diff --git a/engine/runtime-parser/src/main/java/org/enso/compiler/core/IR.java b/engine/runtime-parser/src/main/java/org/enso/compiler/core/IR.java
index 09efe7255c9d..f0fcf58f0ed2 100644
--- a/engine/runtime-parser/src/main/java/org/enso/compiler/core/IR.java
+++ b/engine/runtime-parser/src/main/java/org/enso/compiler/core/IR.java
@@ -80,7 +80,7 @@ default List<IR> preorder() {
     List<IR> ordered = children().flatMap(c -> c.preorder());
     IR element = this;
     return $colon$colon$.MODULE$.apply(
-        element, ordered); // ordered.prepended(element) is reporeted as ambiguous
+        element, ordered); // ordered.prepended(element) is reported as ambiguous
   }
 
   /**
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/CallArgument.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/CallArgument.scala
index 56282daf46fa..d9929426643d 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/CallArgument.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/CallArgument.scala
@@ -138,7 +138,7 @@ object CallArgument {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] =
+    override lazy val children: List[IR] =
       name.map(List(_, value)).getOrElse(List(value))
 
     /** @inheritdoc */
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/DefinitionArgument.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/DefinitionArgument.scala
index 4c83865c9376..f71215af4fcf 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/DefinitionArgument.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/DefinitionArgument.scala
@@ -174,7 +174,7 @@ object DefinitionArgument {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] =
+    override lazy val children: List[IR] =
       name :: ascribedType.toList ++ defaultValue.toList
 
     /** @inheritdoc */
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Empty.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Empty.scala
index 068a0831c864..1ba33f7cc85f 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Empty.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Empty.scala
@@ -76,7 +76,7 @@ sealed case class Empty(
        |""".toSingleLine
 
   /** @inheritdoc */
-  override def children: List[IR] = List()
+  override def children: List[IR] = Nil
 
   /** @inheritdoc */
   override def showCode(indent: Int): String = "IR.Empty"
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Expression.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Expression.scala
index 0c01efe1615b..e008d360893a 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Expression.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Expression.scala
@@ -157,7 +157,7 @@ object Expression {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = expressions :+ returnValue
+    override lazy val children: List[IR] = expressions :+ returnValue
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = {
@@ -268,7 +268,7 @@ object Expression {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(name, expression)
+    override lazy val children: List[IR] = List(name, expression)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Function.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Function.scala
index 1f83839a8a13..5cc667c57dc3 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Function.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Function.scala
@@ -169,7 +169,7 @@ object Function {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = arguments :+ body
+    override lazy val children: List[IR] = arguments :+ body
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = {
@@ -336,7 +336,7 @@ object Function {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = (name :: arguments) :+ body
+    override lazy val children: List[IR] = (name :: arguments) :+ body
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = {
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Literal.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Literal.scala
index 187c2a1a5a75..ba8b31cd27a3 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Literal.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Literal.scala
@@ -105,7 +105,7 @@ object Literal {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List()
+    override def children: List[IR] = Nil
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = if (this.base.isDefined) {
@@ -230,7 +230,7 @@ object Literal {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List()
+    override def children: List[IR] = Nil
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = s""""$text""""
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Module.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Module.scala
index 1740fdfd1877..bf70227b6875 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Module.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Module.scala
@@ -113,7 +113,7 @@ final case class Module(
   }
 
   /** @inheritdoc */
-  override def children: List[IR] = imports ++ exports ++ bindings
+  override lazy val children: List[IR] = imports ++ exports ++ bindings
 
   /** String representation. */
   override def toString: String =
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Name.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Name.scala
index 815ccca1ce6d..69c55919af02 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Name.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Name.scala
@@ -145,7 +145,7 @@ object Name {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] =
+    override lazy val children: List[IR] =
       typePointer.map(_ :: methodName :: Nil).getOrElse(methodName :: Nil)
 
     /** @inheritdoc */
@@ -353,7 +353,7 @@ object Name {
          |""".stripMargin
 
     /** @inheritdoc */
-    override def children: List[IR] = List()
+    override def children: List[IR] = Nil
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = "_"
@@ -423,7 +423,7 @@ object Name {
          |)
          |""".stripMargin
 
