not null computable version of Computable interface

diff --git a/platform/util/src/com/intellij/openapi/util/NotNullComputable.java b/platform/util/src/com/intellij/openapi/util/NotNullComputable.java
new file mode 100644 (file)
index 0000000..79a97a4
--- /dev/null
+++ b/platform/util/src/com/intellij/openapi/util/NotNullComputable.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2000-2011 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.openapi.util;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * @author Nikolay Matveev
+ */
+public interface NotNullComputable<T> extends Computable<T> {
+
+  @NotNull
+  T compute();
+
+  NotNullComputable<Boolean> TRUE = new NotNullComputable<Boolean>() {
+
+    @NotNull
+    @Override
+    public Boolean compute() {
+      return Boolean.TRUE;
+    }
+  };
+}