArrowRawTag
-        .service(
+        .ability(
-          serviceId = LiteralRaw.quote("srv1"),
+          abilityName = "A",
-          fnName = "fn1",
+          funcName = "fn1",
           call = emptyCall,
-          name = "A",
           arrowType = arrowType
         )
         .leaf

semantics/src/test/scala/aqua/semantics/Utils.scala

@@ -6,45 +6,35 @@ import aqua.parser.lift.Span
 import aqua.raw.{Raw, RawContext}
 import aqua.semantics.expr.func.ClosureSem
 import aqua.semantics.rules.errors.ReportErrors
-import aqua.semantics.rules.abilities.{AbilitiesInterpreter, AbilitiesState}
+import aqua.semantics.rules.abilities.{AbilitiesAlgebra, AbilitiesInterpreter, AbilitiesState}
-import aqua.semantics.rules.locations.DummyLocationsInterpreter
+import aqua.semantics.rules.locations.{DummyLocationsInterpreter, LocationsAlgebra}
-import aqua.semantics.rules.names.{NamesInterpreter, NamesState}
+import aqua.semantics.rules.names.{NamesAlgebra, NamesInterpreter, NamesState}
-import aqua.semantics.rules.types.{TypesInterpreter, TypesState}
+import aqua.semantics.rules.types.{TypesAlgebra, TypesInterpreter, TypesState}
 import aqua.types.*
+
 import cats.data.State
 import cats.{~>, Id}
 import monocle.Lens
 import monocle.macros.GenLens
 import monocle.syntax.all.*
+import aqua.semantics.rules.mangler.ManglerAlgebra
+import aqua.semantics.rules.mangler.ManglerInterpreter
 
 object Utils {
 
-  implicit val re: ReportErrors[Id, CompilerState[Id]] = new ReportErrors[Id, CompilerState[Id]] {
+  given ManglerAlgebra[State[CompilerState[Id], *]] =
+    new ManglerInterpreter[CompilerState[Id]]
 
-    override def apply(
+  given LocationsAlgebra[Id, State[CompilerState[Id], *]] =
-      st: CompilerState[Id],
-      token: Token[Id],
-      hints: List[String]
-    ): CompilerState[Id] =
-      st.focus(_.errors).modify(_.append(RulesViolated(token, hints)))
-  }
-
-  implicit val locationsInterpreter: DummyLocationsInterpreter[Id, CompilerState[Id]] =
     new DummyLocationsInterpreter[Id, CompilerState[Id]]()
 
-  implicit val ns: Lens[CompilerState[Id], NamesState[Id]] = GenLens[CompilerState[Id]](_.names)
+  given NamesAlgebra[Id, State[CompilerState[Id], *]] =
-
-  implicit val as: Lens[CompilerState[Id], AbilitiesState[Id]] =
-    GenLens[CompilerState[Id]](_.abilities)
-  implicit val ts: Lens[CompilerState[Id], TypesState[Id]] = GenLens[CompilerState[Id]](_.types)
-
-  implicit val alg: NamesInterpreter[Id, CompilerState[Id]] =
     new NamesInterpreter[Id, CompilerState[Id]]
 
-  implicit val typesInterpreter: TypesInterpreter[Id, CompilerState[Id]] =
+  given TypesAlgebra[Id, State[CompilerState[Id], *]] =
     new TypesInterpreter[Id, CompilerState[Id]]
 
-  implicit val abilitiesInterpreter: AbilitiesInterpreter[Id, CompilerState[Id]] =
+  given AbilitiesAlgebra[Id, State[CompilerState[Id], *]] =
     new AbilitiesInterpreter[Id, CompilerState[Id]]
 
