diff --git a/swift/ql/lib/codeql/swift/elements/decl/ClassOrStructDeclImpl.qll b/swift/ql/lib/codeql/swift/elements/decl/ClassOrStructDecl.qll
similarity index 89%
rename from swift/ql/lib/codeql/swift/elements/decl/ClassOrStructDeclImpl.qll
rename to swift/ql/lib/codeql/swift/elements/decl/ClassOrStructDecl.qll
index 37c3935a17f83..e252c70ec8ced 100644
--- a/swift/ql/lib/codeql/swift/elements/decl/ClassOrStructDeclImpl.qll
+++ b/swift/ql/lib/codeql/swift/elements/decl/ClassOrStructDecl.qll
@@ -14,7 +14,7 @@ private import codeql.swift.elements.decl.NominalTypeDecl
  * }
  * ```
  */
-class ClassOrStructDecl extends NominalTypeDecl {
+final class ClassOrStructDecl extends NominalTypeDecl {
   ClassOrStructDecl() {
     this instanceof ClassDecl
     or
diff --git a/swift/ql/lib/codeql/swift/elements/decl/MethodImpl.qll b/swift/ql/lib/codeql/swift/elements/decl/Method.qll
similarity index 97%
rename from swift/ql/lib/codeql/swift/elements/decl/MethodImpl.qll
rename to swift/ql/lib/codeql/swift/elements/decl/Method.qll
index cfaa635f6b624..c271eb6398b97 100644
--- a/swift/ql/lib/codeql/swift/elements/decl/MethodImpl.qll
+++ b/swift/ql/lib/codeql/swift/elements/decl/Method.qll
@@ -12,7 +12,7 @@ private Decl getAMember(Decl ctx) {
 /**
  * A function that is a member of a class, struct, enum or protocol.
  */
-class Method extends Function {
+final class Method extends Function {
   Method() {
     this = getAMember(any(ClassDecl c))
     or
diff --git a/swift/ql/lib/codeql/swift/elements/expr/ArithmeticOperationImpl.qll b/swift/ql/lib/codeql/swift/elements/expr/ArithmeticOperation.qll
similarity index 80%
rename from swift/ql/lib/codeql/swift/elements/expr/ArithmeticOperationImpl.qll
rename to swift/ql/lib/codeql/swift/elements/expr/ArithmeticOperation.qll
index b921e948c343d..1639555cd3c38 100644
--- a/swift/ql/lib/codeql/swift/elements/expr/ArithmeticOperationImpl.qll
+++ b/swift/ql/lib/codeql/swift/elements/expr/ArithmeticOperation.qll
@@ -9,7 +9,7 @@ private import codeql.swift.elements.expr.DotSyntaxCallExpr
  * a + b
  * ```
  */
-class ArithmeticOperation extends Expr {
+final class ArithmeticOperation extends Expr {
   ArithmeticOperation() {
     this instanceof BinaryArithmeticOperation or
     this instanceof UnaryArithmeticOperation
@@ -31,7 +31,7 @@ class ArithmeticOperation extends Expr {
  * a + b
  * ```
  */
-class BinaryArithmeticOperation extends BinaryExpr {
+final class BinaryArithmeticOperation extends BinaryExpr {
   BinaryArithmeticOperation() {
     this instanceof AddExpr or
     this instanceof SubExpr or
@@ -48,7 +48,7 @@ class BinaryArithmeticOperation extends BinaryExpr {
  * a &+ b
  * ```
  */
-class AddExpr extends BinaryExpr {
+final class AddExpr extends BinaryExpr {
   AddExpr() { this.getStaticTarget().getName() = ["+(_:_:)", "&+(_:_:)"] }
 }
 
@@ -59,7 +59,7 @@ class AddExpr extends BinaryExpr {
  * a &- b
  * ```
  */
-class SubExpr extends BinaryExpr {
+final class SubExpr extends BinaryExpr {
   SubExpr() { this.getStaticTarget().getName() = ["-(_:_:)", "&-(_:_:)"] }
 }
 
@@ -70,7 +70,7 @@ class SubExpr extends BinaryExpr {
  * a &* b
  * ```
  */
-class MulExpr extends BinaryExpr {
+final class MulExpr extends BinaryExpr {
   MulExpr() { this.getStaticTarget().getName() = ["*(_:_:)", "&*(_:_:)"] }
 }
 
