feat(compiler): Allow redeclaring functions [LNG-357] (#1127)

* Allow dots in use ... as

* Add tests

* Refactor implicits

* Use QName in module name

* Fix test

* Refactor declares

* Add PName

* Propagate nested abilities

* Fix compilation

* Do not propagate context

* Use alignCombine

* Add test

* Add more tests

* Refactor test

* Remove unused function

* Refactor test

* Refactor, add comments

* Checkout aqua-src

build.sbt

@@ -26,6 +26,8 @@ val commons = Seq(
   scalaVersion := scalaV,
   libraryDependencies ++= Seq(
     "com.outr"          %%% "scribe"          % scribeV,
+    "dev.optics"        %%% "monocle-core"    % monocleV,
+    "dev.optics"        %%% "monocle-macro"   % monocleV,
     "org.scalatest"     %%% "scalatest"       % scalaTestV           % Test,
     "org.scalatestplus" %%% "scalacheck-1-17" % scalaTestScalaCheckV % Test
   ),
@@ -201,12 +203,6 @@ lazy val semantics = crossProject(JVMPlatform, JSPlatform)
   .withoutSuffixFor(JVMPlatform)
   .crossType(CrossType.Pure)
   .settings(commons)
-  .settings(
-    libraryDependencies ++= Seq(
-      "dev.optics" %%% "monocle-core"  % monocleV,
-      "dev.optics" %%% "monocle-macro" % monocleV
-    )
-  )
   .dependsOn(raw, parser, errors, mangler)
 
 lazy val compiler = crossProject(JVMPlatform, JSPlatform)
@@ -287,6 +283,7 @@ lazy val helpers = crossProject(JVMPlatform, JSPlatform)
       "org.typelevel" %%% "cats-free" % catsV
     )
   )
+  .dependsOn(errors)
 
 lazy val errors = crossProject(JVMPlatform, JSPlatform)
   .withoutSuffixFor(JVMPlatform)

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

@@ -29,6 +29,7 @@ import cats.syntax.show.*
 import org.scalatest.Inside
 import org.scalatest.flatspec.AnyFlatSpec
 import org.scalatest.matchers.should.Matchers
+import scala.annotation.tailrec
 
 class AquaCompilerSpec extends AnyFlatSpec with Matchers with Inside {
   import ModelBuilder.*
@@ -497,10 +498,14 @@ class AquaCompilerSpec extends AnyFlatSpec with Matchers with Inside {
     }
   }
 
-  val moduleNames = List("Test", "Imp", "Sub", "Path").inits
-    .takeWhile(_.nonEmpty)
-    .map(_.mkString("."))
-    .toList
+  def paths(parts: List[String]): List[String] =
+    parts.inits
+      .takeWhile(_.nonEmpty)
+      .map(_.mkString("."))
+      .toList
+
+  val moduleNames = paths(List("Test", "Imp", "Sub", "Path"))
+  val renames = paths(List("Renamed", "With", "New", "Name"))
 
   it should "import function with `use`" in {
     def test(name: String, rename: Option[String]) = {
@@ -536,13 +541,15 @@ class AquaCompilerSpec extends AnyFlatSpec with Matchers with Inside {
     }
 
     moduleNames.foreach { name =>
-      val rename = "Imported"
 
       withClue(s"Testing $name") {
         test(name, None)
       }
-      withClue(s"Testing $name as $rename") {
-        test(name, rename.some)
+
+      renames.foreach { rename =>
+        withClue(s"Testing $name as $rename") {
+          test(name, rename.some)
+        }
       }
     }
   }
@@ -664,13 +671,15 @@ class AquaCompilerSpec extends AnyFlatSpec with Matchers with Inside {
     }
 
     moduleNames.foreach { name =>
-      val rename = "Imported"
 
       withClue(s"Testing $name") {
         test(name, None)
       }
-      withClue(s"Testing $name as $rename") {
-        test(name, rename.some)
+
+      renames.foreach { rename =>
+        withClue(s"Testing $name as $rename") {
+          test(name, rename.some)
+        }
       }
     }
   }
@@ -733,13 +742,15 @@ class AquaCompilerSpec extends AnyFlatSpec with Matchers with Inside {
     }
 
     moduleNames.foreach { name =>
-      val rename = "Imported"
 
       withClue(s"Testing $name") {
         test(name, None)
       }
-      withClue(s"Testing $name as $rename") {
-        test(name, rename.some)
+
+      renames.foreach { rename =>
+        withClue(s"Testing $name as $rename") {
+          test(name, rename.some)
+        }
       }
     }
   }
@@ -878,6 +889,161 @@ class AquaCompilerSpec extends AnyFlatSpec with Matchers with Inside {
       }
   }
 
+  it should "import redeclared functions" in {
+
+    final case class Imp(
+      idx: Int,
+      name: String,
+      rename: Option[String] = None,
+      use: Option[Imp] = None
+    ) {
+      def withUse(other: Imp): Imp = copy(use = Some(other))
+
+      lazy val path: String = s"import$idx.aqua"
+
+      lazy val declares: List[String] = use
+        .map(u => u.declares.map(n => s"${u.access}.$n"))
+        .getOrElse(Nil)
+        .prepended("foo")
+
+      lazy val code: String =
+        s"""|aqua $name declares ${declares.mkString(", ")}
+            |
+            |${use.fold("")(_.usage)}
+            |
+            |func foo() -> i32:
+            |  <- $idx
+            |""".stripMargin
+
+      lazy val usage: String = s"use \"$path\"" + rename.fold("")(n => s" as $n")
+
+      lazy val access: String = rename.getOrElse(name)
+    }
+
+    type NameRename = (String, Option[String])
+
+    def test(imps: List[NameRename]) = {
+      (imps.length > 0) should be(true)
+
+      val top = imps.zipWithIndex.map { case ((name, rename), idx) =>
+        Imp(idx + 1, name, rename)
+      }.reduceRight { case (cur, prev) =>
+        cur.withUse(prev)
+      }
+
+      val (calls, vars) = top.declares.zipWithIndex.map { case (decl, idx) =>
+        val v = s"v$idx"
+        val call = s"$v <- ${top.access}.$decl()"
+        call -> v
+      }.unzip
+
+      val main =
+        s"""|aqua Main
+            |
+            |export main
+            |
+            |${top.usage}
+            |
+            |func main() -> i32:
+            |  ${calls.mkString("\n  ")}
+            |  <- ${vars.mkString(" + ")}
+            |""".stripMargin
+
+      val imports = List
+        .unfold(top.some)(
+          _.map(i => i -> i.use)
+        )
+        .map(i => i.path -> i.code)
+        .toMap
+
+      val src = Map(
+        "main.aqua" -> main
+      )
+
+      val transformCfg = TransformConfig(relayVarName = None)
+
+      insideRes(src, imports, transformCfg)(
+        "main"
+      ) { case main :: _ =>
+        val l = imps.length
+        val res = LiteralModel.number(l * (l + 1) / 2)
+        val expected = XorRes.wrap(
+          respCall(transformCfg, res, initPeer),
+          errorCall(transformCfg, 0, initPeer)
+        )
+
+        main.body.equalsOrShowDiff(expected) should be(true)
+      }
+    }
+
+    // Simple
+    (1 to 10).foreach { i =>
+      val names = (1 to i).map(n => s"Imp$n").toList
+      withClue(s"Testing ${names.mkString(" -> ")}") {
+        test(names.map(_ -> none))
+      }
+    }
+
+    extension [A](l: List[List[A]]) {
+      def rotate: List[List[A]] =
+        l.foldLeft(List.empty[List[A]]) { case (acc, next) =>
+          if (acc.isEmpty) next.map(List(_))
+          else
+            for {
+              elem <- next
+              prev <- acc
+            } yield elem +: prev
+        }
+    }
+
+    // With subpaths
+    (1 to 4).foreach { i =>
+      (1 to i)
+        .map(idx =>
+          paths(
+            List("Imp", "Sub", "Path")
+              .map(p => s"$p$idx")
+          )
+        )
+        .toList
+        .rotate
+        .foreach(names =>
+          withClue(s"Testing ${names.mkString(" -> ")}") {
+            test(names.map(_ -> none))
+          }
+        )
+    }
+
+    // With renames
+    (1 to 3).foreach { i =>
+      (1 to i)
+        .map(idx =>
+          for {
+            name <- paths(
+              List("Imp", "Sub", "Path")
+                .map(p => s"$p$idx")
+            )
+            rename <- None :: paths(
+              List("Rename", "To", "Other")
+                .map(p => s"$p$idx")
+            ).map(_.some)
+          } yield name -> rename
+        )
+        .toList
+        .rotate
+        .foreach(names =>
+          val message = names.map { case (n, r) =>
+            s"$n${r.fold("")(n => s" as $n")}"
+          }.mkString(" -> ")
+
+          withClue(s"Testing $message") {
+            test(names)
+          }
+        )
+    }
+
+  }
+
   it should "not generate error propagation in `if` with `noXor = true`" in {
     val src = Map(
       "index.aqua" ->

