libdeng2: Ported cfparser.py from Snowberry (Info file parser)

The Snowberry cfparser.py is the parser that Snowberry uses for all its
configuration, profile, and add-on metadata Info files. Having this in libdeng2
will enable us to read these files natively in Doomsday.

Todo for later: Add tests for the parser.
Todo for later: Take advantage of the scriptsys parsing classes where applicable.

doomsday/libdeng2/data.pri

@@ -8,6 +8,7 @@ HEADERS += \
     include/de/Guard \
     include/de/IBlock \
     include/de/IByteArray \
+    include/de/Info \
     include/de/IReadable \
     include/de/ISerializable \
     include/de/IWritable \
@@ -26,6 +27,7 @@ HEADERS += \
     include/de/data/huffman.h \
     include/de/data/iblock.h \
     include/de/data/ibytearray.h \
+    include/de/data/info.h \
     include/de/data/ireadable.h \
     include/de/data/iserializable.h \
     include/de/data/iwritable.h \
@@ -42,10 +44,11 @@ SOURCES += \
     src/data/bytesubarray.cpp \
     src/data/date.cpp \
     src/data/fixedbytearray.cpp \
-    src/data/huffman.cpp \
     src/data/guard.cpp \
+    src/data/huffman.cpp \
+    src/data/info.cpp \
     src/data/lockable.cpp \
-    src/data/string.cpp \
     src/data/reader.cpp \
+    src/data/string.cpp \
     src/data/time.cpp \
     src/data/writer.cpp

doomsday/libdeng2/include/de/Info

@@ -0,0 +1 @@
+#include "data/info.h"

doomsday/libdeng2/include/de/data/info.h

@@ -0,0 +1,194 @@
+/*
+ * The Doomsday Engine Project -- libdeng2
+ *
+ * Copyright (c) 2012 Jaakko Keränen <jaakko.keranen@iki.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef LIBDENG2_INFO_H
+#define LIBDENG2_INFO_H
+
+#include "../String"
+#include <QStringList>
+#include <QHash>
+
+namespace de {
+
+/**
+ * Key/value tree. Read from the "Snowberry" Info file format.
+ *
+ * This implementation has been ported to C++ based on cfparser.py from
+ * Snowberry.
+ *
+ * @todo Document Info syntax in wiki, with example.
+ */
+class Info
+{
+public:
+    /**
+     * Base class for all elements.
+     */
+    class Element {
+    public:
+        enum Type {
+            None,
+            Key,
+            List,
+            Block
+        };
+
+        /**
+         * @param name   Case-independent name of the element.
+         */
+        Element(Type t = None, const String& n = "") : _type(t) { setName(n); }
+        virtual ~Element() {}
+
+        Type type() const { return _type; }
+        bool isKey() const { return _type == Key; }
+        bool isList() const { return _type == List; }
+        bool isBlock() const { return _type == Block; }
+        const String& name() const { return _name; }
+
+        void setName(const String& name) { _name = name.toLower(); }
+
+        virtual QStringList values() const = 0;
+
+    private:
+        Type _type;
+        String _name;
+    };
+
+    /**
+     * Element that contains a single string value.
+     */
+    class KeyElement : public Element {
+    public:
+        KeyElement(const String& name, const String& value) : Element(Key, name), _value(value) {}
+
+        void setValue(const String& v) { _value = v; }
+        const String& value() const { return _value; }
+
+        QStringList values() const {
+            QStringList list;
+            list << _value;
+            return list;
+        }
+
+    private:
+        String _value;
+    };
+
+    /**
+     * Element that contains a list of string values.
+     */
+    class ListElement : public Element {
+    public:
+        ListElement(const String& name) : Element(List, name) {}
+
+        void add(const String& v) { _values << v; }
+
+        QStringList values() const { return _values; }
+
+    private:
+        QStringList _values;
+    };
+
+    /**
+     * Contains other Elements, including other block elements. In addition to
+     * a name, each block may have a "block type", which is a case insensitive
+     * identifier.
+     */
+    class BlockElement : public Element {
+    public:
+        DENG2_ERROR(ValuesError)
+
+        typedef QHash<String, Element*> Contents;
+        typedef QList<Element*> ContentsInOrder;
+
+        BlockElement(const String& bType, const String& name) : Element(Block, name) {
+            setBlockType(bType);
+        }
+        ~BlockElement();
+
+        const String& blockType() const { return _blockType; }
+        const ContentsInOrder& contentsInOrder() const { return _contentsInOrder; }
+        const Contents& contents() const { return _contents; }
+
+        QStringList values() const {
+            throw ValuesError("Info::BlockElement::values",
+                              "Block elements do not contain text values (only other elements)");
+        }
+
+        int size() const { return _contents.size(); }
+        bool contains(const String& name) { return _contents.contains(name); }
+
+        void setBlockType(const String& bType) { _blockType = bType.toLower(); }
+        void clear();
+        void add(Element* elem) {
+            DENG2_ASSERT(elem != 0);
+            _contentsInOrder.append(elem);
+            _contents.insert(elem->name(), elem);
+        }
+
+        Element* find(const String& name) const {
+            Contents::const_iterator found = _contents.find(name);
+            if(found == _contents.end()) return 0;
+            return found.value();
+        }
+
+        /**
+         * Finds the value of a key inside the block. If the element is not a
+         * key element, returns an empty string.
+         *
+         * @param name  Name of a key element in the block.
+         */
+        String keyValue(const String& name) const {
+            Element* e = find(name);
+            if(!e || !e->isKey()) return "";
+            return static_cast<KeyElement*>(e)->value();
+        }
+
+    private:
+        String _blockType;
+        Contents _contents;
+        ContentsInOrder _contentsInOrder;
+    };
+
+public:
+    /// The parser encountered a syntax error in the source file. @ingroup errors
+    DENG2_ERROR(SyntaxError)
+
+public:
+    Info();
+
+    /**
+     * Deserializes the key/value data from text.
+     *
+     * @param infoSource  Info text.
+     */
+    Info(const String& infoSource);
+
+    ~Info();
+
+    const BlockElement& root() const;
+
+private:
+    struct Instance;
+    Instance* d;
+};
+
+} // namespace de
+
+#endif // LIBDENG2_INFO_H