@@ -80,7 +80,7 @@ class MulExpr extends BinaryExpr {
  * a / b
  * ```
  */
-class DivExpr extends BinaryExpr {
+final class DivExpr extends BinaryExpr {
   DivExpr() { this.getStaticTarget().getName() = "/(_:_:)" }
 }
 
@@ -90,7 +90,7 @@ class DivExpr extends BinaryExpr {
  * a % b
  * ```
  */
-class RemExpr extends BinaryExpr {
+final class RemExpr extends BinaryExpr {
   RemExpr() { this.getStaticTarget().getName() = "%(_:_:)" }
 }
 
@@ -100,7 +100,7 @@ class RemExpr extends BinaryExpr {
  * -a
  * ```
  */
-class UnaryArithmeticOperation extends PrefixUnaryExpr {
+final class UnaryArithmeticOperation extends PrefixUnaryExpr {
   UnaryArithmeticOperation() {
     this instanceof UnaryMinusExpr or
     this instanceof UnaryPlusExpr
@@ -113,7 +113,7 @@ class UnaryArithmeticOperation extends PrefixUnaryExpr {
  * -a
  * ```
  */
-class UnaryMinusExpr extends PrefixUnaryExpr {
+final class UnaryMinusExpr extends PrefixUnaryExpr {
   UnaryMinusExpr() { this.getStaticTarget().getName() = "-(_:)" }
 }
 
@@ -123,6 +123,6 @@ class UnaryMinusExpr extends PrefixUnaryExpr {
  * +a
  * ```
  */
-class UnaryPlusExpr extends PrefixUnaryExpr {
+final class UnaryPlusExpr extends PrefixUnaryExpr {
   UnaryPlusExpr() { this.getStaticTarget().getName() = "+(_:)" }
 }
diff --git a/swift/ql/lib/codeql/swift/elements/expr/BitwiseOperationImpl.qll b/swift/ql/lib/codeql/swift/elements/expr/BitwiseOperation.qll
similarity index 78%
rename from swift/ql/lib/codeql/swift/elements/expr/BitwiseOperationImpl.qll
rename to swift/ql/lib/codeql/swift/elements/expr/BitwiseOperation.qll
index 4e29e6645af22..d50ac5dd088f7 100644
--- a/swift/ql/lib/codeql/swift/elements/expr/BitwiseOperationImpl.qll
+++ b/swift/ql/lib/codeql/swift/elements/expr/BitwiseOperation.qll
@@ -10,7 +10,7 @@ private import codeql.swift.elements.expr.PrefixUnaryExpr
  * ~a
  * ```
  */
-class BitwiseOperation extends Expr {
+final class BitwiseOperation extends Expr {
   BitwiseOperation() {
     this instanceof BinaryBitwiseOperation or
     this instanceof UnaryBitwiseOperation
@@ -33,7 +33,7 @@ class BitwiseOperation extends Expr {
  * a .^ b
  * ```
  */
-class BinaryBitwiseOperation extends BinaryExpr {
+final class BinaryBitwiseOperation extends BinaryExpr {
   BinaryBitwiseOperation() {
     this instanceof AndBitwiseExpr or
     this instanceof OrBitwiseExpr or
@@ -52,7 +52,7 @@ class BinaryBitwiseOperation extends BinaryExpr {
  * a & b
  * ```
  */
-class AndBitwiseExpr extends BinaryExpr {
+final class AndBitwiseExpr extends BinaryExpr {
   AndBitwiseExpr() { this.getStaticTarget().getName() = "&(_:_:)" }
 }
 
@@ -62,7 +62,7 @@ class AndBitwiseExpr extends BinaryExpr {
  * a | b
  * ```
  */
-class OrBitwiseExpr extends BinaryExpr {
+final class OrBitwiseExpr extends BinaryExpr {
   OrBitwiseExpr() { this.getStaticTarget().getName() = "|(_:_:)" }
 }
 
@@ -72,7 +72,7 @@ class OrBitwiseExpr extends BinaryExpr {
  * a ^ b
  * ```
  */
-class XorBitwiseExpr extends BinaryExpr {
+final class XorBitwiseExpr extends BinaryExpr {
   XorBitwiseExpr() { this.getStaticTarget().getName() = "^(_:_:)" }
 }
 
@@ -82,7 +82,7 @@ class XorBitwiseExpr extends BinaryExpr {
  * a .& b
  * ```
  */
-class PointwiseAndExpr extends BinaryExpr {
+final class PointwiseAndExpr extends BinaryExpr {
   PointwiseAndExpr() { this.getOperator().getName() = ".&(_:_:)" }
 }
 
@@ -92,7 +92,7 @@ class PointwiseAndExpr extends BinaryExpr {
  * a .| b
  * ```
  */
-class PointwiseOrExpr extends BinaryExpr {
+final class PointwiseOrExpr extends BinaryExpr {
   PointwiseOrExpr() { this.getOperator().getName() = ".|(_:_:)" }
 }
 
