Refactor QuoteMatcher with regard to type params matching, and refine test cases

Author: zeptometer

compiler/src/scala/quoted/runtime/impl/QuoteMatcher.scala

@@ -431,20 +431,6 @@ class QuoteMatcher(debug: Boolean) {
                 case TypeTreeTypeTest(pattern) if isSubTypeUnderEnv(scrutinee, pattern) => matched
                 case _ => notMatched
 
-            // TODO-18271: We might want to restrict type bounds/type defs to match
-            // only when they are empty bounds (<: Nothing :> Any)
-            // to keep behavioral difference minimal
-            case TypeBoundsTree(sclo, schi, scalias) =>
-              pattern match
-                case TypeBoundsTree(ptlo, pthi, ptalias) =>
-                  sclo =?= ptlo &&& schi =?= pthi &&& scalias =?= ptalias
-                case _ => notMatched
-
-            case TypeDef(_, rhs1) =>
-              pattern match
-                case TypeDef(_, rhs2) => rhs1 =?= rhs2
-                case _ => notMatched
-
             /* Match val */
             case scrutinee @ ValDef(_, tpt1, _) =>
               pattern match
@@ -468,6 +454,20 @@ class QuoteMatcher(debug: Boolean) {
                           notMatched
                       case _ => matched
 
+                  /**
+                    * Implementation restriction: The current implementation matches type parameters
+                    * only when they have empty bounds (>: Nothing <: Any)
+                    */
+                  def matchTypeDef(sctypedef: TypeDef, pttypedef: TypeDef): MatchingExprs = sctypedef match
+                    case TypeDef(_, TypeBoundsTree(sclo, schi, EmptyTree))
+                      if sclo.tpe == defn.NothingType && schi.tpe == defn.AnyType =>
+                      pttypedef match
+                        case TypeDef(_, TypeBoundsTree(ptlo, pthi, EmptyTree))
+                          if sclo.tpe == defn.NothingType && schi.tpe == defn.AnyType =>
+                          matched
+                        case _ => notMatched
+                    case _ => notMatched
+
                   def matchParamss(scparamss: List[ParamClause], ptparamss: List[ParamClause])(using Env): optional[(Env, MatchingExprs)] =
                     (scparamss, ptparamss) match {
                       case (ValDefs(scparams) :: screst, ValDefs(ptparams) :: ptrest) =>
@@ -480,7 +480,7 @@ class QuoteMatcher(debug: Boolean) {
                         val (resEnv, mrrest) = withEnv(newEnv)(matchParamss(screst, ptrest))
                         (resEnv, mr1 &&& mrrest)
                       case (TypeDefs(scparams) :: screst, TypeDefs(ptparams) :: ptrest) =>
-                        val mr1 = matchLists(scparams, ptparams)(_ =?= _)
+                        val mr1 = matchLists(scparams, ptparams)(matchTypeDef)
                         val Env(termEnv, typeEnv) = summon[Env]
                         val newEnv = new Env(
                           termEnv = termEnv,

compiler/test/dotty/tools/dotc/CompilationTests.scala

@@ -215,6 +215,7 @@ class CompilationTests {
       compileFilesInDir("tests/run-custom-args/erased", defaultOptions.and("-language:experimental.erasedDefinitions")),
       compileFilesInDir("tests/run-custom-args/fatal-warnings", defaultOptions.and("-Xfatal-warnings")),
       compileFilesInDir("tests/run-custom-args/captures", allowDeepSubtypes.and("-language:experimental.captureChecking")),
+      compileFilesInDir("tests/run-custom-args/quoted-pattern-poly", defaultOptions.and("-language:experimental.quotedPatternsWithPolymorphicFunctions")),
       compileFilesInDir("tests/run-deep-subtype", allowDeepSubtypes),
       compileFilesInDir("tests/run", defaultOptions.and("-Ysafe-init")),
       // Run tests for legacy lazy vals.

tests/run-custom-args/quoted-pattern-poly/quote-match-poly-function-regression.check

@@ -0,0 +1,3 @@
+Case 1 matched
+not matched
+not matched

tests/run-custom-args/quoted-pattern-poly/quote-match-poly-function-regression/Macro_1.scala

@@ -0,0 +1,8 @@
+import scala.quoted.*
+
+inline def testExpr(inline body: Any) = ${ testExprImpl1('body) }
+def testExprImpl1(body: Expr[Any])(using Quotes): Expr[String] =
+  body match
+    case '{ [A] => (x : A, y : A) => (x, y) } => Expr("Case 1 matched")
+    case '{ [A <: Iterable[Int]] => (x : A) => x } => Expr("Case 2 matched")
+    case _ => Expr("not matched")

tests/run-custom-args/quoted-pattern-poly/quote-match-poly-function-regression/Test_2.scala

@@ -0,0 +1,4 @@
+@main def Test: Unit =
+    println(testExpr([B] => (x : B, y : B) => (x, y)))
+    println(testExpr([B <: Iterable[Int]] => (x : B) => x))
+    println(testExpr([B <: List[Int]] => (x : B) => x))

tests/run-macros/quote-match-poly-function.check renamed to tests/run-custom-args/quoted-pattern-poly/quote-match-poly-function.check

@@ -0,0 +1,3 @@
+Case 1 matched
+not matched
+not matched

tests/run-macros/quote-match-poly-function/Macro_1.scala renamed to tests/run-custom-args/quoted-pattern-poly/quote-match-poly-function/Macro_1.scala

@@ -0,0 +1,8 @@
+import scala.quoted.*
+
+inline def testExpr(inline body: Any) = ${ testExprImpl1('body) }
+def testExprImpl1(body: Expr[Any])(using Quotes): Expr[String] =
+  body match
+    case '{ [A] => (x : A, y : A) => (x, y) } => Expr("Case 1 matched")
+    case '{ [A <: Iterable[Int]] => (x : A) => x } => Expr("Case 2 matched")
+    case _ => Expr("not matched")

tests/run-macros/quote-match-poly-function/Test_2.scala renamed to tests/run-custom-args/quoted-pattern-poly/quote-match-poly-function/Test_2.scala

@@ -0,0 +1,4 @@
+@main def Test: Unit =
+    println(testExpr([B] => (x : B, y : B) => (x, y)))
+    println(testExpr([B <: Iterable[Int]] => (x : B) => x))
+    println(testExpr([B <: List[Int]] => (x : B) => x))