language-server/language-server-api/src/main/scala/aqua/lsp/LspContext.scala

@@ -1,5 +1,6 @@
 package aqua.lsp
 
+import aqua.helpers.data.PName
 import aqua.parser.lexer.{LiteralToken, NamedTypeToken, Token}
 import aqua.raw.{RawContext, RawPart}
 import aqua.semantics.header.Picker
@@ -94,15 +95,12 @@ object LspContext {
     ): LspContext[S] =
       ctx.copy(importPaths = importPaths)
 
-    override def setModule(
-      ctx: LspContext[S],
-      name: String
-    ): LspContext[S] =
+    override def setModule(ctx: LspContext[S], name: Option[String]): LspContext[S] =
       ctx.copy(raw = ctx.raw.setModule(name))
 
     override def setDeclares(
       ctx: LspContext[S],
-      declares: Set[String]
+      declares: Set[PName]
     ): LspContext[S] =
       ctx.copy(raw = ctx.raw.setDeclares(declares))
 
@@ -145,6 +143,9 @@ object LspContext {
           )
         )
 
+    override def pick(ctx: LspContext[S], name: PName, declared: Boolean): Option[LspContext[S]] =
+      ctx.raw.pick(name, declared).map(rc => ctx.copy(raw = rc))
+
     override def pickHeader(ctx: LspContext[S]): LspContext[S] = ctx.copy(raw = ctx.raw.pickHeader)
 
     override def pickDeclared(ctx: LspContext[S]): LspContext[S] =

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

@@ -1,5 +1,6 @@
 package aqua.raw
 
+import aqua.helpers.data.PName
 import aqua.raw.arrow.FuncRaw
 import aqua.raw.value.ValueRaw
 import aqua.types.{AbilityType, StructType, Type}
@@ -8,8 +9,11 @@ import cats.Monoid
 import cats.Semigroup
 import cats.data.Chain
 import cats.data.NonEmptyMap
+import cats.syntax.align.*
 import cats.syntax.monoid.*
 import cats.syntax.option.*
+import monocle.Lens
+import monocle.macros.GenLens
 import scala.collection.immutable.SortedMap
 
 /**
@@ -28,7 +32,7 @@ import scala.collection.immutable.SortedMap
  */
 case class RawContext(
   module: Option[String] = None,
-  declares: Set[String] = Set.empty,
+  declares: Set[PName] = Set.empty,
   exports: Map[String, Option[String]] = Map.empty,
   parts: Chain[(RawContext, RawPart)] = Chain.empty,
   abilities: Map[String, RawContext] = Map.empty
@@ -51,6 +55,9 @@ case class RawContext(
       }
       .map(prefixFirst(prefix, _))
 
+  lazy val allAbilities: Map[String, RawContext] =
+    all(_.abilities)
+
   lazy val services: Map[String, ServiceRaw] = collectPartsMap { case srv: ServiceRaw => srv }
 
   lazy val allServices: Map[String, ServiceRaw] =
@@ -87,10 +94,11 @@ case class RawContext(
     all(_.definedAbilities)
 
   lazy val allNames: Set[String] =
+    // TODO: How about names in abilities?
     parts.map { case (_, p) => p.name }.toList.toSet
 
   lazy val declaredNames: Set[String] =
-    allNames.intersect(declares)
+    declares.map(_.value).toSet
 
   override def toString: String =
     s"""|module: ${module.getOrElse("unnamed")}
@@ -105,6 +113,18 @@ case class RawContext(
 object RawContext {
   val blank: RawContext = RawContext()
 
+  val partsLens: Lens[RawContext, Chain[(RawContext, RawPart)]] =
+    GenLens[RawContext](_.parts)
+
+  val abilitiesLens: Lens[RawContext, Map[String, RawContext]] =
+    GenLens[RawContext](_.abilities)
+
+  def fromParts(parts: Chain[(RawContext, RawPart)]): RawContext =
+    partsLens.set(parts)(blank)
+
+  def fromAbilities(abilities: Map[String, RawContext]): RawContext =
+    abilitiesLens.set(abilities)(blank)
+
   given Monoid[RawContext] with {
 
     override def empty: RawContext = blank
@@ -115,7 +135,8 @@ object RawContext {
         x.declares ++ y.declares,
         x.exports ++ y.exports,
         x.parts ++ y.parts,
-        x.abilities ++ y.abilities
+        // This combines abilities (which are RawContexts too) recursively
+        x.abilities.alignCombine(y.abilities)
       )
   }
 }

parser/src/main/scala/aqua/parser/Expr.scala

@@ -3,21 +3,18 @@ package aqua.parser
 import aqua.parser.Ast.Tree
 import aqua.parser.lexer.Token
 import aqua.parser.lexer.Token.*
-import aqua.parser.expr.func.ReturnExpr
 import aqua.parser.lift.LiftParser.*
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 import aqua.parser.lift.{LiftParser, Span}
-import aqua.parser.Ast.Tree
-import aqua.parser.ListToTreeConverter
 
+import cats.Show
 import cats.data.Chain.:==
+import cats.data.Validated.{invalid, invalidNec, invalidNel, valid, validNec, validNel}
 import cats.data.{Chain, NonEmptyChain, Validated, ValidatedNec}
 import cats.free.Cofree
-import cats.Show
-import cats.data.Validated.{invalid, invalidNec, invalidNel, valid, validNec, validNel}
 import cats.parse.{Parser as P, Parser0 as P0}
 import cats.syntax.comonad.*
-import cats.{~>, Comonad, Eval}
+import cats.{Comonad, Eval, ~>}
 import scribe.Logging
 
 abstract class Expr[F[_]](val companion: Expr.Companion, val token: Token[F]) {

parser/src/main/scala/aqua/parser/Parser.scala

@@ -2,9 +2,10 @@ package aqua.parser
 
 import aqua.parser.expr.RootExpr
 import aqua.parser.head.Header
-import aqua.parser.lift.LiftParser.LiftErrorOps
-import aqua.parser.lift.Span.S
-import aqua.parser.lift.{LiftParser, Span}
+import aqua.parser.lift.LiftParser
+import aqua.parser.lift.LiftParser.*
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
 
 import cats.data.{Validated, ValidatedNec}
 import cats.free.Cofree

parser/src/main/scala/aqua/parser/expr/AliasExpr.scala

@@ -4,11 +4,12 @@ import aqua.parser.Expr
 import aqua.parser.lexer.Token._
 import aqua.parser.lexer.{NamedTypeToken, TypeToken}
 import aqua.parser.lift.LiftParser
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
+
 import cats.Comonad
 import cats.parse.Parser
 import cats.~>
-import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan}
 
 case class AliasExpr[F[_]](name: NamedTypeToken[F], target: TypeToken[F])
     extends Expr[F](AliasExpr, name) {

parser/src/main/scala/aqua/parser/expr/ArrowTypeExpr.scala

@@ -5,7 +5,7 @@ import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{ArrowTypeToken, BasicTypeToken, Name}
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 
 import cats.Comonad
 import cats.parse.Parser

parser/src/main/scala/aqua/parser/expr/ConstantExpr.scala

@@ -1,16 +1,17 @@
 package aqua.parser.expr
 
 import aqua.parser.Expr
-import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.*
+import aqua.parser.lexer.PrefixToken
+import aqua.parser.lexer.Token.*
+import aqua.parser.lexer.VarToken
 import aqua.parser.lift.LiftParser
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
+
 import cats.Comonad
 import cats.parse.Parser as P
 import cats.~>
-import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
-import aqua.parser.lexer.PrefixToken
-import aqua.parser.lexer.VarToken
 
