48 lines
870 B
C++
48 lines
870 B
C++
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#ifndef SCOPE_HPP
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#define SCOPE_HPP
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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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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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