-/*******************************************************************************\r
- * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
- * in Industry THTH ry.\r
- * All rights reserved. This program and the accompanying materials\r
- * are made available under the terms of the Eclipse Public License v1.0\r
- * which accompanies this distribution, and is available at\r
- * http://www.eclipse.org/legal/epl-v10.html\r
- *\r
- * Contributors:\r
- * VTT Technical Research Centre of Finland - initial API and implementation\r
- *******************************************************************************/\r
-package org.simantics.utils.datastructures.persistent;\r
-\r
-public abstract class ImmutableStack<T> {\r
- \r
- private ImmutableStack() { \r
- }\r
- \r
- private static class SingleStackNode<T> extends ImmutableStack<T> {\r
- ImmutableStack<T> parent;\r
- T value;\r
- \r
- public SingleStackNode(ImmutableStack<T> parent, T value) { \r
- this.parent = parent;\r
- this.value = value;\r
- }\r
-\r
- @Override\r
- public T get(int i) {\r
- return i==0 ? value : parent.get(i-1);\r
- } \r
- }\r
- \r
- private static class MultiStackNode<T> extends ImmutableStack<T> {\r
- ImmutableStack<T> parent;\r
- T[] values;\r
- \r
- public MultiStackNode(ImmutableStack<T> parent, T[] values) { \r
- this.parent = parent;\r
- this.values = values;\r
- }\r
-\r
- @Override\r
- public T get(int i) {\r
- return i<values.length ? values[i] : parent.get(i-values.length);\r
- } \r
- }\r
- \r
- private static class EmptyStack<T> extends ImmutableStack<T> {\r
-\r
- @Override\r
- public T get(int i) {\r
- throw new IllegalArgumentException("No such element in stack.");\r
- }\r
- \r
- }\r
- \r
- @SuppressWarnings({ "rawtypes" })\r
- static final EmptyStack EMPTY = new EmptyStack();\r
- \r
- public ImmutableStack<T> push(T value) {\r
- return new SingleStackNode<T>(this, value);\r
- }\r
- \r
- public ImmutableStack<T> push(T[] values) {\r
- if(values.length > 1)\r
- return new MultiStackNode<T>(this, values);\r
- else if(values.length == 1)\r
- return new SingleStackNode<T>(this, values[0]);\r
- else\r
- return this;\r
- }\r
- \r
- public abstract T get(int i); \r
- \r
- @SuppressWarnings("unchecked")\r
- public static <T> ImmutableStack<T> empty() {\r
- return (ImmutableStack<T>)EMPTY;\r
- }\r
- \r
- public static <T> ImmutableStack<T> of(T value) {\r
- return new SingleStackNode<T>(null, value);\r
- }\r
- \r
- @SuppressWarnings("unchecked")\r
- public static <T> ImmutableStack<T> of(T[] values) {\r
- if(values.length > 1)\r
- return new MultiStackNode<T>((ImmutableStack<T>)empty(), values);\r
- else if(values.length == 1)\r
- return new SingleStackNode<T>((ImmutableStack<T>)empty(), values[0]);\r
- else\r
- return empty();\r
- }\r
-}\r
+/*******************************************************************************
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management
+ * in Industry THTH ry.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ * VTT Technical Research Centre of Finland - initial API and implementation
+ *******************************************************************************/
+package org.simantics.utils.datastructures.persistent;
+
+public abstract class ImmutableStack<T> {
+
+ private ImmutableStack() {
+ }
+
+ private static class SingleStackNode<T> extends ImmutableStack<T> {
+ ImmutableStack<T> parent;
+ T value;
+
+ public SingleStackNode(ImmutableStack<T> parent, T value) {
+ this.parent = parent;
+ this.value = value;
+ }
+
+ @Override
+ public T get(int i) {
+ return i==0 ? value : parent.get(i-1);
+ }
+ }
+
+ private static class MultiStackNode<T> extends ImmutableStack<T> {
+ ImmutableStack<T> parent;
+ T[] values;
+
+ public MultiStackNode(ImmutableStack<T> parent, T[] values) {
+ this.parent = parent;
+ this.values = values;
+ }
+
+ @Override
+ public T get(int i) {
+ return i<values.length ? values[i] : parent.get(i-values.length);
+ }
+ }
+
+ private static class EmptyStack<T> extends ImmutableStack<T> {
+
+ @Override
+ public T get(int i) {
+ throw new IllegalArgumentException("No such element in stack.");
+ }
+
+ }
+
+ @SuppressWarnings({ "rawtypes" })
+ static final EmptyStack EMPTY = new EmptyStack();
+
+ public ImmutableStack<T> push(T value) {
+ return new SingleStackNode<T>(this, value);
+ }
+
+ public ImmutableStack<T> push(T[] values) {
+ if(values.length > 1)
+ return new MultiStackNode<T>(this, values);
+ else if(values.length == 1)
+ return new SingleStackNode<T>(this, values[0]);
+ else
+ return this;
+ }
+
+ public abstract T get(int i);
+
+ @SuppressWarnings("unchecked")
+ public static <T> ImmutableStack<T> empty() {
+ return (ImmutableStack<T>)EMPTY;
+ }
+
+ public static <T> ImmutableStack<T> of(T value) {
+ return new SingleStackNode<T>(null, value);
+ }
+
+ @SuppressWarnings("unchecked")
+ public static <T> ImmutableStack<T> of(T[] values) {
+ if(values.length > 1)
+ return new MultiStackNode<T>((ImmutableStack<T>)empty(), values);
+ else if(values.length == 1)
+ return new SingleStackNode<T>((ImmutableStack<T>)empty(), values[0]);
+ else
+ return empty();
+ }
+}
Code Review / simantics / platform.git / blobdiff