 case class ConstantExpr[F[_]](
   name: Name[F],

parser/src/main/scala/aqua/parser/expr/DataStructExpr.scala

@@ -4,11 +4,12 @@ import aqua.parser.Expr
 import aqua.parser.lexer.NamedTypeToken
 import aqua.parser.lexer.Token.*
 import aqua.parser.lift.LiftParser
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
+
 import cats.Comonad
 import cats.parse.Parser
 import cats.~>
-import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
 
 case class DataStructExpr[F[_]](name: NamedTypeToken[F]) extends Expr[F](DataStructExpr, name) {
   override def mapK[K[_]: Comonad](fk: F ~> K): DataStructExpr[K] = copy(name.mapK(fk))

parser/src/main/scala/aqua/parser/expr/FieldTypeExpr.scala

@@ -5,7 +5,7 @@ import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{BasicTypeToken, Name, StreamTypeToken}
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 
 import cats.Comonad
 import cats.parse.Parser

parser/src/main/scala/aqua/parser/expr/FuncExpr.scala

@@ -1,17 +1,18 @@
 package aqua.parser.expr
 
 import aqua.parser.expr.func.ArrowExpr
-import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.Name
+import aqua.parser.lexer.Token.*
 import aqua.parser.lift.LiftParser
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
 import aqua.parser.{Ast, Expr}
+
 import cats.Comonad
 import cats.data.{Validated, ValidatedNec}
 import cats.free.Cofree
 import cats.parse.Parser
 import cats.~>
-import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
 
 case class FuncExpr[F[_]](
   name: Name[F]

parser/src/main/scala/aqua/parser/expr/RootExpr.scala

@@ -3,8 +3,10 @@ package aqua.parser.expr
 import aqua.parser.Ast.Tree
 import aqua.parser.lexer.Token
 import aqua.parser.lexer.Token.*
+import aqua.parser.lift.LiftParser
 import aqua.parser.lift.LiftParser.*
-import aqua.parser.lift.{LiftParser, Span}
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
 import aqua.parser.{Expr, ParserError}
 
 import cats.data.{Chain, NonEmptyChain, NonEmptyList, Validated, ValidatedNec}
@@ -21,7 +23,6 @@ case class RootExpr[F[_]](point: Token[F]) extends Expr[F](RootExpr, point) {
 }
 
 object RootExpr extends Expr.Companion {
-  import Span.*
 
   def validChildren: List[Expr.Lexem] =
     ServiceExpr :: AliasExpr :: DataStructExpr :: AbilityExpr :: ConstantExpr :: FuncExpr :: Nil

parser/src/main/scala/aqua/parser/expr/ServiceExpr.scala

@@ -4,11 +4,12 @@ import aqua.parser.Expr
 import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{NamedTypeToken, ValueToken}
 import aqua.parser.lift.LiftParser
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
+
 import cats.Comonad
 import cats.parse.Parser
 import cats.~>
-import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
 
 case class ServiceExpr[F[_]](name: NamedTypeToken[F], id: Option[ValueToken[F]])
     extends Expr[F](ServiceExpr, name) {

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

@@ -3,8 +3,9 @@ package aqua.parser.expr.func
 import aqua.parser.lexer.{ArrowTypeToken, BasicTypeToken, NamedTypeToken, TypeToken, ValueToken}
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 import aqua.parser.{ArrowReturnError, Ast, Expr, ParserError}
+
 import cats.Comonad
 import cats.parse.Parser
 import cats.~>

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

@@ -5,10 +5,11 @@ import aqua.parser.expr.func.AssignmentExpr
 import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{CollectionToken, Name, ValueToken}
 import aqua.parser.lift.LiftParser
-import cats.parse.Parser as P
-import cats.{~>, Comonad}
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
+
+import cats.parse.Parser as P
+import cats.{Comonad, ~>}
 
 case class AssignmentExpr[F[_]](
   variable: Name[F],

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

@@ -4,11 +4,12 @@ import aqua.parser.Expr
 import aqua.parser.expr.func.CallArrowExpr
 import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{CallArrowToken, Name, ValueToken, VarToken}
+import aqua.parser.lift.Span.{given, *}
 import aqua.parser.lift.{LiftParser, Span}
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+
 import cats.data.NonEmptyList
 import cats.parse.{Parser as P, Parser0 as P0}
-import cats.{~>, Comonad}
+import cats.{Comonad, ~>}
 
 case class CallArrowExpr[F[_]](
   variables: List[Name[F]],
@@ -27,7 +28,8 @@ case class CallArrowExpr[F[_]](
 object CallArrowExpr extends Expr.Leaf {
 
   override val p: P[CallArrowExpr[Span.S]] = {
-    val variables: P0[Option[NonEmptyList[Name[Span.S]]]] = (comma(Name.variable) <* ` <- `).backtrack.?
+    val variables: P0[Option[NonEmptyList[Name[Span.S]]]] =
+      (comma(Name.variable) <* ` <- `).backtrack.?
 
     // TODO:    Restrict to function call only
     //          or allow any expression?

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

@@ -5,10 +5,11 @@ import aqua.parser.expr.func.{CatchExpr, TryExpr}
 import aqua.parser.lexer.Name
 import aqua.parser.lexer.Token.*
 import aqua.parser.lift.LiftParser
-import cats.parse.Parser
-import cats.{~>, Comonad}
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
+
+import cats.parse.Parser
+import cats.{Comonad, ~>}
 
 case class CatchExpr[F[_]](name: Name[F]) extends Expr[F](CatchExpr, name) {
   def mapK[K[_]: Comonad](fk: F ~> K): CatchExpr[K] = copy(name.mapK(fk))

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

@@ -4,13 +4,15 @@ import aqua.parser.expr.func.ArrowExpr
 import aqua.parser.lexer.Name
 import aqua.parser.lexer.Token.*
 import aqua.parser.lift.LiftParser
+import aqua.parser.lift.LiftParser.*
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
 import aqua.parser.{Ast, Expr, ParserError}
+
 import cats.data.{Validated, ValidatedNec}
 import cats.free.Cofree
 import cats.parse.Parser
-import cats.{~>, Comonad}
-import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import cats.{Comonad, ~>}
 
 case class ClosureExpr[F[_]](
   name: Name[F],

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

@@ -6,10 +6,11 @@ import aqua.parser.lexer.Token
 import aqua.parser.lexer.Token.`co`
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.LiftParser.*
-import cats.parse.Parser
-import cats.{~>, Comonad}
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
+
+import cats.parse.Parser
+import cats.{Comonad, ~>}
 
 case class CoExpr[F[_]](point: Token[F]) extends Expr[F](CoExpr, point) {
   def mapK[K[_]: Comonad](fk: F ~> K): CoExpr[K] = copy(point.mapK(fk))

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

@@ -6,7 +6,7 @@ import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{BasicTypeToken, Name, Token, TypeToken}
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 
 import cats.parse.Parser as P
 import cats.{Comonad, ~>}

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

@@ -6,12 +6,13 @@ import aqua.parser.lexer.Token
 import aqua.parser.lexer.Token.*
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.LiftParser.*
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
+
 import cats.parse.Parser
-import cats.{~>, Comonad}
 import cats.syntax.comonad.*
 import cats.syntax.functor.*
-import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import cats.{Comonad, ~>}
 
 case class ElseOtherwiseExpr[F[_]](kind: ElseOtherwiseExpr.Kind, point: Token[F])
     extends Expr[F](ElseOtherwiseExpr, point) {

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

@@ -7,7 +7,7 @@ import aqua.parser.lexer.{Name, ValueToken}
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.LiftParser.*
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 
 import cats.parse.Parser as P
 import cats.syntax.comonad.*

