--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.ruby.runtime/src/com/oracle/truffle/ruby/runtime/core/RubyHash.java	Mon Jan 06 17:12:09 2014 +0000
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2013 Oracle and/or its affiliates. All rights reserved. This
+ * code is released under a tri EPL/GPL/LGPL license. You can use it,
+ * redistribute it and/or modify it under the terms of the:
+ *
+ * Eclipse Public License version 1.0
+ * GNU General Public License version 2
+ * GNU Lesser General Public License version 2.1
+ */
+package com.oracle.truffle.ruby.runtime.core;
+
+import java.util.*;
+
+import com.oracle.truffle.api.CompilerDirectives.CompilationFinal;
+import com.oracle.truffle.ruby.runtime.objects.*;
+
+/**
+ * Represents the Ruby {@code Hash} class.
+ */
+public class RubyHash extends RubyObject {
+
+    /**
+     * The class from which we create the object that is {@code Hash}. A subclass of
+     * {@link RubyClass} so that we can override {@link #newInstance} and allocate a
+     * {@link RubyHash} rather than a normal {@link RubyBasicObject}.
+     */
+    public static class RubyHashClass extends RubyClass {
+
+        public RubyHashClass(RubyClass objectClass) {
+            super(null, objectClass, "Hash");
+        }
+
+        @Override
+        public RubyBasicObject newInstance() {
+            return new RubyHash(this);
+        }
+
+    }
+
+    public final Map<Object, Object> storage = new LinkedHashMap<>();
+    @CompilationFinal public RubyProc defaultBlock = null;
+
+    public RubyHash(RubyClass rubyClass, RubyProc defaultBlock) {
+        super(rubyClass);
+        initialize(defaultBlock);
+    }
+
+    public RubyHash(RubyClass rubyClass) {
+        super(rubyClass);
+    }
+
+    public void initialize(RubyProc setDefaultBlock) {
+        defaultBlock = setDefaultBlock;
+    }
+
+    @Override
+    public Object dup() {
+        final RubyHash newHash = new RubyHash(rubyClass);
+        newHash.setInstanceVariables(getInstanceVariables());
+        newHash.storage.putAll(storage);
+        return newHash;
+    }
+
+    public void put(Object key, Object value) {
+        checkFrozen();
+
+        storage.put(key, value);
+    }
+
+    public Object get(Object key) {
+        return storage.get(key);
+    }
+
+    public Map<Object, Object> getMap() {
+        return storage;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("{");
+
+        for (Map.Entry<Object, Object> entry : storage.entrySet()) {
+            if (builder.length() > 1) {
+                builder.append(", ");
+            }
+
+            builder.append(entry.getKey().toString());
+            builder.append("=>");
+            builder.append(entry.getValue().toString());
+        }
+
+        builder.append("}");
+        return builder.toString();
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result + ((storage == null) ? 0 : storage.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null) {
+            return false;
+        }
+        if (!(obj instanceof RubyHash)) {
+            return false;
+        }
+        RubyHash other = (RubyHash) obj;
+        if (storage == null) {
+            if (other.storage != null) {
+                return false;
+            }
+        } else if (!storage.equals(other.storage)) {
+            return false;
+        }
+        return true;
+    }
+
+}