-    override def children: List[IR] = List()
+    override def children: List[IR] = Nil
 
     override def showCode(indent: Int): String = name
   }
@@ -526,7 +526,7 @@ object Name {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List()
+    override def children: List[IR] = Nil
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = name
@@ -630,7 +630,7 @@ object Name {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List()
+    override def children: List[IR] = Nil
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = s"@$name"
@@ -719,7 +719,7 @@ object Name {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(expression)
+    override lazy val children: List[IR] = List(expression)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
@@ -799,7 +799,7 @@ object Name {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List()
+    override def children: List[IR] = Nil
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = name
@@ -875,7 +875,7 @@ object Name {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List()
+    override def children: List[IR] = Nil
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = name
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Pattern.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Pattern.scala
index 3e58a44c0775..d160ffeeb5bc 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Pattern.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Pattern.scala
@@ -115,7 +115,7 @@ object Pattern {
       copy(location = location)
 
     /** @inheritdoc */
-    override def children: List[IR] = List(name)
+    override lazy val children: List[IR] = List(name)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = name.showCode(indent)
@@ -264,7 +264,7 @@ object Pattern {
     ): Constructor = copy(location = location)
 
     /** @inheritdoc */
-    override def children: List[IR] = constructor :: fields
+    override lazy val children: List[IR] = constructor :: fields
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = {
@@ -359,7 +359,7 @@ object Pattern {
       copy(location = location)
 
     /** @inheritdoc */
-    override def children: List[IR] = List(literal)
+    override lazy val children: List[IR] = List(literal)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = literal.showCode(indent)
@@ -463,7 +463,7 @@ object Pattern {
       copy(location = location)
 
     /** @inheritdoc */
-    override def children: List[IR] = List(name, tpe)
+    override lazy val children: List[IR] = List(name, tpe)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Type.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Type.scala
index 57ddba922382..ea349c3d3c70 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Type.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/Type.scala
@@ -110,7 +110,7 @@ object Type {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = args :+ result
+    override lazy val children: List[IR] = args :+ result
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
@@ -218,7 +218,7 @@ object Type {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(typed, signature)
+    override lazy val children: List[IR] = List(typed, signature)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
@@ -323,7 +323,7 @@ object Type {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(typed, context)
+    override lazy val children: List[IR] = List(typed, context)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
@@ -426,7 +426,7 @@ object Type {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(typed, error)
+    override lazy val children: List[IR] = List(typed, error)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Application.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Application.scala
index c76e7a882299..66ff48cd8f38 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Application.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Application.scala
@@ -123,7 +123,7 @@ object Application {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = function :: arguments
+    override lazy val children: List[IR] = function :: arguments
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = {
@@ -216,7 +216,7 @@ object Application {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(target)
+    override lazy val children: List[IR] = List(target)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
@@ -328,8 +328,8 @@ object Application {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] =
-      expression.map(List(_)).getOrElse(List())
+    override lazy val children: List[IR] =
+      expression.map(List(_)).getOrElse(Nil)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = {
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Case.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Case.scala
index 3015c653ac35..0d64fa5e6d82 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Case.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Case.scala
@@ -145,7 +145,7 @@ object Case {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = scrutinee :: branches.toList
+    override lazy val children: List[IR] = scrutinee :: branches.toList
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = {
@@ -298,7 +298,7 @@ object Case {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(pattern, expression)
+    override lazy val children: List[IR] = List(pattern, expression)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = {
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Comment.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Comment.scala
index 656383dfab09..af7755007916 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Comment.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Comment.scala
@@ -104,7 +104,7 @@ object Comment {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List()
+    override def children: List[IR] = Nil
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Error.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Error.scala
index b905642a06f8..c4f46ed13593 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Error.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Error.scala
@@ -111,7 +111,7 @@ object Error {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(ir)
+    override lazy val children: List[IR] = List(ir)
 
