--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/truffle/com.oracle.truffle.api/src/com/oracle/truffle/api/utilities/JSONHelper.java	Wed Jun 17 10:58:08 2015 +0200
@@ -0,0 +1,237 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.truffle.api.utilities;
+
+import java.util.*;
+
+import com.oracle.truffle.api.nodes.*;
+import com.oracle.truffle.api.source.*;
+
+/**
+ * Helper function that allows to dump the AST during creation to a JSON format.
+ */
+public class JSONHelper {
+
+    private static StringBuilder AstJsonDumpBuilder = new StringBuilder();
+
+    public static void dumpNewChild(Node parentNode, Node childNode) {
+        if (AstJsonDumpBuilder != null) {
+            AstJsonDumpBuilder.append("{ \"action\": \"insertNode\", \"parentId\": \"" + getID(parentNode) + "\", \"newId\": \"" + getID(childNode) + "\" },\n");
+        }
+    }
+
+    public static void dumpReplaceChild(Node oldNode, Node newNode, CharSequence reason) {
+        if (AstJsonDumpBuilder != null) {
+            AstJsonDumpBuilder.append("{ \"action\": \"replaceNode\", \"oldId\": \"" + getID(oldNode) + "\", \"newId\": \"" + getID(newNode) + "\", \"reason\": " + quote(reason) + " },\n");
+        }
+    }
+
+    public static void dumpNewNode(Node newNode) {
+        if (AstJsonDumpBuilder != null) {
+            AstJsonDumpBuilder.append("{ \"action\": \"createNode\", \"newId\": \"" + getID(newNode) + "\", \"type\": \"" + getType(newNode) + "\", \"description\": \"" + newNode.getDescription() +
+                            "\", \"language\": \"" + newNode.getLanguage() + "\"" + getSourceSectionInfo(newNode) + " },\n");
+        }
+    }
+
+    private static String getSourceSectionInfo(Node newNode) {
+        SourceSection sourceSection = newNode.getSourceSection();
+        if (sourceSection != null) {
+            return ", \"identifier\": \"" + sourceSection.getIdentifier() + "\" ";
+        } else {
+            return "";
+        }
+    }
+
+    public static String getResult() {
+        return AstJsonDumpBuilder.toString();
+    }
+
+    private static String getID(Node newChild) {
+        return String.valueOf(newChild.hashCode());
+    }
+
+    private static String getType(Node node) {
+        return node.getClass().getSimpleName();
+    }
+
+    private static String quote(CharSequence value) {
+        StringBuilder builder = new StringBuilder(value.length() + 2);
+        builder.append('"');
+        for (int i = 0; i < value.length(); i++) {
+            char c = value.charAt(i);
+            switch (c) {
+                case '"':
+                    builder.append("\\\"");
+                    break;
+                case '\\':
+                    builder.append("\\\\");
+                    break;
+                case '\b':
+                    builder.append("\\b");
+                    break;
+                case '\f':
+                    builder.append("\\f");
+                    break;
+                case '\n':
+                    builder.append("\\n");
+                    break;
+                case '\r':
+                    builder.append("\\r");
+                    break;
+                case '\t':
+                    builder.append("\\t");
+                    break;
+                default: {
+                    if (c < ' ') {
+                        builder.append("\\u00");
+                        builder.append(Character.forDigit((c >> 4) & 0xF, 16));
+                        builder.append(Character.forDigit(c & 0xF, 16));
+                    } else {
+                        builder.append(c);
+                    }
+                }
+            }
+        }
+        builder.append('"');
+        return builder.toString();
+    }
+
+    public static void restart() {
+        AstJsonDumpBuilder = new StringBuilder();
+    }
+
+    public static JSONObjectBuilder object() {
+        return new JSONObjectBuilder();
+    }
+
+    public static JSONArrayBuilder array() {
+        return new JSONArrayBuilder();
+    }
+
+    public abstract static class JSONStringBuilder {
+        @Override
+        public final String toString() {
+            StringBuilder sb = new StringBuilder();
+            appendTo(sb);
+            return sb.toString();
+        }
+
+        protected abstract void appendTo(StringBuilder sb);
+
+        protected static void appendValue(StringBuilder sb, Object value) {
+            if (value instanceof JSONStringBuilder) {
+                ((JSONStringBuilder) value).appendTo(sb);
+            } else if (value instanceof Integer || value instanceof Boolean || value == null) {
+                sb.append(value);
+            } else {
+                sb.append(quote(String.valueOf(value)));
+            }
+        }
+    }
+
+    public static final class JSONObjectBuilder extends JSONStringBuilder {
+        private final Map<String, Object> contents = new LinkedHashMap<>();
+
+        private JSONObjectBuilder() {
+        }
+
+        public JSONObjectBuilder add(String key, String value) {
+            contents.put(key, value);
+            return this;
+        }
+
+        public JSONObjectBuilder add(String key, Number value) {
+            contents.put(key, value);
+            return this;
+        }
+
+        public JSONObjectBuilder add(String key, Boolean value) {
+            contents.put(key, value);
+            return this;
+        }
+
+        public JSONObjectBuilder add(String key, JSONStringBuilder value) {
+            contents.put(key, value);
+            return this;
+        }
+
+        @Override
+        protected void appendTo(StringBuilder sb) {
+            sb.append("{");
+            boolean comma = false;
+            for (Map.Entry<String, Object> entry : contents.entrySet()) {
+                if (comma) {
+                    sb.append(", ");
+                }
+                sb.append(quote(entry.getKey()));
+                sb.append(": ");
+                appendValue(sb, entry.getValue());
+                comma = true;
+            }
+            sb.append("}");
+        }
+    }
+
+    public static final class JSONArrayBuilder extends JSONStringBuilder {
+        private final List<Object> contents = new ArrayList<>();
+
+        private JSONArrayBuilder() {
+        }
+
+        public JSONArrayBuilder add(String value) {
+            contents.add(value);
+            return this;
+        }
+
+        public JSONArrayBuilder add(Number value) {
+            contents.add(value);
+            return this;
+        }
+
+        public JSONArrayBuilder add(Boolean value) {
+            contents.add(value);
+            return this;
+        }
+
+        public JSONArrayBuilder add(JSONStringBuilder value) {
+            contents.add(value);
+            return this;
+        }
+
+        @Override
+        protected void appendTo(StringBuilder sb) {
+            sb.append("[");
+            boolean comma = false;
+            for (Object value : contents) {
+                if (comma) {
+                    sb.append(", ");
+                }
+                appendValue(sb, value);
+                comma = true;
+            }
+            sb.append("]");
+        }
+    }
+}