# HG changeset patch
# User wenzelm
# Date 1677597923 -3600
# Node ID 149cc77f7348b6f4bf5d86926490db45b6aa9ea4
# Parent  cb2c19481fe79061e86500d2e7813ca399860a84
clafified signature: simplify object-oriented reuse;

diff -r cb2c19481fe7 -r 149cc77f7348 src/Pure/Tools/build.scala
--- a/src/Pure/Tools/build.scala	Tue Feb 28 14:20:57 2023 +0100
+++ b/src/Pure/Tools/build.scala	Tue Feb 28 16:25:23 2023 +0100
@@ -44,16 +44,13 @@
 
   /* engine */
 
-  abstract class Engine(val name: String) extends Isabelle_System.Service {
+  class Engine(val name: String) extends Isabelle_System.Service {
     override def toString: String = name
-    def init(build_context: Build_Process.Context): Build_Process
+    def init(build_context: Build_Process.Context): Build_Process =
+      new Build_Process(build_context)
   }
 
-  class Default_Engine extends Engine("") {
-    override def toString: String = "<default>"
-    override def init(build_context: Build_Process.Context): Build_Process =
-      new Build_Process(build_context)
-  }
+  class Default_Engine extends Engine("") { override def toString: String = "<default>" }
 
   lazy val engines: List[Engine] =
     Isabelle_System.make_services(classOf[Engine])