     /** @inheritdoc */
     override def message(source: (IdentifiedLocation => String)): String =
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Foreign.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Foreign.scala
index be507596a7cb..cd47d7db10db 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Foreign.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Foreign.scala
@@ -113,7 +113,7 @@ object Foreign {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List()
+    override def children: List[IR] = Nil
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = "FOREIGN DEF"
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Operator.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Operator.scala
index 7fc4487b22e5..b05d4474d884 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Operator.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Operator.scala
@@ -134,7 +134,7 @@ object Operator {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(left, operator, right)
+    override lazy val children: List[IR] = List(left, operator, right)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = {
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Section.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Section.scala
index c127b07ce991..82a314f898a2 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Section.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/Section.scala
@@ -125,7 +125,7 @@ object Section {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(arg, operator)
+    override lazy val children: List[IR] = List(arg, operator)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
@@ -216,7 +216,7 @@ object Section {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(operator)
+    override lazy val children: List[IR] = List(operator)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
@@ -322,7 +322,7 @@ object Section {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(operator, arg)
+    override lazy val children: List[IR] = List(operator, arg)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Conversion.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Conversion.scala
index 219e0ef5b4a5..8c9ad0484806 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Conversion.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Conversion.scala
@@ -80,7 +80,7 @@ sealed case class Conversion(
   }
 
   /** @inheritdoc */
-  override def children: List[IR] = List(storedIr)
+  override lazy val children: List[IR] = List(storedIr)
 
   /** @inheritdoc */
   override def showCode(indent: Int): String =
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/ImportExport.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/ImportExport.scala
index dc0c9b157295..187849c36f88 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/ImportExport.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/ImportExport.scala
@@ -92,7 +92,7 @@ sealed case class ImportExport(
        |""".toSingleLine
 
   /** @inheritdoc */
-  override def children: List[IR] = List(ir)
+  override lazy val children: List[IR] = List(ir)
 
   /** @inheritdoc */
   override def message(source: (IdentifiedLocation => String)): String =
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Pattern.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Pattern.scala
index bced8e4cfae8..8f7c3a9208ab 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Pattern.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Pattern.scala
@@ -82,7 +82,7 @@ sealed case class Pattern(
   override val location: Option[IdentifiedLocation] =
     originalPattern.location
 
-  override def children: List[IR] = List(originalPattern)
+  override lazy val children: List[IR] = List(originalPattern)
 
   override def showCode(indent: Int): String =
     originalPattern.showCode(indent)
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Redefined.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Redefined.scala
index c1f82aa75fb6..22fb6ae4b8f1 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Redefined.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Redefined.scala
@@ -101,7 +101,7 @@ object Redefined {
     override def diagnosticKeys(): Array[Any] = Array()
 
     /** @inheritdoc */
-    override def children: List[IR] = List()
+    override def children: List[IR] = Nil
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = "(Redefined This_Arg)"
@@ -223,7 +223,7 @@ object Redefined {
          |""".stripMargin
 
     /** @inheritdoc */
-    override def children: List[IR] =
+    override lazy val children: List[IR] =
       targetType
         .map(_ :: sourceType :: Nil)
         .getOrElse(sourceType :: Nil)
@@ -346,7 +346,7 @@ object Redefined {
          |""".stripMargin
 
     /** @inheritdoc */
-    override def children: List[IR] =
+    override lazy val children: List[IR] =
       typeName
         .map(_ :: methodName :: Nil)
         .getOrElse(methodName :: Nil)
@@ -472,7 +472,7 @@ object Redefined {
          |""".stripMargin
 
     /** @inheritdoc */
-    override def children: List[IR] = List(atomName, methodName)
+    override lazy val children: List[IR] = List(atomName, methodName)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
@@ -573,7 +573,7 @@ object Redefined {
          |""".stripMargin
 
     /** @inheritdoc */
-    override def children: List[IR] = List(typeName)
+    override lazy val children: List[IR] = List(typeName)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
@@ -674,7 +674,7 @@ object Redefined {
          |""".stripMargin
 
     /** @inheritdoc */
-    override def children: List[IR] = List(name)
+    override lazy val children: List[IR] = List(name)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
@@ -768,7 +768,7 @@ object Redefined {
          |""".stripMargin
 
     /** @inheritdoc */
-    override def children: List[IR] = List(invalidBinding)
+    override lazy val children: List[IR] = List(invalidBinding)
 
     /** @inheritdoc */
     override def message(source: (IdentifiedLocation => String)): String =
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Resolution.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Resolution.scala
index 6466f5cbb64d..4e5ccbf6c976 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Resolution.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Resolution.scala
@@ -79,7 +79,7 @@ sealed case class Resolution(
     )
 
   /** @inheritdoc */
-  override def children: List[IR] = List(originalName)
+  override lazy val children: List[IR] = List(originalName)
 