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

@@ -5,11 +5,12 @@ import aqua.parser.expr.func.{ForExpr, IfExpr}
 import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{LiteralToken, ValueToken}
 import aqua.parser.lift.LiftParser
-import aqua.types.LiteralType
-import cats.parse.Parser as P
-import cats.{~>, Comonad}
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
+import aqua.types.LiteralType
+
+import cats.parse.Parser as P
+import cats.{Comonad, ~>}
 
 case class IfExpr[F[_]](value: ValueToken[F]) extends Expr[F](IfExpr, value) {
 

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

@@ -4,11 +4,12 @@ import aqua.parser.Expr
 import aqua.parser.expr.*
 import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{PropertyToken, ValueToken}
+import aqua.parser.lift.Span.{given, *}
 import aqua.parser.lift.{LiftParser, Span}
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
-import cats.parse.Parser
-import cats.{~>, Comonad}
+
 import cats.data.NonEmptyList
+import cats.parse.Parser
+import cats.{Comonad, ~>}
 
 case class JoinExpr[F[_]](values: NonEmptyList[ValueToken[F]])
     extends Expr[F](JoinExpr, values.head) {

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

@@ -5,10 +5,11 @@ import aqua.parser.expr.*
 import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.ValueToken
 import aqua.parser.lift.LiftParser
-import cats.parse.Parser as P
-import cats.{~>, Comonad}
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
+
+import cats.parse.Parser as P
+import cats.{Comonad, ~>}
 
 case class OnExpr[F[_]](peerId: ValueToken[F], via: List[ValueToken[F]])
     extends Expr[F](OnExpr, peerId) {

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

@@ -6,10 +6,11 @@ import aqua.parser.lexer.Token
 import aqua.parser.lexer.Token.*
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.LiftParser.*
-import cats.parse.Parser
-import cats.{~>, Comonad}
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
+
+import cats.parse.Parser
+import cats.{Comonad, ~>}
 
 case class ParExpr[F[_]](point: Token[F]) extends Expr[F](ParExpr, point) {
 

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

@@ -6,11 +6,12 @@ import aqua.parser.lexer.Token.{`parseq`, *}
 import aqua.parser.lexer.{Name, ValueToken}
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.LiftParser.*
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
+
 import cats.parse.Parser as P
 import cats.syntax.comonad.*
-import cats.{~>, Comonad}
-import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import cats.{Comonad, ~>}
 
 case class ParSeqExpr[F[_]](
   item: Name[F],

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

@@ -5,10 +5,11 @@ import aqua.parser.expr.func.PushToStreamExpr
 import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{Name, ValueToken}
 import aqua.parser.lift.LiftParser
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
+
 import cats.parse.Parser as P
 import cats.{Comonad, ~>}
-import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
 
 case class PushToStreamExpr[F[_]](
   stream: Name[F],

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

@@ -5,11 +5,12 @@ import aqua.parser.expr.func.ReturnExpr
 import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.ValueToken
 import aqua.parser.lift.LiftParser
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
+
 import cats.data.NonEmptyList
 import cats.parse.Parser
-import cats.{~>, Comonad}
-import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import cats.{Comonad, ~>}
 
 case class ReturnExpr[F[_]](values: NonEmptyList[ValueToken[F]])
     extends Expr[F](ReturnExpr, values.head) {

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

@@ -5,10 +5,11 @@ import aqua.parser.expr.func.ServiceIdExpr
 import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{NamedTypeToken, ValueToken}
 import aqua.parser.lift.LiftParser
-import cats.parse.Parser as P
-import cats.{~>, Comonad}
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
+
+import cats.parse.Parser as P
+import cats.{Comonad, ~>}
 
 case class ServiceIdExpr[F[_]](service: NamedTypeToken[F], id: ValueToken[F])
     extends Expr[F](ServiceIdExpr, service) {

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

@@ -4,11 +4,12 @@ import aqua.parser.Expr
 import aqua.parser.expr.func.{IfExpr, TryExpr}
 import aqua.parser.lexer.Token
 import aqua.parser.lexer.Token.*
-import aqua.parser.lift.{LiftParser, Span}
 import aqua.parser.lift.LiftParser.*
+import aqua.parser.lift.Span.{given, *}
+import aqua.parser.lift.{LiftParser, Span}
+
 import cats.parse.Parser as P
 import cats.{Comonad, ~>}
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
 
 case class TryExpr[F[_]](point: Token[F]) extends Expr[F](TryExpr, point) {
 

parser/src/main/scala/aqua/parser/head/ExportExpr.scala

@@ -4,7 +4,7 @@ import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{LiteralToken, Token, ValueToken}
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 
 import cats.Comonad
 import cats.data.NonEmptyList

parser/src/main/scala/aqua/parser/head/FromExpr.scala

@@ -1,16 +1,16 @@
 package aqua.parser.head
 
-import cats.Comonad
-import cats.data.NonEmptyList
-import cats.parse.Parser as P
-import cats.~>
-import cats.syntax.bifunctor.*
-
 import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{Ability, Name}
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
+
+import cats.Comonad
+import cats.data.NonEmptyList
+import cats.parse.Parser as P
+import cats.syntax.bifunctor.*
+import cats.~>
 
 trait FromExpr[F[_]] {
   def imports: NonEmptyList[FromExpr.NameOrAbAs[F]]

parser/src/main/scala/aqua/parser/head/Header.scala

@@ -6,7 +6,7 @@ import aqua.parser.lexer.Token.` \n+`
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.LiftParser.*
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 
 import cats.data.Chain
 import cats.free.Cofree

parser/src/main/scala/aqua/parser/head/HeaderExpr.scala

@@ -4,7 +4,7 @@ import aqua.parser.Ast
 import aqua.parser.lexer.Token
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 
 import cats.Show
 import cats.data.Chain

parser/src/main/scala/aqua/parser/head/ImportExpr.scala

@@ -4,7 +4,7 @@ import aqua.parser.lexer.Token._
 import aqua.parser.lexer.{LiteralToken, ValueToken}
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 
 import cats.Comonad
 import cats.parse.Parser

parser/src/main/scala/aqua/parser/head/ImportFromExpr.scala

@@ -4,7 +4,7 @@ import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{LiteralToken, ValueToken}
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 
 import cats.Comonad
 import cats.data.NonEmptyList

parser/src/main/scala/aqua/parser/head/ModuleExpr.scala

@@ -1,14 +1,16 @@
 package aqua.parser.head
 
+import aqua.parser.lexer.QName
 import aqua.parser.lexer.Token
 import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{Ability, LiteralToken, Name, ValueToken}
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.LiftParser.*
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 
 import cats.Comonad
+import cats.data.NonEmptyList
 import cats.parse.Parser
 import cats.syntax.applicative.*
 import cats.syntax.comonad.*
@@ -18,10 +20,8 @@ import cats.~>
 
 case class ModuleExpr[F[_]](
   word: ModuleExpr.Word[F],
-  name: Ability[F],
-  declareAll: Option[Token[F]],
-  declareNames: List[Name[F]],
-  declareCustom: List[Ability[F]]
+  name: QName[F],
+  declares: Option[ModuleExpr.Declares[F]]
 ) extends HeaderExpr[F] {
   override def token: Token[F] = name
 
@@ -29,14 +29,31 @@ case class ModuleExpr[F[_]](
     copy(
       word = word.mapK(fk),
       name = name.mapK(fk),
-      declareAll = declareAll.map(_.mapK(fk)),
-      declareNames = declareNames.map(_.mapK(fk)),
-      declareCustom = declareCustom.map(_.mapK(fk))
+      declares = declares.map(_.mapK(fk))
     )
 }
 
 object ModuleExpr extends HeaderExpr.Companion {
 
+  enum Declares[F[_]] {
+    case All(point: Token[F])
+    case Names(names: NonEmptyList[QName[F]])
+
+    def mapK[K[_]: Comonad](fk: F ~> K): Declares[K] = this match {
+      case All(point) => All(point.mapK(fk))
+      case Names(names) => Names(names.map(_.mapK(fk)))
+    }
+  }
+
+  object Declares {
+
+    val p: Parser[Declares[Span.S]] =
+      (`declares` ~ ` *`) *> (
+        comma(QName.p).map(Names(_)) |
+          `star`.lift.map(Token.lift).map(All(_))
+      )
+  }
+
   final case class Word[F[_]: Comonad](
     token: F[Word.Kind]
   ) extends Token[F] {
@@ -60,49 +77,21 @@ object ModuleExpr extends HeaderExpr.Companion {
         case Kind.Aqua => aqua
       }
     }
-  }
 