   def spanToId: Span.S ~> Id = new (Span.S ~> Id) {

semantics/src/test/scala/aqua/semantics/ValuesAlgebraSpec.scala

@@ -1,32 +1,17 @@
 package aqua.semantics
 
 import aqua.semantics.rules.ValuesAlgebra
-import aqua.semantics.rules.names.NamesState
+import aqua.semantics.rules.abilities.{AbilitiesAlgebra, AbilitiesInterpreter, AbilitiesState}
-import aqua.semantics.rules.abilities.AbilitiesState
+import aqua.semantics.rules.names.{NamesAlgebra, NamesInterpreter, NamesState}
-import aqua.semantics.rules.types.TypesState
+import aqua.semantics.rules.definitions.{DefinitionsAlgebra, DefinitionsInterpreter}
-import aqua.semantics.rules.types.TypesAlgebra
+import aqua.semantics.rules.types.{TypesAlgebra, TypesInterpreter, TypesState}
-import aqua.semantics.rules.abilities.AbilitiesInterpreter
+import aqua.semantics.rules.locations.{DummyLocationsInterpreter, LocationsAlgebra}
-import aqua.semantics.rules.names.NamesAlgebra
+import aqua.semantics.rules.mangler.{ManglerAlgebra, ManglerInterpreter}
-import aqua.semantics.rules.definitions.DefinitionsAlgebra
-import aqua.semantics.rules.abilities.AbilitiesAlgebra
-import aqua.semantics.rules.names.NamesInterpreter
-import aqua.semantics.rules.definitions.DefinitionsInterpreter
-import aqua.semantics.rules.types.TypesInterpreter
-import aqua.semantics.rules.locations.LocationsAlgebra
-import aqua.semantics.rules.locations.DummyLocationsInterpreter
 import aqua.raw.value.{ApplyBinaryOpRaw, LiteralRaw}
 import aqua.raw.RawContext
 import aqua.types.*
-import aqua.parser.lexer.{
+import aqua.parser.lexer.*
-  CollectionToken,
+import aqua.raw.value.*
-  InfixToken,
-  LiteralToken,
-  Name,
-  PrefixToken,
-  ValueToken,
-  VarToken
-}
-import aqua.raw.value.ApplyUnaryOpRaw
 import aqua.parser.lexer.ValueToken.string
 
 import org.scalatest.flatspec.AnyFlatSpec
@@ -50,6 +35,8 @@ class ValuesAlgebraSpec extends AnyFlatSpec with Matchers with Inside {
     given LocationsAlgebra[Id, Interpreter] =
       new DummyLocationsInterpreter[Id, CompilerState[Id]]
 
+    given ManglerAlgebra[Interpreter] =
+      new ManglerInterpreter[CompilerState[Id]]
     given TypesAlgebra[Id, Interpreter] =
       new TypesInterpreter[Id, CompilerState[Id]]
     given AbilitiesAlgebra[Id, Interpreter] =

types/src/main/scala/aqua/types/Type.scala

@@ -243,31 +243,19 @@ case class OptionType(element: Type) extends BoxType {
 sealed trait NamedType extends Type {
   def name: String
   def fields: NonEmptyMap[String, Type]
-}
-
-// Struct is an unordered collection of labelled types
-// TODO: Make fields type `DataType`
-case class StructType(name: String, fields: NonEmptyMap[String, Type])
-    extends DataType with NamedType {
-
-  override def toString: String =
-    s"$name{${fields.map(_.toString).toNel.toList.map(kv => kv._1 + ": " + kv._2).mkString(", ")}}"
-}
-
-// Ability is an unordered collection of labelled types and arrows
-case class AbilityType(name: String, fields: NonEmptyMap[String, Type]) extends NamedType {
 