   /** @inheritdoc */
   override def showCode(indent: Int): String = originalName.showCode(indent)
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Syntax.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Syntax.scala
index 7a4f429dc07b..af492bce4284 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Syntax.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Syntax.scala
@@ -90,7 +90,7 @@ sealed case class Syntax(
        |""".toSingleLine
 
   /** @inheritdoc */
-  override def children: List[IR] = List()
+  override def children: List[IR] = Nil
 
   /** @inheritdoc */
   override def message(source: (IdentifiedLocation => String)): String =
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Unexpected.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Unexpected.scala
index 35e29bbcfa7d..b2c39286fc3c 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Unexpected.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/expression/errors/Unexpected.scala
@@ -111,7 +111,7 @@ object Unexpected {
       )
 
     /** @inheritdoc */
-    override def children: List[IR] = List(ir)
+    override lazy val children: List[IR] = List(ir)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/Definition.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/Definition.scala
index 30d5be4745aa..f3edf698bbb8 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/Definition.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/Definition.scala
@@ -139,7 +139,7 @@ object Definition {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = name :: (params :++ members)
+    override lazy val children: List[IR] = name :: (params :++ members)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = {
@@ -264,7 +264,7 @@ object Definition {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = name :: arguments ::: annotations
+    override lazy val children: List[IR] = name :: arguments ::: annotations
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = {
@@ -391,7 +391,7 @@ object Definition {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = (name :: arguments) ::: body
+    override lazy val children: List[IR] = (name :: arguments) ::: body
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = {
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/Export.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/Export.scala
index 977566da57f4..7f64a1c755e3 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/Export.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/Export.scala
@@ -149,7 +149,7 @@ object Export {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] =
+    override lazy val children: List[IR] =
       name :: List(
         rename.toList,
         onlyNames.getOrElse(List()),
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/Import.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/Import.scala
index 8d196938ee99..1674df6503e8 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/Import.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/Import.scala
@@ -164,7 +164,7 @@ object Import {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] =
+    override lazy val children: List[IR] =
       name :: List(
         rename.toList,
         onlyNames.getOrElse(List()),
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/definition/Method.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/definition/Method.scala
index 657b2b85092a..7e0667332e15 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/definition/Method.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/definition/Method.scala
@@ -177,7 +177,7 @@ object Method {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(methodReference, body)
+    override lazy val children: List[IR] = List(methodReference, body)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = {
@@ -357,7 +357,7 @@ object Method {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] =
+    override lazy val children: List[IR] =
       (methodReference :: arguments) :+ body
 
     /** @inheritdoc */
@@ -500,7 +500,7 @@ object Method {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] =
+    override lazy val children: List[IR] =
       List(methodReference, sourceTypeName, body)
 
     /** @inheritdoc */
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/imports/Polyglot.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/imports/Polyglot.scala
index 66ce8d6e1c79..54cf2069465a 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/imports/Polyglot.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/module/scope/imports/Polyglot.scala
@@ -105,7 +105,7 @@ sealed case class Polyglot(
        |""".toSingleLine
 
   /** @inheritdoc */
-  override def children: List[IR] = List()
+  override def children: List[IR] = Nil
 
   /** @inheritdoc */
   override def showCode(indent: Int): String = {
diff --git a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/type/Set.scala b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/type/Set.scala
index c7af7e98a230..44fd3ba0c443 100644
--- a/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/type/Set.scala
+++ b/engine/runtime-parser/src/main/scala/org/enso/compiler/core/ir/type/Set.scala
@@ -141,7 +141,7 @@ object Set {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(label, memberType, value)
+    override lazy val children: List[IR] = List(label, memberType, value)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String = {
@@ -249,7 +249,7 @@ object Set {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(left, right)
+    override lazy val children: List[IR] = List(left, right)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
@@ -354,7 +354,7 @@ object Set {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(left, right)
+    override lazy val children: List[IR] = List(left, right)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
@@ -458,7 +458,7 @@ object Set {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(left, right)
+    override lazy val children: List[IR] = List(left, right)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
@@ -554,7 +554,7 @@ object Set {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = operands.toList
+    override def children: List[IR] = operands
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =
@@ -659,7 +659,7 @@ object Set {
          |""".toSingleLine
 
     /** @inheritdoc */
-    override def children: List[IR] = List(left, right)
+    override lazy val children: List[IR] = List(left, right)
 
     /** @inheritdoc */
     override def showCode(indent: Int): String =