-  type NameOrAb[F[_]] = Either[Name[F], Ability[F]]
-
-  private val nameOrAb: Parser[NameOrAb[Span.S]] =
-    Name.p.map(Left(_)) | Ability.ab.map(Right(_))
-
-  private val nameOrAbList: Parser[List[NameOrAb[Span.S]]] =
-    comma[NameOrAb[Span.S]](nameOrAb).map(_.toList)
-
-  private val nameOrAbListOrAll: Parser[Either[List[NameOrAb[Span.S]], Token[Span.S]]] =
-    nameOrAbList.map(Left(_)) | (`star` <* ` *`).lift.map(Token.lift(_)).map(Right(_))
-
-  private val moduleWord: Parser[Word[Span.S]] =
-    (`module`.as(Word.Kind.Module).lift.backtrack |
+    val p = (`module`.as(Word.Kind.Module).lift.backtrack |
       `aqua-word`.as(Word.Kind.Aqua).lift).map(Word(_))
+  }
 
   override val p: Parser[ModuleExpr[Span.S]] =
     (
-      (` *`.with1 *> moduleWord) ~
-        (` ` *> Ability.dotted) ~
-        (` declares ` *> nameOrAbListOrAll).backtrack
+      (` *`.with1 *> Word.p) ~
+        (` *` *> QName.p) ~
+        (` *` *> Declares.p <* ` *`).backtrack
           .map(_.some)
-          .orElse(` *`.as(none)) // Allow trailing spaces
-    ).map {
-      case ((word, name), None) =>
-        ModuleExpr(word, name, None, Nil, Nil)
-      case ((word, name), Some(Left(exportMembers))) =>
-        ModuleExpr(
-          word,
-          name,
-          None,
-          exportMembers.collect { case Left(x) => x },
-          exportMembers.collect { case Right(x) => x }
-        )
-      case ((word, name), Some(Right(point))) =>
-        ModuleExpr(
-          word,
-          name,
-          Some(point),
-          Nil,
-          Nil
-        )
+          // Allow trailing spaces without `declares`
+          .orElse(` *`.as(none))
+    ).map { case ((word, name), declares) =>
+      ModuleExpr(word, name, declares)
     }
 
 }

parser/src/main/scala/aqua/parser/head/UseExpr.scala

@@ -4,7 +4,7 @@ import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{Ability, LiteralToken, ValueToken}
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 
 import cats.Comonad
 import cats.parse.Parser
@@ -25,7 +25,7 @@ case class UseExpr[F[_]](
 object UseExpr extends HeaderExpr.Companion {
 
   override val p: Parser[HeaderExpr[Span.S]] =
-    (`use` *> ` ` *> ValueToken.string ~ (` as ` *> Ability.ab).?).map {
+    (`use` *> ` ` *> ValueToken.string ~ (` as ` *> Ability.dotted).?).map {
       case (filename, asModule) =>
         UseExpr(filename, asModule)
     }

parser/src/main/scala/aqua/parser/head/UseFromExpr.scala

@@ -4,7 +4,7 @@ import aqua.parser.lexer.Token.*
 import aqua.parser.lexer.{Ability, LiteralToken, Name, ValueToken}
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 
 import cats.Comonad
 import cats.data.NonEmptyList
@@ -27,9 +27,8 @@ case class UseFromExpr[F[_]](
 object UseFromExpr extends HeaderExpr.Companion {
 
   override val p: Parser[UseFromExpr[Span.S]] =
-    (`use` *> FromExpr.importFrom.surroundedBy(
-      ` `
-    ) ~ ValueToken.string ~ (` as ` *> Ability.ab)).map { case ((imports, filename), asModule) =>
+    (`use` *> FromExpr.importFrom.surroundedBy(` `) ~
+      ValueToken.string ~ (` as ` *> Ability.dotted)).map { case ((imports, filename), asModule) =>
       UseFromExpr(imports, filename, asModule)
     }
 }

parser/src/main/scala/aqua/parser/lexer/Ability.scala

@@ -3,13 +3,14 @@ package aqua.parser.lexer
 import aqua.parser.lexer.Token.*
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.LiftParser.*
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
+
 import cats.Comonad
 import cats.parse.Parser as P
-import cats.syntax.functor.*
 import cats.syntax.comonad.*
+import cats.syntax.functor.*
 import cats.~>
-import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
 
 case class Ability[F[_]: Comonad](name: F[String]) extends Token[F] {
   override def as[T](v: T): F[T] = name.as(v)

parser/src/main/scala/aqua/parser/lexer/Arg.scala

@@ -1,11 +1,12 @@
 package aqua.parser.lexer
 
 import aqua.parser.lift.LiftParser
-import cats.parse.{Parser => P}
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
+
 import Token._
 import cats.Comonad
-import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import cats.parse.{Parser => P}
 
 case class Arg[F[_]](name: Name[F], `type`: TypeToken[F])
 

parser/src/main/scala/aqua/parser/lexer/Name.scala

@@ -1,15 +1,16 @@
 package aqua.parser.lexer
 
-import aqua.parser.lexer.Token._
+import aqua.parser.lexer.Token.*
 import aqua.parser.lift.LiftParser
-import aqua.parser.lift.LiftParser._
+import aqua.parser.lift.LiftParser.*
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
+
 import cats.Comonad
 import cats.parse.{Parser => P}
-import cats.syntax.functor._
-import cats.syntax.comonad._
+import cats.syntax.comonad.*
+import cats.syntax.functor.*
 import cats.~>
-import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
 
 case class Name[F[_]: Comonad](name: F[String]) extends Token[F] {
   override def as[T](v: T): F[T] = name.as(v)

parser/src/main/scala/aqua/parser/lexer/PropertyOp.scala

@@ -6,7 +6,7 @@ import aqua.parser.lexer.Token.*
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.LiftParser.*
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 import aqua.types.LiteralType
 
 import cats.data.{NonEmptyList, NonEmptyMap}

parser/src/main/scala/aqua/parser/lexer/QName.scala

@@ -0,0 +1,55 @@
+package aqua.parser.lexer
+
+import aqua.helpers.data.PName
+import aqua.parser.lexer.Token.*
+import aqua.parser.lift.LiftParser
+import aqua.parser.lift.LiftParser.*
+import aqua.parser.lift.Span
+import aqua.parser.lift.Span.{given, *}
+
+import cats.Comonad
+import cats.arrow.FunctionK
+import cats.data.NonEmptyList
+import cats.parse.{Parser => P}
+import cats.syntax.comonad.*
+import cats.syntax.functor.*
+
+/**
+ * Qualified name. Name with parts separated by `.`
+ * e.g. `Some.Imported.Module.foo`
+ *
+ * @param name Name as a whole
+ * @param parts Parts of the name
+ */
+final case class QName[F[_]: Comonad](
+  name: F[String],
+  parts: NonEmptyList[F[String]]
+) extends Token[F] {
+
+  def value: String = name.extract
+  override def as[T](v: T): F[T] = name.as(v)
+
+  override def mapK[K[_]: Comonad](fk: FunctionK[F, K]): QName[K] =
+    copy(fk(name), parts.map(p => fk(p)))
+
+  def toPName: PName = PName(parts.map(_.extract))
+}
+
+object QName {
+
+  final case class As[F[_]: Comonad](
+    name: QName[F],
+    rename: Option[QName[F]]
+  )
+
+  val p: P[QName[Span.S]] =
+    anyName.lift
+      .repSep(`.`)
+      .withString
+      .lift
+      .map(span => {
+        val name = span.fmap { case (_, name) => name }
+        val parts = span.fmap { case (parts, _) => parts }.extract
+        QName(name, parts)
+      })
+}

parser/src/main/scala/aqua/parser/lexer/Token.scala

@@ -39,7 +39,6 @@ object Token {
   val `module`: P[Unit] = P.string("module")
   val `aqua-word`: P[Unit] = P.string("aqua")
   val `declares`: P[Unit] = P.string("declares")
-  val ` declares ` : P[Unit] = `declares`.surroundedBy(` `)
   val `declare`: P[Unit] = P.string("declare")
   val `_export`: P[Unit] = P.string("export")
   val `star`: P[Unit] = P.char('*')