@@ -102,7 +102,7 @@ class PointwiseOrExpr extends BinaryExpr {
  * a .^ b
  * ```
  */
-class PointwiseXorExpr extends BinaryExpr {
+final class PointwiseXorExpr extends BinaryExpr {
   PointwiseXorExpr() { this.getOperator().getName() = ".^(_:_:)" }
 }
 
@@ -113,7 +113,7 @@ class PointwiseXorExpr extends BinaryExpr {
  * a &<<
  * ```
  */
-class ShiftLeftBitwiseExpr extends BinaryExpr {
+final class ShiftLeftBitwiseExpr extends BinaryExpr {
   ShiftLeftBitwiseExpr() { this.getStaticTarget().getName() = ["<<(_:_:)", "&<<(_:_:)"] }
 }
 
@@ -124,7 +124,7 @@ class ShiftLeftBitwiseExpr extends BinaryExpr {
  * a &>>
  * ```
  */
-class ShiftRightBitwiseExpr extends BinaryExpr {
+final class ShiftRightBitwiseExpr extends BinaryExpr {
   ShiftRightBitwiseExpr() { this.getStaticTarget().getName() = [">>(_:_:)", "&>>(_:_:)"] }
 }
 
@@ -134,7 +134,7 @@ class ShiftRightBitwiseExpr extends BinaryExpr {
  * ~a
  * ```
  */
-class UnaryBitwiseOperation extends PrefixUnaryExpr instanceof NotBitwiseExpr { }
+final class UnaryBitwiseOperation extends PrefixUnaryExpr instanceof NotBitwiseExpr { }
 
 /**
  * A bitwise NOT expression.
@@ -142,6 +142,6 @@ class UnaryBitwiseOperation extends PrefixUnaryExpr instanceof NotBitwiseExpr {
  * ~a
  * ```
  */
-class NotBitwiseExpr extends PrefixUnaryExpr {
+final class NotBitwiseExpr extends PrefixUnaryExpr {
   NotBitwiseExpr() { this.getStaticTarget().getName() = "~(_:)" }
 }
diff --git a/swift/ql/lib/codeql/swift/elements/expr/EnumElementExprImpl.qll b/swift/ql/lib/codeql/swift/elements/expr/EnumElementExpr.qll
similarity index 98%
rename from swift/ql/lib/codeql/swift/elements/expr/EnumElementExprImpl.qll
rename to swift/ql/lib/codeql/swift/elements/expr/EnumElementExpr.qll
index 70432ccae456a..3a856af1f9206 100644
--- a/swift/ql/lib/codeql/swift/elements/expr/EnumElementExprImpl.qll
+++ b/swift/ql/lib/codeql/swift/elements/expr/EnumElementExpr.qll
@@ -19,7 +19,7 @@ private import codeql.swift.elements.decl.EnumElementDecl
  *   ...
  * ```
  */
-class EnumElementExpr extends Expr {
+final class EnumElementExpr extends Expr {
   EnumElementDecl decl;
 
   EnumElementExpr() {
diff --git a/swift/ql/lib/codeql/swift/elements/expr/InitializerCallExprImpl.qll b/swift/ql/lib/codeql/swift/elements/expr/InitializerCallExpr.qll
similarity index 66%
rename from swift/ql/lib/codeql/swift/elements/expr/InitializerCallExprImpl.qll
rename to swift/ql/lib/codeql/swift/elements/expr/InitializerCallExpr.qll
index dcb4dff4ba9df..795dc8e0bebbe 100644
--- a/swift/ql/lib/codeql/swift/elements/expr/InitializerCallExprImpl.qll
+++ b/swift/ql/lib/codeql/swift/elements/expr/InitializerCallExpr.qll
@@ -2,8 +2,8 @@ private import codeql.swift.elements.expr.MethodCallExpr
 private import codeql.swift.elements.expr.InitializerLookupExpr
 private import codeql.swift.elements.decl.Initializer
 
-class InitializerCallExpr extends MethodCallExpr {
+final class InitializerCallExpr extends MethodCallExpr {
   InitializerCallExpr() { this.getFunction() instanceof InitializerLookupExpr }
 
