#110

build.gradle.kts

@@ -12,7 +12,7 @@ buildscript {
     }
 
     dependencies {
-        classpath("ch.epfl.scala:gradle-bloop_2.12:1.6.1") // suffix is always 2.12, weird
+        classpath("ch.epfl.scala:gradle-bloop_2.12:1.6.2") // suffix is always 2.12, weird
     }
 }
 
@@ -33,7 +33,7 @@ plugins {
     `maven-publish`
     id("io.github.gradle-nexus.publish-plugin") version "1.3.0"
 
-    id("com.github.ben-manes.versions") version "0.49.0"
+    id("com.github.ben-manes.versions") version "0.50.0"
 
     id("io.github.cosmicsilence.scalafix") version "0.1.14"
 }
@@ -144,7 +144,7 @@ allprojects {
 
         val scalaTestV = "3.2.11"
         testFixturesApi("org.scalatest:scalatest_${vs.scalaBinaryV}:${scalaTestV}")
-        testImplementation("org.junit.jupiter:junit-jupiter:5.10.0")
+        testImplementation("org.junit.jupiter:junit-jupiter:5.10.1")
 
         testRuntimeOnly("co.helmethair:scalatest-junit-runner:0.2.0")
     }
@@ -358,6 +358,7 @@ idea {
             ".gradle",
             "gradle",
             "spike",
+            ".history"
         )
     }
 }

core/src/main/scala-2.13.7+/latest/splain/SplainFormattingExtension.scala

@@ -395,9 +395,17 @@ trait SplainFormattingExtension extends typechecker.splain.SplainFormatting with
 
     if (isAux(tpe)) tpe
     else {
-
-      val result = tpe.dealias
-      result
+      val result = tpe.dealias.normalize
+      result match {
+        case p: PolyType =>
+          val target = dealias(p.resultType)
+          val _p = p.copy(
+            resultType = target
+          )
+          _p
+        case _ =>
+          result
+      }
     }
   }
 
@@ -608,11 +616,11 @@ trait SplainFormattingExtension extends typechecker.splain.SplainFormatting with
 
   protected def formatDiffImplNoDisambiguation(found: Type, req: Type, top: Boolean): Formatted = {
 
-    val (left, right) = dealias(found) -> dealias(req)
+    val reduced = Seq(found, req).map(dealias)
+    val Seq(left, right) = reduced
 
-    val normalized = Seq(left, right).map(_.normalize).distinct
-    if (normalized.size == 1) {
-      val only = normalized.head
+    if (reduced.distinct.size == 1) {
+      val only = reduced.head
       val result = formatType(only, top)
 
       val basedOn = Seq(found, req).distinct

core/src/main/scala-2.13.7+/latest/splain/TyperCompatViews.scala

@@ -9,11 +9,9 @@ trait TyperCompatViews {
 
   case class TypeView(self: Type) {
 
-    lazy val extractArgs: List[global.Type] = self match {
-      // PolyType handling is removed for being unsound
-      case t: AliasTypeRef if !isAux(self) =>
-        t.betaReduce.typeArgs.map(a => if (a.typeSymbolDirect.isTypeParameter) WildcardType else a)
-      case _ => self.typeArgs
+    lazy val extractArgs: List[global.Type] = {
+
+      self.typeArgs
     }
 
     lazy val noArgType: Type = if (extractArgs.nonEmpty) {

core/src/test/resources/splain/builtin/BasicSpec/__direct/check

@@ -143,14 +143,7 @@ f invalid because
   implicitly[String]
             ^
 newSource1.scala:11: error: implicit error;
-!I e:
-  DeepHole.C1[
-    DeepHole.T3[
-      DeepHole.T1[List[String], ?],
-      DeepHole.T2[DeepHole.Id, DeepHole.C4, ?],
-      ?
-    ]
-  ]
+!I e: DeepHole.C1[[Z]DeepHole.C2[DeepHole.T1,DeepHole.T2,Z]]
   implicitly[C1[T3]]
             ^
 newSource1.scala:9: error: implicit error;

core/src/test/resources/splain/plugin/VTypeDetailReductionSpec/__direct/check

@@ -10,7 +10,7 @@ val x: vecInt.Head = ??? : Option[String]
                          ^
 newSource1.scala:8: error: implicit error;
 !I e:
-  Option[Int] (reduced from) { FoundReqVsImplicit.vecInt.Head[Int] } =:=
+  Option[Int] (reduced from) { FoundReqVsImplicit.vecInt.Head } =:=
   Option[String]
   Cannot prove that FoundReqVsImplicit.vecInt.Head =:= Option[String].
 
