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Diffstat (limited to 'src/core/parser/Scope.hpp')
-rw-r--r-- | src/core/parser/Scope.hpp | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/src/core/parser/Scope.hpp b/src/core/parser/Scope.hpp new file mode 100644 index 0000000..0c37fbd --- /dev/null +++ b/src/core/parser/Scope.hpp @@ -0,0 +1,170 @@ +/* + 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_ */ + |