-  override Initializer getStaticTarget() { result = super.getStaticTarget() }
+  Initializer getStaticTarget() { result = super.getStaticTarget() }
 }
diff --git a/swift/ql/lib/codeql/swift/elements/expr/InitializerLookupExpr.qll b/swift/ql/lib/codeql/swift/elements/expr/InitializerLookupExpr.qll
new file mode 100644
index 0000000000000..4eade2ff5c756
--- /dev/null
+++ b/swift/ql/lib/codeql/swift/elements/expr/InitializerLookupExpr.qll
@@ -0,0 +1,13 @@
+private import codeql.swift.elements.expr.MethodLookupExpr
+private import codeql.swift.elements.expr.MethodLookupExprImpl::Impl as Impl
+private import codeql.swift.elements.decl.Initializer
+
+final private class InitializerLookupExprImpl extends Impl::MethodLookupExpr {
+  InitializerLookupExprImpl() { super.getMethod() instanceof Initializer }
+
+  override string toString() { result = this.getMember().toString() }
+}
+
+final class InitializerLookupExpr extends MethodLookupExpr, InitializerLookupExprImpl {
+  Initializer getMethod() { result = super.getMethod() }
+}
diff --git a/swift/ql/lib/codeql/swift/elements/expr/InitializerLookupExprImpl.qll b/swift/ql/lib/codeql/swift/elements/expr/InitializerLookupExprImpl.qll
deleted file mode 100644
index 26972894ec68f..0000000000000
--- a/swift/ql/lib/codeql/swift/elements/expr/InitializerLookupExprImpl.qll
+++ /dev/null
@@ -1,10 +0,0 @@
-private import codeql.swift.elements.expr.MethodLookupExpr
-private import codeql.swift.elements.decl.Initializer
-
-class InitializerLookupExpr extends MethodLookupExpr {
-  InitializerLookupExpr() { super.getMethod() instanceof Initializer }
-
-  override Initializer getMethod() { result = super.getMethod() }
-
-  override string toString() { result = this.getMember().toString() }
-}
diff --git a/swift/ql/lib/codeql/swift/elements/expr/LogicalOperationImpl.qll b/swift/ql/lib/codeql/swift/elements/expr/LogicalOperation.qll
similarity index 75%
rename from swift/ql/lib/codeql/swift/elements/expr/LogicalOperationImpl.qll
rename to swift/ql/lib/codeql/swift/elements/expr/LogicalOperation.qll
index 57713551e4317..c261a2a378f90 100644
--- a/swift/ql/lib/codeql/swift/elements/expr/LogicalOperationImpl.qll
+++ b/swift/ql/lib/codeql/swift/elements/expr/LogicalOperation.qll
@@ -10,28 +10,28 @@ private predicate unaryHasName(PrefixUnaryExpr e, string name) {
 
 private predicate binaryHasName(BinaryExpr e, string name) { e.getStaticTarget().getName() = name }
 
-class LogicalAndExpr extends BinaryExpr {
+final class LogicalAndExpr extends BinaryExpr {
   LogicalAndExpr() { binaryHasName(this, "&&(_:_:)") }
 }
 
-class LogicalOrExpr extends BinaryExpr {
+final class LogicalOrExpr extends BinaryExpr {
   LogicalOrExpr() { binaryHasName(this, "||(_:_:)") }
 }
 
-class BinaryLogicalOperation extends BinaryExpr {
+final class BinaryLogicalOperation extends BinaryExpr {
   BinaryLogicalOperation() {
     this instanceof LogicalAndExpr or
     this instanceof LogicalOrExpr
   }
 }
 
-class NotExpr extends PrefixUnaryExpr {
+final class NotExpr extends PrefixUnaryExpr {
   NotExpr() { unaryHasName(this, "!(_:)") }
 }
 
-class UnaryLogicalOperation extends PrefixUnaryExpr instanceof NotExpr { }
+final class UnaryLogicalOperation extends PrefixUnaryExpr instanceof NotExpr { }
 
-class LogicalOperation extends Expr {
+final class LogicalOperation extends Expr {
   LogicalOperation() {
     this instanceof BinaryLogicalOperation or
     this instanceof UnaryLogicalOperation
diff --git a/swift/ql/lib/codeql/swift/elements/expr/MethodCallExprImpl.qll b/swift/ql/lib/codeql/swift/elements/expr/MethodCallExpr.qll
similarity index 79%
rename from swift/ql/lib/codeql/swift/elements/expr/MethodCallExprImpl.qll
rename to swift/ql/lib/codeql/swift/elements/expr/MethodCallExpr.qll
index 65d7dac7576da..9bffe97d12962 100644
--- a/swift/ql/lib/codeql/swift/elements/expr/MethodCallExprImpl.qll
+++ b/swift/ql/lib/codeql/swift/elements/expr/MethodCallExpr.qll
@@ -1,9 +1,10 @@
+private import ApplyExprExt
 private import codeql.swift.elements.expr.CallExpr
 private import codeql.swift.elements.expr.ApplyExpr
 private import codeql.swift.elements.expr.SuperRefExpr
 private import codeql.swift.elements.expr.SelfRefExpr
 
