1 files changed, 103 insertions, 0 deletions
diff --git a/qpid/java/common/src/main/java/org/apache/qpid/messaging/util/Lexicon.java b/qpid/java/common/src/main/java/org/apache/qpid/messaging/util/Lexicon.java
new file mode 100644
index 0000000000..9ab610f37a
--- /dev/null
+++ b/qpid/java/common/src/main/java/org/apache/qpid/messaging/util/Lexicon.java
@@ -0,0 +1,103 @@
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.qpid.messaging.util;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Pattern;
+
+
+/**
+ * Lexicon
+ *
+ */
+
+public class Lexicon
+{
+
+    private List<Token.Type> types;
+    private Token.Type eof;
+
+    public Lexicon()
+    {
+        this.types = new ArrayList<Token.Type>();
+        this.eof = null;
+    }
+
+    public Token.Type define(String name, String pattern)
+    {
+        Token.Type t = new Token.Type(name, pattern);
+        types.add(t);
+        return t;
+    }
+
+    public Token.Type eof(String name)
+    {
+        Token.Type t = new Token.Type(name, null);
+        eof = t;
+        return t;
+    }
+
+    public Lexer compile()
+    {
+        StringBuilder joined = new StringBuilder();
+        for (Token.Type t : types)
+        {
+            if (joined.length() > 0)
+            {
+                joined.append('|');
+            }
+            joined.append('(').append(t.getPattern()).append(')');
+        }
+        Pattern rexp = Pattern.compile(joined.toString());
+        return new Lexer(new ArrayList<Token.Type>(types), eof, rexp);
+    }
+
+    public static final void main(String[] args)
+    {
+        StringBuilder input = new StringBuilder();
+        for (String a : args)
+        {
+            if (input.length() > 0)
+            {
+                input.append(" ");
+            }
+
+            input.append(a);
+        }
+
+        Lexicon lxi = new Lexicon();
+        lxi.define("FOR", "for");
+        lxi.define("IF", "if");
+        lxi.define("LPAREN", "\\(");
+        lxi.define("RPAREN", "\\)");
+        lxi.define("ID", "[\\S]+");
+        lxi.define("WSPACE", "[\\s]+");
+        lxi.eof("EOF");
+        Lexer lx = lxi.compile();
+
+        for (Token t : lx.lex(input.toString()))
+        {
+            System.out.println(t);
+        }
+    }
+
+}