@@ -19,6 +19,6 @@ implicitly[vecInt.Head =:= Option[String]]
 newSource1.scala:10: error: type mismatch;
   Option[String|Int]
   ――(right side reduced from)
-    FoundReqVsImplicit.vecInt.Head[Int]
+    FoundReqVsImplicit.vecInt.Head
 val x: vecInt.Head = ??? : Option[String]
                          ^

core/src/test/resources/splain/plugin/VTypeDetailSpec/__direct/check

@@ -76,3 +76,21 @@ newSource1.scala:16: error: implicit error;
   ――(defined at newSource1.scala:8:13)
       wrongf(new A)
             ^
+newSource1.scala:5: error: implicit error;
+!I e: String :: Int :: Boolean
+      implicitly[K]
+                ^
+newSource1.scala:7: error: type mismatch;
+  String("abc")|String :: Int :: Boolean
+      def v: K = "abc"
+                 ^
+newSource1.scala:5: error: implicit error;
+!I e: String :: Int :: Boolean (reduced from) { Test.K }
+      implicitly[K]
+                ^
+newSource1.scala:7: error: type mismatch;
+  String("abc")|String :: Int :: Boolean
+  ――(right side reduced from)
+    Test.K
+      def v: K = "abc"
+                 ^

core/src/test/scala/splain/plugin/VTypeDetailSpec.scala

@@ -25,6 +25,18 @@ class VTypeDetailSpec extends SpecBase.Direct {
     }
     """
 
+  final val reduceToInfix =
+    """
+    object Test {
+      trait ::[A, B]
+
+      type K = String :: Int :: Boolean
+      implicitly[K]
+
+      def v: K = "abc"
+    }
+    """
+
   describe("#113") {
 
     check(wrongContexts, profile = "-P:splain:Vtype-detail:1", numberOfErrors = 2)
@@ -40,4 +52,11 @@ class VTypeDetailSpec extends SpecBase.Direct {
     check(wrongContexts, profile = "-P:splain:Vtype-detail:6", numberOfErrors = 2)
   }
 
+  describe("#119") {
+
+    check(reduceToInfix, profile = "-P:splain:Vtype-detail:3", numberOfErrors = 2)
+
+    check(reduceToInfix, profile = "-P:splain:Vtype-detail:4", numberOfErrors = 2)
+  }
+
 }

testing/acceptance/src/test/resources/splain/builtin/BasicSpec/__direct/check

@@ -172,15 +172,7 @@ f invalid because
 newSource1.scala:11: error: implicit error;
 !I e:
   splain.acceptance.builtin.StaticBasicSpec.DeepHole.C1[
-    splain.acceptance.builtin.StaticBasicSpec.DeepHole.T3[
-      splain.acceptance.builtin.StaticBasicSpec.DeepHole.T1[List[String], ?],
-      splain.acceptance.builtin.StaticBasicSpec.DeepHole.T2[
-        splain.acceptance.builtin.StaticBasicSpec.DeepHole.Id,
-        splain.acceptance.builtin.StaticBasicSpec.DeepHole.C4,
-        ?
-      ],
-      ?
-    ]
+    [Z]splain.acceptance.builtin.StaticBasicSpec.DeepHole.C2[splain.acceptance.builtin.StaticBasicSpec.DeepHole.T1,splain.acceptance.builtin.StaticBasicSpec.DeepHole.T2,Z]
   ]
   implicitly[C1[T3]]
             ^