-class MethodCallExpr extends CallExpr, MethodApplyExpr {
+final class MethodCallExpr extends CallExpr, MethodApplyExpr {
   predicate isSelfCall() { this.getQualifier() instanceof SelfRefExpr }
 
   predicate isSuperCall() { this.getQualifier() instanceof SuperRefExpr }
diff --git a/swift/ql/lib/codeql/swift/elements/expr/NilCoalescingExprImpl.qll b/swift/ql/lib/codeql/swift/elements/expr/NilCoalescingExpr.qll
similarity index 85%
rename from swift/ql/lib/codeql/swift/elements/expr/NilCoalescingExprImpl.qll
rename to swift/ql/lib/codeql/swift/elements/expr/NilCoalescingExpr.qll
index 23fe5fc09c51f..e527541d7bace 100644
--- a/swift/ql/lib/codeql/swift/elements/expr/NilCoalescingExprImpl.qll
+++ b/swift/ql/lib/codeql/swift/elements/expr/NilCoalescingExpr.qll
@@ -8,6 +8,6 @@ private import codeql.swift.elements.expr.BinaryExpr
 /**
  * A Swift nil-coalesing expr (`??`).
  */
-class NilCoalescingExpr extends BinaryExpr {
+final class NilCoalescingExpr extends BinaryExpr {
   NilCoalescingExpr() { this.getStaticTarget().getName() = "??(_:_:)" }
 }
diff --git a/swift/ql/lib/codeql/swift/elements/expr/SelfRefExprImpl.qll b/swift/ql/lib/codeql/swift/elements/expr/SelfRefExpr.qll
similarity index 88%
rename from swift/ql/lib/codeql/swift/elements/expr/SelfRefExprImpl.qll
rename to swift/ql/lib/codeql/swift/elements/expr/SelfRefExpr.qll
index 7ffc7a6af2057..e5178f9ccab93 100644
--- a/swift/ql/lib/codeql/swift/elements/expr/SelfRefExprImpl.qll
+++ b/swift/ql/lib/codeql/swift/elements/expr/SelfRefExpr.qll
@@ -3,7 +3,7 @@ private import codeql.swift.elements.decl.Method
 private import codeql.swift.elements.decl.VarDecl
 
 /** A reference to `self`. */
-class SelfRefExpr extends DeclRefExpr {
+final class SelfRefExpr extends DeclRefExpr {
   Method method;
 
   SelfRefExpr() { this.getDecl() = method.getSelfParam() }
diff --git a/swift/ql/lib/codeql/swift/elements/type/NumericTypeImpl.qll b/swift/ql/lib/codeql/swift/elements/type/NumericType.qll
similarity index 80%
rename from swift/ql/lib/codeql/swift/elements/type/NumericTypeImpl.qll
rename to swift/ql/lib/codeql/swift/elements/type/NumericType.qll
index 1becac4493b45..b4c4975d4bd31 100644
--- a/swift/ql/lib/codeql/swift/elements/type/NumericTypeImpl.qll
+++ b/swift/ql/lib/codeql/swift/elements/type/NumericType.qll
@@ -4,7 +4,7 @@ private import swift
  * A floating-point type. This includes the `Float` type, the `Double`, and
  * builtin floating-point types.
  */
-class FloatingPointType extends Type {
+final class FloatingPointType extends Type {
   FloatingPointType() {
     this.getName() = ["Float", "Double"] or
     this instanceof BuiltinFloatType
@@ -12,14 +12,14 @@ class FloatingPointType extends Type {
 }
 
 /** The `Character` type. */
-class CharacterType extends StructType {
+final class CharacterType extends StructType {
   CharacterType() { this.getName() = "Character" }
 }
 
 /**
  * An integer-like type. For example, `Int`, `Int16`, `Uint16`, etc.
  */
-class IntegralType extends Type {
+final class IntegralType extends Type {
   IntegralType() {
     this.getName() =
       ["Int", "Int8", "Int16", "Int32", "Int64", "UInt", "UInt8", "UInt16", "UInt32", "UInt64"]
@@ -29,14 +29,14 @@ class IntegralType extends Type {
 }
 
 /** The `Bool` type. */
-class BoolType extends Type {
+final class BoolType extends Type {
   BoolType() { this.getName() = "Bool" }
 }
 
 /**
  * A numeric type. This includes the integer and floating point types.
  */
-class NumericType extends Type {
+final class NumericType extends Type {
   NumericType() {
     this instanceof IntegralType or
     this instanceof FloatingPointType