[GR-29785] JavaClass should print better string then <foreign object at xxxxx>

PullRequest: graalpython/1668

Author: ppisl

graalpython/com.oracle.graal.python.test/src/tests/test_interop.py

@@ -638,3 +638,17 @@ def test_foreign_slice_setting():
             assert True
         else:
             assert False, "should throw a type error again"
+            
+    def test_foreign_repl():
+        from java.util.logging import LogRecord
+        from java.util.logging import Level
+        
+        lr = LogRecord(Level.ALL, "message")
+        assert repr(LogRecord).startswith('<JavaClass[java.util.logging.LogRecord] at')
+        assert repr(lr).startswith('<JavaObject[java.util.logging.LogRecord] at')
+        
+        from java.lang import Integer
+        i = Integer('22')
+        assert repr(Integer).startswith('<JavaClass[java.lang.Integer] at')
+        assert repr(i) == '22'
+        

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/foreign/ForeignObjectBuiltins.java

@@ -82,6 +82,7 @@
 import com.oracle.graal.python.builtins.PythonBuiltins;
 import com.oracle.graal.python.builtins.objects.PNone;
 import com.oracle.graal.python.builtins.objects.PNotImplemented;
+import com.oracle.graal.python.builtins.objects.PythonAbstractObject;
 import com.oracle.graal.python.builtins.objects.function.PKeyword;
 import com.oracle.graal.python.builtins.objects.ints.PInt;
 import com.oracle.graal.python.builtins.objects.iterator.PForeignArrayIterator;
@@ -876,6 +877,35 @@ protected Object doArray(VirtualFrame frame, Object object,
             return doIt(frame, object);
         }
 
+        @Specialization(guards = "getContext().getEnv().isHostObject(self)")
+        Object doHostObject(VirtualFrame frame, Object self,
+                        @CachedLibrary(limit = "3") InteropLibrary lib) {
+            try {
+                boolean isMetaObject = lib.isMetaObject(self);
+                Object metaObject = isMetaObject
+                                ? self
+                                : lib.hasMetaObject(self) ? lib.getMetaObject(self) : null;
+                if (metaObject != null) {
+                    Object displayName = lib.toDisplayString(metaObject);
+                    String text = createDisplayName(isMetaObject, displayName);
+                    return PythonUtils.format("<%s at 0x%x>", text, PythonAbstractObject.systemHashCode(self));
+                }
+
+            } catch (UnsupportedMessageException ex) {
+                // do nothing
+            }
+            return doIt(frame, self);
+        }
+
+        @CompilerDirectives.TruffleBoundary
+        private static String createDisplayName(boolean isMetaObject, Object object) {
+            StringBuilder sb = new StringBuilder();
+            sb.append(isMetaObject ? "JavaClass[" : "JavaObject[");
+            sb.append(object.toString());
+            sb.append("]");
+            return sb.toString();
+        }
+
         @Fallback
         protected Object doIt(VirtualFrame frame, Object object) {
             return getObjectStrNode().call(frame, object);