parser/src/main/scala/aqua/parser/lexer/TypeToken.scala

@@ -4,7 +4,7 @@ import aqua.parser.lexer.Token.*
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.LiftParser.*
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan, S}
+import aqua.parser.lift.Span.{given, *}
 import aqua.types.ScalarType
 
 import cats.Comonad

parser/src/main/scala/aqua/parser/lexer/ValueToken.scala

@@ -6,7 +6,7 @@ import aqua.parser.lexer.Token.*
 import aqua.parser.lift.LiftParser
 import aqua.parser.lift.LiftParser.*
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan, S}
+import aqua.parser.lift.Span.{given, *}
 import aqua.types.LiteralType
 
 import cats.arrow.FunctionK

parser/src/main/scala/aqua/parser/lift/LiftParser.scala

@@ -13,25 +13,23 @@ trait LiftParser[S[_]] {
 
 object LiftParser {
 
-  implicit class LiftErrorOps[S[_]: LiftParser, T](e: Parser.Error) {
-    def wrapErr: S[Parser.Error] = implicitly[LiftParser[S]].wrapErr(e)
+  def apply[S[_]](using lp: LiftParser[S]): LiftParser[S] = lp
+
+  extension [S[_]: LiftParser, T](e: Parser.Error) {
+    def wrapErr: S[Parser.Error] = LiftParser[S].wrapErr(e)
   }
 
-  implicit class LiftParserOps[S[_]: LiftParser, T](parser: Parser[T]) {
-    def lift: Parser[S[T]] = implicitly[LiftParser[S]].lift(parser)
+  extension [S[_]: LiftParser, T](parser: Parser[T]) {
+    def lift: Parser[S[T]] = LiftParser[S].lift(parser)
   }
 
-  implicit class LiftParser0Ops[S[_]: LiftParser, T](parser0: Parser0[T]) {
-    def lift0: Parser0[S[T]] = implicitly[LiftParser[S]].lift0(parser0)
+  extension [S[_]: LiftParser, T](parser0: Parser0[T]) {
+    def lift0: Parser0[S[T]] = LiftParser[S].lift0(parser0)
   }
 
-  object Implicits {
-
-    implicit object idLiftParser extends LiftParser[Id] {
-      override def lift[T](p: Parser[T]): Parser[Id[T]] = p
-      override def lift0[T](p0: Parser0[T]): Parser0[Id[T]] = p0
-      override def wrapErr(e: Parser.Error): Id[Parser.Error] = e
-    }
-
+  given LiftParser[Id] with {
+    override def lift[T](p: Parser[T]): Parser[Id[T]] = p
+    override def lift0[T](p0: Parser0[T]): Parser0[Id[T]] = p0
+    override def wrapErr(e: Parser.Error): Id[Parser.Error] = e
   }
 }

parser/src/main/scala/aqua/parser/lift/Span.scala

@@ -1,8 +1,7 @@
 package aqua.parser.lift
 
 import cats.Comonad
-import cats.parse.{LocationMap, Parser0, Parser as P}
-
+import cats.parse.{LocationMap, Parser as P, Parser0}
 import scala.language.implicitConversions
 
 case class Span(startIndex: Int, endIndex: Int) {
@@ -131,7 +130,7 @@ object Span {
 
   type S[T] = (Span, T)
 
-  implicit object spanComonad extends Comonad[S] {
+  given Comonad[S] with {
     override def extract[A](x: S[A]): A = x._2
 
     override def coflatMap[A, B](fa: S[A])(f: S[A] ⇒ B): S[B] = fa.copy(_2 = f(fa))
@@ -139,15 +138,7 @@ object Span {
     override def map[A, B](fa: S[A])(f: A ⇒ B): S[B] = fa.copy(_2 = f(fa._2))
   }
 
-  implicit class PToSpan[T](p: P[T]) {
-    def lift: P[Span.S[T]] = Span.spanLiftParser.lift(p)
-  }
-
-  implicit class P0ToSpan[T](p: Parser0[T]) {
-    def lift0: Parser0[Span.S[T]] = Span.spanLiftParser.lift0(p)
-  }
-
-  implicit object spanLiftParser extends LiftParser[S] {
+  given LiftParser[S] with {
 
     override def lift[T](p: P[T]): P[S[T]] =
       (P.index.with1 ~ p ~ P.index).map { case ((s, v), e) ⇒

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

@@ -11,9 +11,9 @@ import aqua.parser.lexer.InfixToken.Op as InfixOp
 import aqua.parser.lexer.PrefixToken.Op.*
 import aqua.parser.lexer.PrefixToken.Op as PrefixOp
 import aqua.parser.lexer.Token.LiftToken
-import aqua.parser.lift.LiftParser.Implicits.idLiftParser
+import aqua.parser.lift.LiftParser.given
 import aqua.parser.lift.Span
-import aqua.parser.lift.Span.{P0ToSpan, PToSpan}
+import aqua.parser.lift.Span.{given, *}
 import aqua.types.LiteralType.{bool, number, signed, string, unsigned}
 import aqua.types.{LiteralType, ScalarType}
 
@@ -40,6 +40,11 @@ object AquaSpec {
 
   def toAb(str: String): Ability[Id] = Ability[Id](str)
 
+  def toQName(str: String): QName[Id] = QName[Id](
+    str,
+    NonEmptyList.fromListUnsafe(str.split("\\.").toList)
+  )
+
   def toVar(name: String): VarToken[Id] = VarToken[Id](toName(name))
 
   def toVarOp(name: Option[String]): Option[VarToken[Id]] =

parser/src/test/scala/aqua/parser/CoExprSpec.scala

@@ -4,14 +4,14 @@ import aqua.AquaSpec
 import aqua.AquaSpec.*
 import aqua.parser.expr.func.{CallArrowExpr, CoExpr, ForExpr, JoinExpr, OnExpr}
 import aqua.parser.lexer.{CallArrowToken, Token}
-import aqua.parser.lift.LiftParser.Implicits.idLiftParser
+import aqua.parser.lift.LiftParser.given
 
 import cats.data.{Chain, NonEmptyList}
 import cats.free.Cofree
 import cats.{Eval, Id}
+import org.scalatest.Inside
 import org.scalatest.flatspec.AnyFlatSpec
 import org.scalatest.matchers.should.Matchers
-import org.scalatest.Inside
 
 class CoExprSpec extends AnyFlatSpec with Matchers with Inside with AquaSpec {
 

parser/src/test/scala/aqua/parser/ParExprSpec.scala

@@ -4,14 +4,14 @@ import aqua.AquaSpec
 import aqua.AquaSpec.*
 import aqua.parser.expr.func.{CallArrowExpr, ForExpr, JoinExpr, OnExpr, ParExpr}
 import aqua.parser.lexer.{CallArrowToken, Token}
-import aqua.parser.lift.LiftParser.Implicits.idLiftParser
+import aqua.parser.lift.LiftParser.given
 
-import org.scalatest.flatspec.AnyFlatSpec
-import org.scalatest.matchers.should.Matchers
-import org.scalatest.Inside
-import cats.{Eval, Id}
 import cats.data.{Chain, NonEmptyList}
 import cats.free.Cofree
+import cats.{Eval, Id}
+import org.scalatest.Inside
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
 
 class ParExprSpec extends AnyFlatSpec with Matchers with Inside with AquaSpec {
 

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

@@ -3,8 +3,9 @@ package aqua.parser.head
 import aqua.AquaSpec
 import aqua.parser.expr.func.ServiceIdExpr
 import aqua.parser.lexer.{LiteralToken, Token}
-import aqua.parser.lift.LiftParser.Implicits.*
+import aqua.parser.lift.LiftParser.given
 import aqua.types.LiteralType
+
 import cats.Id
 import cats.data.NonEmptyList
 import org.scalatest.flatspec.AnyFlatSpec

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

@@ -3,7 +3,7 @@ package aqua.parser.head
 import aqua.AquaSpec
 import aqua.parser.expr.func.ServiceIdExpr
 import aqua.parser.lexer.{LiteralToken, Token}
-import aqua.parser.lift.LiftParser.Implicits.*
+import aqua.parser.lift.LiftParser.given
 import aqua.types.LiteralType
 
 import cats.Id

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

@@ -3,10 +3,11 @@ package aqua.parser.head
 import aqua.AquaSpec
 import aqua.parser.expr.func.ServiceIdExpr
 import aqua.parser.lexer.{LiteralToken, Token}
-import aqua.parser.lift.LiftParser.Implicits.*
+import aqua.parser.lift.LiftParser.given
 import aqua.types.LiteralType
 
 import cats.Id
+import cats.data.NonEmptyList
 import org.scalatest.flatspec.AnyFlatSpec
 import org.scalatest.matchers.should.Matchers
 
