71 lines
1.6 KiB
C++
71 lines
1.6 KiB
C++
#ifndef SCOPE_HPP
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#define SCOPE_HPP
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/*
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* Monicelli: an esoteric language compiler
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*
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* Copyright (C) 2014 Stefano Sanfilippo
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <boost/optional.hpp>
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#include <boost/range/adaptor/reversed.hpp>
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#include <vector>
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#include <unordered_map>
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namespace monicelli {
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template<class Key, class Value>
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class Scope {
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public:
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boost::optional<Value> lookup(Key name) {
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for (auto const& table: boost::adaptors::reverse(tables)) {
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auto result = table.find(name);
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if (result != table.end()) {
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return result->second;
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}
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}
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return boost::none;
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}
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void push(Key const& key, Value const& value) {
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tables.back().insert({key, value});
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}
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void enter() {
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tables.emplace_back();
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}
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void leave() {
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if (!tables.empty()) {
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tables.pop_back();
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}
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}
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void drop() {
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tables.clear();
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}
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private:
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std::vector<std::unordered_map<Key, Value>> tables;
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};
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}
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#endif
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