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+/*
+ Ousía
+ Copyright (C) 2014, 2015 Benjamin Paaßen, Andreas Stöckel
+
+ 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 3 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 _OUSIA_PARSER_SCOPE_H_
+#define _OUSIA_PARSER_SCOPE_H_
+
+#include <core/Node.hpp>
+
+/**
+ * @file Scope.hpp
+ *
+ * Contains the Scope class used for resolving references based on the current
+ * parser state.
+ *
+ * @author Andreas Stöckel (astoecke@techfak.uni-bielefeld.de)
+ */
+
+namespace ousia {
+namespace parser {
+
+class Scope;
+
+/**
+ * The ScopedScope class takes care of pushing a Node instance into the
+ * name resolution stack of a Scope instance and poping this node once the
+ * ScopedScope instance is deletes. This way you cannot forget to pop a Node
+ * from a Scope instance as this operation is performed automatically.
+ */
+class ScopedScope {
+private:
+ /**
+ * Reference at the backing scope instance.
+ */
+ Scope *scope;
+
+public:
+ /**
+ * Creates a new ScopedScope instance.
+ *
+ * @param scope is the backing Scope instance.
+ * @param node is the Node instance that should be poped onto the stack of
+ * the Scope instance.
+ */
+ ScopedScope(Scope *scope, Handle<Node> node);
+
+ /**
+ * Pops the Node given in the constructor form the stack of the Scope
+ * instance.
+ */
+ ~ScopedScope();
+
+ /**
+ * Copying a ScopedScope is invalid.
+ */
+ ScopedScope(const ScopedScope &) = delete;
+
+ /**
+ * Move constructor of the ScopedScope class.
+ */
+ ScopedScope(ScopedScope &&);
+
+ /**
+ * Provides access at the underlying Scope instance.
+ */
+ Scope *operator->() { return scope; }
+
+ /**
+ * Provides access at the underlying Scope instance.
+ */
+ Scope &operator*() { return *scope; }
+};
+
+/**
+ * Provides an interface for document parsers to resolve references based on the
+ * current position in the created document tree. The Scope class itself is
+ * represented as a chain of Scope objects where each element has a reference to
+ * a Node object attached to it. The descend method can be used to add a new
+ * scope element to the chain.
+ */
+class Scope {
+private:
+ std::deque<Rooted<Node>> nodes;
+
+public:
+ /**
+ * Constructor of the Scope class.
+ *
+ * @param rootNode is the top-most Node from which elements can be looked
+ * up.
+ */
+ Scope(Handle<Node> rootNode) { nodes.push_back(rootNode); }
+
+ /**
+ * Returns a reference at the Manager instance all nodes belong to.
+ */
+ Manager &getManager() { return getRoot()->getManager(); }
+
+ /**
+ * Pushes a new node onto the scope.
+ *
+ * @param node is the node that should be used for local lookup.
+ */
+ void push(Handle<Node> node) { nodes.push_back(node); }
+
+ /**
+ * Removes the last pushed node from the scope.
+ */
+ void pop() { nodes.pop_back(); }
+
+ /**
+ * Returns a ScopedScope instance, which automatically pushes the given node
+ * into the Scope stack and pops it once the ScopedScope is destroyed.
+ */
+ ScopedScope descend(Handle<Node> node) { return ScopedScope{this, node}; }
+
+ /**
+ * Returns the top-most Node instance in the Scope hirarchy.
+ *
+ * @return a reference at the root node.
+ */
+ Rooted<Node> getRoot() { return nodes.front(); }
+
+ /**
+ * Returns the bottom-most Node instance in the Scope hirarchy, e.g. the
+ * node that was pushed last onto the stack.
+ *
+ * @return a reference at the leaf node.
+ */
+ Rooted<Node> getLeaf() { return nodes.back(); }
+};
+
+/* Class ScopedScope -- inline declaration of some methods */
+
+inline ScopedScope::ScopedScope(Scope *scope, Handle<Node> node) : scope(scope)
+{
+ scope->push(node);
+}
+
+inline ScopedScope::~ScopedScope()
+{
+ if (scope) {
+ scope->pop();
+ }
+}
+
+inline ScopedScope::ScopedScope(ScopedScope &&s)
+{
+ scope = s.scope;
+ s.scope = nullptr;
+}
+}
+}
+
+#endif /* _OUSIA_PARSER_SCOPE_H_ */
+