@@ -15,20 +16,17 @@ class ModuleSpec extends AnyFlatSpec with Matchers with AquaSpec {
 
   val myModule = ModuleExpr(
     ModuleExpr.Word[Id](Id(ModuleExpr.Word.Kind.Aqua)),
-    toAb("MyModule"),
-    None,
-    Nil,
-    Nil
+    toQName("MyModule"),
+    None
   )
 
   val declaresAll = myModule.copy(
-    declareAll = Some(Token.lift[Id, Unit](()))
+    declares = Some(ModuleExpr.Declares.All(Token.lift[Id, Unit](())))
   )
 
   def declares(symbols: List[String]) =
     myModule.copy(
-      declareNames = symbols.filter(_.headOption.exists(_.isLower)).map(toName),
-      declareCustom = symbols.filter(_.headOption.exists(_.isUpper)).map(toAb)
+      declares = Some(ModuleExpr.Declares.Names(NonEmptyList.fromListUnsafe(symbols.map(toQName))))
     )
 
   def parseModuleExpr(expr: String): ModuleExpr[Id] =

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

@@ -3,8 +3,9 @@ package aqua.parser.head
 import aqua.AquaSpec
 import aqua.parser.expr.func.ServiceIdExpr
 import aqua.parser.lexer.{LiteralToken, Token}
-import aqua.parser.lift.LiftParser.Implicits.*
+import aqua.parser.lift.LiftParser.given
 import aqua.types.LiteralType
+
 import cats.Id
 import cats.data.NonEmptyList
 import org.scalatest.flatspec.AnyFlatSpec

parser/src/test/scala/aqua/parser/lexer/PropertyOpSpec.scala

@@ -1,7 +1,8 @@
 package aqua.parser.lexer
 
-import aqua.parser.lift.LiftParser.Implicits.idLiftParser
+import aqua.parser.lift.LiftParser.given
 import aqua.types.LiteralType
+
 import cats.Id
 import cats.data.{NonEmptyList, NonEmptyMap}
 import org.scalatest.EitherValues

parser/src/test/scala/aqua/parser/lexer/TypeTokenSpec.scala

@@ -1,6 +1,6 @@
 package aqua.parser.lexer
 
-import aqua.parser.lift.LiftParser.Implicits.idLiftParser
+import aqua.parser.lift.LiftParser.given
 import aqua.types.ScalarType
 
 import cats.Id

parser/src/test/scala/aqua/parser/lexer/ValueTokenSpec.scala

@@ -1,13 +1,13 @@
 package aqua.parser.lexer
 
-import org.scalatest.EitherValues
-import org.scalatest.flatspec.AnyFlatSpec
-import org.scalatest.matchers.should.Matchers
-import aqua.parser.lift.LiftParser.Implicits.idLiftParser
+import aqua.parser.lift.LiftParser.given
 import aqua.types.LiteralType
 
 import cats.Id
 import cats.data.NonEmptyList
+import org.scalatest.EitherValues
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
 
 class ValueTokenSpec extends AnyFlatSpec with Matchers with EitherValues {
 

parser/src/test/scala/aqua/parser/lexer/VarLambdaSpec.scala

@@ -1,6 +1,7 @@
 package aqua.parser.lexer
 
-import aqua.parser.lift.LiftParser.Implicits.idLiftParser
+import aqua.parser.lift.LiftParser.given
+
 import cats.Id
 import cats.data.NonEmptyList
 import org.scalatest.EitherValues

semantics/src/main/scala/aqua/semantics/header/HeaderSem.scala

@@ -23,8 +23,8 @@ case class HeaderSem[S[_], C](
 
 object HeaderSem {
 
-  def fromInit[S[_], C](init: C): HeaderSem[S, C] =
-    HeaderSem(init, c => c.validNec)
+  def fromInit[S[_], C: Monoid](init: C): HeaderSem[S, C] =
+    HeaderSem(init, _ => Monoid[C].empty.validNec)
 
   given [S[_]: Comonad, C](using
     rc: Monoid[C]

semantics/src/main/scala/aqua/semantics/header/ModuleSem.scala

@@ -1,5 +1,6 @@
 package aqua.semantics.header
 
+import aqua.helpers.data.PName
 import aqua.parser.head.ModuleExpr
 import aqua.semantics.header.HeaderHandler.{Res, error}
 import aqua.semantics.header.Picker.*
@@ -19,40 +20,41 @@ class ModuleSem[S[_]: Comonad, C: Picker](expr: ModuleExpr[S])(using
   locations: LocationsAlgebra[S, State[C, *]]
 ) {
 
-  import expr.*
-
   def headerSem: Res[S, C] = {
     lazy val sem = HeaderSem(
       // Save module header info
-      Picker[C].blank.setModule(name.value),
+      Picker[C].blank.setModule(expr.name.value.some),
       ctx =>
-        // When file is handled, check that all the declarations exists
-        if (declareAll.nonEmpty) ctx.setDeclares(ctx.allNames).validNec
-        else {
-          val declares = declareNames.fproductLeft(_.value) ::: declareCustom.fproductLeft(_.value)
-          val names = declares.map { case (name, _) => name }.toSet
-          val res = ctx.setDeclares(names).addOccurences(declares)
+        expr.declares match {
+          case None => ctx.validNec
+          case Some(ModuleExpr.Declares.All(_)) =>
+            val names = ctx.allNames.map(PName.simpleUnsafe).toSet
+            ctx.setDeclares(names).validNec
+          case Some(ModuleExpr.Declares.Names(declareNames)) =>
+            val declares = declareNames.fproductLeft(_.value).toList
+            val names = declareNames.map(_.toPName).toList.toSet
+            val res = ctx.setDeclares(names).addOccurences(declares)
 
-          // summarize contexts to allow redeclaration of imports
-          declares.map { case (n, t) =>
-            res
-              .pick(n, None, ctx.module.nonEmpty)
-              .toValidNec(
-                error(
-                  t,
-                  s"`$n` is expected to be declared, but declaration is not found in the file"
+            // summarize contexts to allow redeclaration of imports
+            declares.map { case (n, t) =>
+              res
+                .pick(t.toPName, ctx.module.nonEmpty)
+                .toValidNec(
+                  error(
+                    t,
+                    s"`$n` is expected to be declared, but declaration is not found in the file"
+                  )
                 )
-              )
-              .void
-          // TODO: Should not it be possible to make `.combineAll` the final result?
-          // Seems like `.pick` does not return much information
-          }.combineAll.as(res)
+                .void
+            // TODO: Should not it be possible to make `.combineAll` the final result?
+            // Seems like `.pick` does not return much information
+            }.combineAll.as(res)
         }
     )
 
-    word.value.fold(
+    expr.word.value.fold(
       module = error(
-        word,
+        expr.word,
         "Keyword `module` is deprecated, use `aqua` instead"
       ).invalidNec,
       aqua = sem.validNec

semantics/src/main/scala/aqua/semantics/header/Picker.scala

@@ -1,5 +1,6 @@
 package aqua.semantics.header
 
+import aqua.helpers.data.PName
 import aqua.raw.{RawContext, RawPart}
 import aqua.types.{AbilityType, ArrowType, Type}
 
