Add regression test

Author: nicolasstucki

tests/neg/scoped-quoted-expr-proto.scala

@@ -0,0 +1,83 @@
+package a {
+
+  trait Expr[+T]
+  trait QCtx
+
+  /*Quote*/ def q[T](x: T)(given QCtx): Expr[T] = ???
+  /*Splice*/ def s[T](x: (given QCtx) => Expr[T]): T = ???
+  /*run*/ def r[T](x: (given QCtx) => Expr[T]): T = ???
+
+
+  val test: Any = {
+
+    def pow(x: Expr[Double], n: Int)(given QCtx): Expr[Double] =
+      if n == 0 then q{1.0} else q{ s{x} * s{pow(x, n - 1)} }
+
+    r {
+      q{ (x: Double) => s{pow(q{x}, 5)} }
+    }
+
+    r {
+      q{ (x: Double) =>
+        s{
+          val y = q{x}
+          pow(q{s{y}}, 5)
+        }
+      }
+    }
+
+    r {
+      var escaped: Expr[Any] = null
+      q{ (x: Double) =>
+        s{
+          escaped = q{x} // 💥
+          pow(q{x}, 5)
+        }
+      }
+    }
+  }
+
+}
+
+
+package b {
+
+  trait QCtx {
+    type Expr[+T]
+  }
+
+  /*Quote*/ def q[T](x: T)(given qctx: QCtx): qctx.Expr[T] = ???
+  /*Splice*/ def s[T](given qctx0: QCtx)(x: (given qctx: QCtx { type Expr[+T] >: qctx0.Expr[T] }) => qctx.Expr[T]): T = ???
+  /*run*/ def r[T](x: (given qctx: QCtx) => qctx.Expr[T]): T = ???
+
+
+  val test: Any = {
+
+    def pow(given qctx: QCtx)(x: qctx.Expr[Double], n: Int): qctx.Expr[Double] =
+      if n == 0 then q{1.0} else q{ s{x} * s{pow(x, n - 1)} }
+
+    r {
+      q{ (x: Double) => s{pow(q{x}, 5)} }
+    }
+
+    r {
+      q{ (x: Double) =>
+        s{
+          val y = q{x}
+          pow(q{s{y}}, 5)
+        }
+      }
+    }
+
+    r { (given qctx) =>
+      var escaped: qctx.Expr[Double] = ???
+      q{ (x: Double) =>
+        s{
+          escaped = q{x} // error
+          pow(q{x}, 5)
+        }
+      }
+    }
+  }
+
+}