1 files changed, 171 insertions, 0 deletions
diff --git a/src/core/parser/stack/State.cpp b/src/core/parser/stack/State.cpp
new file mode 100644
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+++ b/src/core/parser/stack/State.cpp
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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/>.
+*/
+
+#include "State.hpp"
+
+namespace ousia {
+namespace parser_stack {
+
+/* Class State */
+
+State::State() : elementHandler(nullptr) {}
+
+State::State(StateSet parents, Arguments arguments,
+                         RttiSet createdNodeTypes,
+                         HandlerConstructor elementHandler,
+                         bool supportsAnnotations)
+    : parents(parents),
+      arguments(arguments),
+      createdNodeTypes(createdNodeTypes),
+      elementHandler(elementHandler),
+      supportsAnnotations(supportsAnnotations)
+{
+}
+
+State::State(const StateBuilder &builder)
+    : State(builder.build())
+{
+}
+
+/* Class StateBuilder */
+
+StateBuilder &StateBuilder::copy(const State &state)
+{
+	this->state = state;
+	return *this;
+}
+
+StateBuilder &StateBuilder::parent(const State *parent)
+{
+	state.parents = StateSet{parent};
+	return *this;
+}
+
+StateBuilder &StateBuilder::parents(const StateSet &parents)
+{
+	state.parents = parents;
+	return *this;
+}
+
+StateBuilder &StateBuilder::arguments(const Arguments &arguments)
+{
+	state.arguments = arguments;
+	return *this;
+}
+
+StateBuilder &StateBuilder::createdNodeType(const Rtti *type)
+{
+	state.createdNodeTypes = RttiSet{type};
+	return *this;
+}
+
+StateBuilder &StateBuilder::createdNodeTypes(const RttiSet &types)
+{
+	state.createdNodeTypes = types;
+	return *this;
+}
+
+StateBuilder &StateBuilder::elementHandler(
+    HandlerConstructor elementHandler)
+{
+	state.elementHandler = elementHandler;
+	return *this;
+}
+
+StateBuilder &StateBuilder::supportsAnnotations(bool supportsAnnotations)
+{
+	state.supportsAnnotations = supportsAnnotations;
+	return *this;
+}
+
+const State &StateBuilder::build() const { return state; }
+
+/* Class StateDeductor */
+
+StateDeductor::StateDeductor(
+    std::vector<const Rtti *> signature,
+    std::vector<const State *> states)
+    : tbl(signature.size()),
+      signature(std::move(signature)),
+      states(std::move(states))
+{
+}
+
+bool StateDeductor::isActive(size_t d, const State *s)
+{
+	// Lookup the "active" state of (d, s), if it was not already set
+	// (e.second is true) we'll have to calculate it
+	auto e = tbl[d].emplace(s, false);
+	bool &res = e.first->second;
+	if (!e.second) {
+		return res;
+	}
+
+	// Check whether this node is generative (may have produced the Node
+	// described by the current Signature element)
+	bool isGenerative = signature[d]->isOneOf(s->createdNodeTypes);
+
+	if (isGenerative && d == 0) {
+		// End of recursion -- the last signature element is reached and the
+		// node was generative
+		res = true;
+	} else {
+		// Try repetition of this node
+		if (isGenerative && isActive(d - 1, s)) {
+			res = true;
+		} else {
+			// Check whether any of the parent nodes were active -- either for
+			// the previous element (if this one is generative) or for the
+			// current element (assuming this node was not generative)
+			for (const State *parent : s->parents) {
+				if ((isGenerative && isActive(d - 1, parent)) ||
+					isActive(d, parent)) {
+					res = true;
+					break;
+				}
+			}
+		}
+	}
+
+	return res;
+}
+
+std::vector<const State *> StateDeductor::deduce()
+{
+	std::vector<const State *> res;
+	if (!signature.empty()) {
+		const size_t D = signature.size();
+		for (auto s : states) {
+			if (signature[D - 1]->isOneOf(s->createdNodeTypes) &&
+			    isActive(D - 1, s)) {
+				res.push_back(s);
+			}
+		}
+	}
+	return res;
+}
+
+/* Constant initializations */
+
+namespace States {
+const State All;
+const State None;
+}
+}
+}
+