@@ -13,6 +14,7 @@ trait Picker[A] {
   def definedAbilityNames(ctx: A): Set[String]
   def blank: A
   def pick(ctx: A, name: String, rename: Option[String], declared: Boolean): Option[A]
+  def pick(ctx: A, name: PName, declared: Boolean): Option[A]
   def pickDeclared(ctx: A): A
   def pickHeader(ctx: A): A
   def module(ctx: A): Option[String]
@@ -24,8 +26,8 @@ trait Picker[A] {
   def funcAcceptAbility(ctx: A, name: String): Boolean
   def setAbility(ctx: A, name: String, ctxAb: A): A
   def setImportPaths(ctx: A, importPaths: Map[String, String]): A
-  def setModule(ctx: A, name: String): A
-  def setDeclares(ctx: A, declares: Set[String]): A
+  def setModule(ctx: A, name: Option[String]): A
+  def setDeclares(ctx: A, declares: Set[PName]): A
   def setExports(ctx: A, exports: Map[String, Option[String]]): A
   def addPart(ctx: A, part: (A, RawPart)): A
 }
@@ -41,6 +43,10 @@ object Picker {
 
     def pick(name: String, rename: Option[String], declared: Boolean): Option[A] =
       Picker[A].pick(p, name, rename, declared)
+
+    def pick(name: PName, declared: Boolean): Option[A] =
+      Picker[A].pick(p, name, declared)
+
     def pickDeclared: A = Picker[A].pickDeclared(p)
     def pickHeader: A = Picker[A].pickHeader(p)
     def module: Option[String] = Picker[A].module(p)
@@ -65,10 +71,10 @@ object Picker {
     def addFreeParts(parts: List[RawPart]): A =
       parts.foldLeft(p) { case (ctx, part) => ctx.addPart(blank -> part) }
 
-    def setModule(name: String): A =
+    def setModule(name: Option[String]): A =
       Picker[A].setModule(p, name)
 
-    def setDeclares(declares: Set[String]): A =
+    def setDeclares(declares: Set[PName]): A =
       Picker[A].setDeclares(p, declares)
 
     def setExports(exports: Map[String, Option[String]]): A =
@@ -130,10 +136,10 @@ object Picker {
     override def setImportPaths(ctx: RawContext, importPaths: Map[String, String]): RawContext =
       ctx
 
-    override def setModule(ctx: RawContext, name: String): RawContext =
-      ctx.copy(module = Some(name))
+    override def setModule(ctx: RawContext, name: Option[String]): RawContext =
+      ctx.copy(module = name)
 
-    override def setDeclares(ctx: RawContext, declares: Set[String]): RawContext =
+    override def setDeclares(ctx: RawContext, declares: Set[PName]): RawContext =
       ctx.copy(declares = declares)
 
     override def setExports(ctx: RawContext, exports: Map[String, Option[String]]): RawContext =
@@ -146,13 +152,39 @@ object Picker {
       declared: Boolean
     ): Option[RawContext] =
       Option
-        .when(!declared || ctx.declares(name)) {
-          RawContext.blank
-            .copy(parts = ctx.parts.filter(_._2.name == name).map { case (partContext, part) =>
-              (partContext, rename.fold(part)(part.rename))
-            })
+        .when(!declared || ctx.declaredNames(name)) {
+          RawContext.fromParts(
+            ctx.parts.collect {
+              case (partContext, part) if part.name == name =>
+                (partContext, rename.fold(part)(part.rename))
+            }
+          )
         }
         .filter(_.nonEmpty)
+        .map(
+          // Module and declares should not be lost when picking
+          // Because it affects later logic
+          _.setModule(ctx.module).setDeclares(Set(PName.simpleUnsafe(name)))
+        )
+
+    override def pick(
+      ctx: RawContext,
+      name: PName,
+      declared: Boolean
+    ): Option[RawContext] =
+      name.simple.fold(
+        name.splits.collectFirstSome { case (ab, field) =>
+          for {
+            ability <- ctx.abilities.get(ab.value)
+            inner <- pick(ability, field, declared)
+          } yield RawContext
+            .fromAbilities(Map(ab.value -> inner))
+            // Module and declares should not be lost when picking
+            // Because it affects later logic
+            .setModule(ctx.module)
+            .setDeclares(Set(name))
+        }
+      )(pick(ctx, _, None, declared))
 
     override def pickHeader(ctx: RawContext): RawContext =
       RawContext.blank.copy(module = ctx.module, declares = ctx.declares, exports = ctx.exports)
@@ -161,7 +193,7 @@ object Picker {
       if (ctx.module.isEmpty) ctx
       else
         ctx.declares.toList
-          .flatMap(n => pick(ctx, n, None, ctx.module.nonEmpty))
+          .flatMap(n => pick(ctx, n, ctx.module.nonEmpty))
           .foldLeft(pickHeader(ctx))(_ |+| _)
   }
 

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

@@ -154,7 +154,12 @@ class ValuesAlgebra[S[_], Alg[_]: Monad](using
           .filterF(nv => T.resolveType(nv.typeName, mustBeDefined = false).map(_.isDefined))
           .widen[ValueToken[S]]
 
-        callArrow.orElse(ability).orElse(namedValue).foldF(default)(valueToRaw)
+        callArrow
+          .orElse(ability)
+          .orElse(namedValue)
+          .foldF(default)(
+            valueToRaw
+          )
 
       case dvt @ NamedValueToken(typeName, fields) =>
         (for {

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

@@ -13,8 +13,8 @@ import aqua.types.ArrowType
 import cats.data.*
 import cats.syntax.applicative.*
 import cats.syntax.apply.*
-import cats.syntax.functor.*
 import cats.syntax.flatMap.*
+import cats.syntax.functor.*
 import cats.syntax.option.*
 import monocle.Lens
 import monocle.macros.GenLens

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

@@ -66,6 +66,6 @@ object AbilitiesState {
       rootServiceIds = context.allServices.flatMap { case (name, service) =>
         service.defaultId.map(name -> _)
       },
-      abilities = context.abilities // TODO is it the right way to collect abilities? Why?
+      abilities = context.allAbilities
     )
 }

semantics/src/test/scala/aqua/semantics/HeaderSpec.scala

@@ -2,6 +2,7 @@ package aqua.semantics
 
 import aqua.parser.Ast
 import aqua.parser.head.{ExportExpr, FromExpr, HeaderExpr, ModuleExpr}
+import aqua.parser.lexer.QName
 import aqua.parser.lexer.Token
 import aqua.parser.lexer.{Ability, Name}
 import aqua.raw.RawContext
@@ -38,11 +39,9 @@ class HeaderSpec extends AnyFlatSpec with Matchers with Inside {
       Token.lift(()),
       Chain(
         ModuleExpr(
-          word = ModuleExpr.Word[Id](Id(ModuleExpr.Word.Kind.Aqua)),
-          name = Ability[Id]("TestModule"),
-          declareAll = None,
-          declareNames = Nil,
-          declareCustom = Nil
+          word = ModuleExpr.Word(ModuleExpr.Word.Kind.Aqua),
+          name = QName("TestModule", NonEmptyList.one("TestModule")),
+          declares = None
         ),
         ExportExpr(NonEmptyList.of(exp))
       )

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

@@ -28,7 +28,6 @@ class SemanticsSpec extends AnyFlatSpec with Matchers with Inside {
 
   val emptyCall = Call(Nil, Nil)
 
-  implicit val fileLift: LiftParser[Span.S] = Span.spanLiftParser
   val parser = Parser.parse(Parser.spanParser)
 
   val semantics = new RawSemantics[Span.S]()

utils/helpers/src/main/scala/aqua/helpers/data/PName.scala

@@ -0,0 +1,39 @@
+package aqua.helpers.data
+
+import aqua.errors.Errors.internalError
+
+import cats.data.NonEmptyList
+import cats.syntax.option.*
+
+/**
+ * Short for PathName. Represents name with parts separated by `.`
+ */
+final case class PName(
+  parts: NonEmptyList[String]
+) {
+
+  lazy val simple: Option[String] =
+    Option.when(parts.length == 1)(parts.head)
+
+  lazy val isSimple: Boolean = simple.isDefined
+
+  lazy val value: String = parts.toList.mkString(".")
+
+  lazy val splits: List[(PName, PName)] = {
+    val partsList = parts.toList
+    (1 until parts.length).toList.map(i =>
+      PName(NonEmptyList.fromListUnsafe(partsList.take(i))) ->
+        PName(NonEmptyList.fromListUnsafe(partsList.drop(i)))
+    )
+  }
+
+  override def toString(): String = value
+}
+
+object PName {
+
+  def simpleUnsafe(name: String): PName =
+    if (name.isEmpty || name.contains("."))
+      internalError(s"Invalid PName: $name")
+    else PName(NonEmptyList.one(name))
+}