From f73d8b6f5e96a1707ab703a7a4b1f82ef263f13a Mon Sep 17 00:00:00 2001
From: Kacper Korban <kacper.f.korban@gmail.com>
Date: Wed, 3 May 2023 04:40:45 +0200
Subject: [PATCH] Move the second type argument to the modify/modifyAll method
 in Scala 3

This allows manually specifying type arguments of the focused field

Also suppress some warnings in Scala 3 macros

related to softwaremill#157
---
 .../quicklens/QuicklensMacros.scala           |  6 ++--
 .../com/softwaremill/quicklens/package.scala  |  6 ++--
 .../quicklens/test/LiteralTypeTest.scala      | 34 +++++++++++++++++++
 3 files changed, 41 insertions(+), 5 deletions(-)
 create mode 100644 quicklens/src/test/scala-3/com/softwaremill/quicklens/test/LiteralTypeTest.scala

diff --git a/quicklens/src/main/scala-3/com/softwaremill/quicklens/QuicklensMacros.scala b/quicklens/src/main/scala-3/com/softwaremill/quicklens/QuicklensMacros.scala
index 00aa09a..7fbd08c 100644
--- a/quicklens/src/main/scala-3/com/softwaremill/quicklens/QuicklensMacros.scala
+++ b/quicklens/src/main/scala-3/com/softwaremill/quicklens/QuicklensMacros.scala
@@ -67,7 +67,7 @@ object QuicklensMacros {
       case Empty
       case Node(children: Seq[(PathSymbol, Seq[PathTree])])
 
-      def <>(symbols: Seq[PathSymbol]): PathTree = (this, symbols) match
+      def <>(symbols: Seq[PathSymbol]): PathTree = ((this, symbols): @unchecked) match
         case (PathTree.Empty, _) =>
           symbols.toPathTree
         case (PathTree.Node(children), (symbol :: Nil)) =>
@@ -283,7 +283,9 @@ object QuicklensMacros {
       )
       val defdefStatements = DefDef(
         defdefSymbol,
-        { case List(List(x)) => Some(mapToCopy(defdefSymbol, mod, x.asExpr.asTerm, tree)) }
+        ((_: @unchecked) match
+          case List(List(x)) => Some(mapToCopy(defdefSymbol, mod, x.asExpr.asTerm, tree))
+        )
       )
       val closure = Closure(Ref(defdefSymbol), None)
       val block = Block(List(defdefStatements), closure)
diff --git a/quicklens/src/main/scala-3/com/softwaremill/quicklens/package.scala b/quicklens/src/main/scala-3/com/softwaremill/quicklens/package.scala
index 12e3e9d..54d5b20 100644
--- a/quicklens/src/main/scala-3/com/softwaremill/quicklens/package.scala
+++ b/quicklens/src/main/scala-3/com/softwaremill/quicklens/package.scala
@@ -9,7 +9,7 @@ package object quicklens {
 
   // #114: obj shouldn't be inline since we want to reference the parameter by-name, rather then embedding the whole
   // expression whenever obj is used; this is especially important for chained .modify invocations
-  extension [S, A](obj: S)
+  extension [S](obj: S)
     /** Create an object allowing modifying the given (deeply nested) field accessible in a `case class` hierarchy via
       * `path` on the given `obj`.
       *
@@ -17,7 +17,7 @@ package object quicklens {
       *
       * You can use `.each` to traverse options, lists, etc.
       */
-    inline def modify(inline path: S => A): PathModify[S, A] = ${ toPathModifyFromFocus('obj, 'path) }
+    inline def modify[A](inline path: S => A): PathModify[S, A] = ${ toPathModifyFromFocus('obj, 'path) }
 
     /** Create an object allowing modifying the given (deeply nested) fields accessible in a `case class` hierarchy via
       * `paths` on the given `obj`.
@@ -26,7 +26,7 @@ package object quicklens {
       *
       * You can use `.each` to traverse options, lists, etc.
       */
-    inline def modifyAll(inline path: S => A, inline paths: (S => A)*): PathModify[S, A] = ${
+    inline def modifyAll[A](inline path: S => A, inline paths: (S => A)*): PathModify[S, A] = ${
       modifyAllImpl('obj, 'path, 'paths)
     }
 
diff --git a/quicklens/src/test/scala-3/com/softwaremill/quicklens/test/LiteralTypeTest.scala b/quicklens/src/test/scala-3/com/softwaremill/quicklens/test/LiteralTypeTest.scala
new file mode 100644
index 0000000..8e8cab3
--- /dev/null
+++ b/quicklens/src/test/scala-3/com/softwaremill/quicklens/test/LiteralTypeTest.scala
@@ -0,0 +1,34 @@
+package com.softwaremill.quicklens.test
+
+import com.softwaremill.quicklens.TestData.duplicate
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
+
+import com.softwaremill.quicklens._
+
+object LiteralTypeTestData {
+  case class Test(f: "foo")
+  case class Test1[A](f: A)
+}
+
+class LiteralTypeTest extends AnyFlatSpec with Matchers {
+  import LiteralTypeTestData._
+
+  it should "modify a literal type field with an explicit parameter" in {
+    Test("foo").modify["foo"](_.f).setTo("foo") should be(Test("foo"))
+  }
+
+  it should "modify a literal type field as a type parameter with an explicit parameter" in {
+    Test1["foo"]("foo").modify["foo"](_.f).setTo("foo") should be(Test1("foo"))
+  }
+
+  it should "not compile for a wrong literal type" in {
+    assertDoesNotCompile("""
+      import com.softwaremill.quicklens.*
+      
+      case class Test1[A](f: A)
+      
+      Test1["foo"]("foo").modify["foo"](_.f).setTo("bar")
+    """)
+  }
+}
\ No newline at end of file