1 /*

     2  * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    23 

    24 package shapegen;

    25 

    26 import java.util.ArrayList;

    27 import java.util.HashMap;

    28 import java.util.List;

    29 import java.util.Map;

    30 import java.io.IOException;

    31 import java.io.StringReader;

    32 

    33 import static java.lang.Character.isLetter;

    34 import static java.lang.Character.isUpperCase;

    35 import static java.lang.Character.isWhitespace;

    36 

    37 /**

    38  * Parse a type template definition string

    39  *

    40  *   input     :: classDef

    41  *   classDef  :: letter [ ( classDef* ) ]

    42  *

    43  * @author Robert Field

    44  */

    45 public class TTParser extends StringReader {

    46 

    47     private Map<Character, TTNode> letterMap = new HashMap<>();

    48     private char ch;

    49 

    50     private final String def;

    51 

    52     public TTParser(String s) {

    53         super(s);

    54         this.def = s;

    55     }

    56 

    57     private void advance() throws IOException {

    58         do {

    59             ch = (char)read();

    60         } while (isWhitespace(ch));

    61     }

    62 

    63     public TTNode parse() {

    64         try {

    65             advance();

    66             return classDef();

    67         } catch (IOException t) {

    68             throw new RuntimeException(t);

    69         }

    70     }

    71 

    72     private TTNode classDef() throws IOException {

    73         if (!isLetter(ch)) {

    74             if (ch == (char)-1) {

    75                 throw new IOException("Unexpected end of type template in " + def);

    76             } else {

    77                 throw new IOException("Unexpected character in type template: " + (Character)ch + " in " + def);

    78             }

    79         }

    80         char nodeCh = ch;

    81         TTNode node = letterMap.get(nodeCh);

    82         boolean canBeClass = isUpperCase(nodeCh);

    83         advance();

    84         if (node == null) {

    85             List<TTNode> subtypes = new ArrayList<>();

    86             if (ch == '(') {

    87                 advance();

    88                 while (ch != ')') {

    89                     subtypes.add(classDef());

    90                 }

    91                 advance();

    92             }

    93             node = new TTNode(subtypes, canBeClass);

    94             letterMap.put(nodeCh, node);

    95         }

    96         return node;

    97     }

    98 }