   /**
-   * Get all arrows defined in this ability and its sub-abilities.
+   * Get all arrows defined in this type and its sub-abilities.
-   * Paths to arrows are returned **without** ability name
+   * Paths to arrows are returned **without** type name
    * to allow renaming on call site.
    */
   lazy val arrows: Map[String, ArrowType] = {
-    def getArrowsEval(path: Option[String], ability: AbilityType): Eval[List[(String, ArrowType)]] =
+    def getArrowsEval(path: Option[String], nt: NamedType): Eval[List[(String, ArrowType)]] =
-      ability.fields.toNel.toList.flatTraverse {
+      nt.fields.toNel.toList.flatTraverse {
-        case (abName, abType: AbilityType) =>
+        // sub-arrows could be in abilities or services
-          val newPath = path.fold(abName)(AbilityType.fullName(_, abName))
+        case (innerName, innerType: (ServiceType | AbilityType)) =>
-          getArrowsEval(newPath.some, abType)
+          val newPath = path.fold(innerName)(AbilityType.fullName(_, innerName))
+          getArrowsEval(newPath.some, innerType)
         case (aName, aType: ArrowType) =>
           val newPath = path.fold(aName)(AbilityType.fullName(_, aName))
           List(newPath -> aType).pure
@@ -278,16 +266,17 @@ case class AbilityType(name: String, fields: NonEmptyMap[String, Type]) extends
   }
 
   /**
-   * Get all abilities defined in this ability and its sub-abilities.
+   * Get all abilities defined in this type and its sub-abilities.
-   * Paths to abilities are returned **without** ability name
+   * Paths to abilities are returned **without** type name
    * to allow renaming on call site.
    */
   lazy val abilities: Map[String, AbilityType] = {
     def getAbilitiesEval(
       path: Option[String],
-      ability: AbilityType
+      nt: NamedType
     ): Eval[List[(String, AbilityType)]] =
-      ability.fields.toNel.toList.flatTraverse {
+      nt.fields.toNel.toList.flatTraverse {
+        // sub-abilities could be only in abilities
         case (abName, abType: AbilityType) =>
           val fullName = path.fold(abName)(AbilityType.fullName(_, abName))
           getAbilitiesEval(fullName.some, abType).map(
@@ -300,16 +289,17 @@ case class AbilityType(name: String, fields: NonEmptyMap[String, Type]) extends
   }
 
   /**
-   * Get all variables defined in this ability and its sub-abilities.
+   * Get all variables defined in this type and its sub-abilities.
-   * Paths to variables are returned **without** ability name
+   * Paths to variables are returned **without** type name
    * to allow renaming on call site.
    */
   lazy val variables: Map[String, DataType] = {
     def getVariablesEval(
       path: Option[String],
-      ability: AbilityType
+      nt: NamedType
     ): Eval[List[(String, DataType)]] =
-      ability.fields.toNel.toList.flatTraverse {
+      nt.fields.toNel.toList.flatTraverse {
+        // sub-variables could be only in abilities
         case (abName, abType: AbilityType) =>
           val newPath = path.fold(abName)(AbilityType.fullName(_, abName))
           getVariablesEval(newPath.some, abType)
@@ -321,6 +311,25 @@ case class AbilityType(name: String, fields: NonEmptyMap[String, Type]) extends
 
     getVariablesEval(None, this).value.toMap
   }
+}
+
+// Struct is an unordered collection of labelled types
+// TODO: Make fields type `DataType`
+case class StructType(name: String, fields: NonEmptyMap[String, Type])
+    extends DataType with NamedType {
+
+  override def toString: String =
+    s"$name{${fields.map(_.toString).toNel.toList.map(kv => kv._1 + ": " + kv._2).mkString(", ")}}"
+}
+
+case class ServiceType(name: String, fields: NonEmptyMap[String, ArrowType]) extends NamedType {
+
+  override def toString: String =
+    s"service $name{${fields.map(_.toString).toNel.toList.map(kv => kv._1 + ": " + kv._2).mkString(", ")}}"
+}
+
+// Ability is an unordered collection of labelled types and arrows
+case class AbilityType(name: String, fields: NonEmptyMap[String, Type]) extends NamedType {
 
   override def toString: String =
     s"ability $name{${fields.map(_.toString).toNel.toList.map(kv => kv._1 + ": " + kv._2).mkString(", ")}}"

types/src/test/scala/aqua/types/TypeSpec.scala

@@ -170,7 +170,7 @@ class TypeSpec extends AnyFlatSpec with Matchers {
     accepts(four, one) should be(false)
   }
 
-  "labeled types" should "create correc labels" in {
+  "labeled types" should "create correct labels" in {
     val cons = LabeledConsType(
       "arg1",
       ArrowType(