Create message for missing arguments

Author: odersky

compiler/src/dotty/tools/dotc/reporting/ErrorMessageID.scala

@@ -67,7 +67,7 @@ enum ErrorMessageID(val isActive: Boolean = true) extends java.lang.Enum[ErrorMe
   case AmbiguousOverloadID // errorNumber: 51
   case ReassignmentToValID // errorNumber: 52
   case TypeDoesNotTakeParametersID // errorNumber: 53
-  case ParameterizedTypeLacksArgumentsID // errorNumber: 54
+  case ParameterizedTypeLacksArgumentsID_UNUSED // errorNumber: 54
   case VarValParametersMayNotBeCallByNameID // errorNumber: 55
   case MissingTypeParameterForID // errorNumber: 56
   case DoesNotConformToBoundID // errorNumber: 57
@@ -184,7 +184,8 @@ enum ErrorMessageID(val isActive: Boolean = true) extends java.lang.Enum[ErrorMe
   case ImplicitSearchTooLargeID // errorNumber: 168
   case TargetNameOnTopLevelClassID // errorNumber: 169
   case NotClassTypeID // errorNumber 170
-  
+  case MissingArgumentID // errorNumer 171
+
   def errorNumber = ordinal - 1
 
 object ErrorMessageID:

compiler/src/dotty/tools/dotc/reporting/messages.scala

@@ -1406,15 +1406,6 @@ import cc.CaptureSet.IdentityCaptRefMap
          |"""
   }
 
-  class ParameterizedTypeLacksArguments(psym: Symbol)(using Context)
-    extends TypeMsg(ParameterizedTypeLacksArgumentsID) {
-    def msg = em"Parameterized $psym lacks argument list"
-    def explain =
-      em"""The $psym is declared with non-implicit parameters, you may not leave
-          |out the parameter list when extending it.
-          |"""
-  }
-
   class VarValParametersMayNotBeCallByName(name: TermName, mutable: Boolean)(using Context)
     extends SyntaxMsg(VarValParametersMayNotBeCallByNameID) {
     def varOrVal = if (mutable) em"${hl("var")}" else em"${hl("val")}"
@@ -1445,6 +1436,13 @@ import cc.CaptureSet.IdentityCaptRefMap
     def explain = em"A fully applied type is expected but $tpe takes $numParams $parameters"
   }
 
+  class MissingArgument(pname: Name, methString: String)(using Context)
+    extends TypeMsg(MissingArgumentID):
+    def msg =
+      if pname.firstPart contains '$' then s"not enough arguments for $methString"
+      else s"missing argument for parameter $pname of $methString"
+    def explain = ""
+
   class DoesNotConformToBound(tpe: Type, which: String, bound: Type)(using Context)
     extends TypeMismatchMsg(
       if which == "lower" then bound else tpe,
@@ -2535,3 +2533,4 @@ import cc.CaptureSet.IdentityCaptRefMap
   extends TypeMsg(NotClassTypeID), ShowMatchTrace(tp):
     def msg = ex"$tp is not a class type"
     def explain = ""
+

compiler/src/dotty/tools/dotc/typer/Applications.scala

@@ -561,12 +561,8 @@ trait Applications extends Compatibility {
             else
               formals1
 
-          def missingArg(n: Int): Unit = {
-            val pname = methodType.paramNames(n)
-            fail(
-              if (pname.firstPart contains '$') s"not enough arguments for $methString"
-              else s"missing argument for parameter $pname of $methString")
-          }
+          def missingArg(n: Int): Unit =
+            fail(MissingArgument(methodType.paramNames(n), methString))
 
           def tryDefault(n: Int, args1: List[Arg]): Unit = {
             val sym = methRef.symbol

tests/neg/i16130.check

@@ -0,0 +1,4 @@
+-- [E171] Type Error: tests/neg/i16130.scala:3:16 ----------------------------------------------------------------------
+3 |  val foo = new Foo {}  // error
+  |                ^^^
+  |                missing argument for parameter x of constructor Foo in trait Foo: (x: Int): Foo

tests/neg/i16130.scala

@@ -0,0 +1,3 @@
+@main def ParameterizedTypeLacksArgumentsID =
+  trait Foo(x: Int)
+  val foo = new Foo {}  // error

tests/neg/i6778.check

@@ -4,7 +4,7 @@
   |                           class A is not a trait
   |
   | longer explanation available when compiling with `-explain`
--- Error: tests/neg/i6778.scala:3:6 ------------------------------------------------------------------------------------
+-- [E171] Type Error: tests/neg/i6778.scala:3:6 ------------------------------------------------------------------------
 3 |class Bar extends Foo with A(10) // error // error
   |      ^
   |      missing argument for parameter x of constructor A in class A: (x: Int): A

tests/neg/i9436.check

@@ -4,7 +4,7 @@
   |          method f1 must be called with () argument
   |
   | longer explanation available when compiling with `-explain`
--- Error: tests/neg/i9436.scala:9:14 -----------------------------------------------------------------------------------
+-- [E171] Type Error: tests/neg/i9436.scala:9:14 -----------------------------------------------------------------------
 9 |  println(x.f2(1)) // error
   |          ^^^^^^^
   |          missing argument for parameter y of method f2: (x: Int, y: Int): Int