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#include <fstream>
#include <iostream>
#include <vector>
#include <sstream>
#include <pog/parser.h>
using namespace pog;
struct NoData{};
using Value = std::variant<NoData, bool, int, double, std::string>;
struct Attribute
{
std::string key;
Value value;
};
struct Section
{
std::string name;
std::vector<Attribute> attributes;
};
struct Document
{
Section global;
std::vector<Section> sections;
};
void print_attributes(const Section& section)
{
for (const auto& attr : section.attributes)
{
fmt::print("{}::{}", section.name, attr.key);
std::visit(overloaded {
[](const NoData&) { fmt::print(" (no data)\n"); },
[](bool b) { fmt::print(" (bool) = {}\n", b); },
[](int i) { fmt::print(" (int) = {}\n", i); },
[](double d) { fmt::print(" (double) = {}\n", d); },
[](const std::string& s) { fmt::print(" (string) = {}\n", s); }
}, attr.value);
}
}
int main(int argc, char* argv[])
{
if (argc < 2)
{
fmt::print("Usage: {} INPUT_FILE\n", argv[0]);
return 1;
}
using ParserType = std::variant<
Value,
Attribute,
Section,
Document,
std::vector<Attribute>,
std::vector<Section>
>;
Parser<ParserType> p;
p.token(R"(\s+)");
p.token("\\[").symbol("[");
p.token("\\]").symbol("]");
p.token("=").symbol("=");
p.token(R"([0-9]+\.[0-9]+)").symbol("double").action([](std::string_view str) -> ParserType {
return std::stod(std::string{str});
});
p.token(R"([0-9]+)").symbol("int").action([](std::string_view str) -> ParserType {
return std::stoi(std::string{str});
});
p.token("(true|false)").symbol("bool").action([](std::string_view str) -> ParserType {
return str == "true";
});
p.token("[a-zA-Z0-9]+").symbol("id").fullword().action([](std::string_view str) -> ParserType {
return std::string{str};
});
p.set_start_symbol("root");
p.rule("root")
.production("attrs", "sections", [](auto&& args) -> ParserType {
return Document{
Section{std::string{}, std::get<std::vector<Attribute>>(args[0])},
std::get<std::vector<Section>>(args[1])
};
})
.production("attrs", [](auto&& args) -> ParserType {
return Document{
Section{std::string{}, std::get<std::vector<Attribute>>(args[0])},
std::vector<Section>{}
};
})
.production("sections", [](auto&& args) -> ParserType {
return Document{
Section{std::string{}, std::vector<Attribute>{}},
std::get<std::vector<Section>>(args[0])
};
})
.production([](auto&&) -> ParserType {
return Document{
Section{std::string{}, std::vector<Attribute>{}},
std::vector<Section>{}
};
});
p.rule("sections")
.production("sections", "section", [](auto&& args) -> ParserType {
std::get<std::vector<Section>>(args[0]).push_back(std::get<Section>(args[1]));
return std::move(args[0]);
})
.production("section", [](auto&& args) -> ParserType {
return std::vector<Section>{std::get<Section>(args[0])};
});
p.rule("section")
.production("[", "id", "]", "attrs", [](auto&& args) -> ParserType {
return Section{
std::get<std::string>(std::get<Value>(args[1])),
std::get<std::vector<Attribute>>(args[3])
};
});
p.rule("attrs")
.production("attrs", "attr", [](auto&& args) -> ParserType {
std::get<std::vector<Attribute>>(args[0]).push_back(std::get<Attribute>(args[1]));
return std::move(args[0]);
})
.production("attr", [](auto&& args) -> ParserType {
return std::vector<Attribute>{std::get<Attribute>(args[0])};
});
p.rule("attr").production("id", "=", "value", [](auto&& args) -> ParserType {
return Attribute{
std::get<std::string>(std::get<Value>(args[0])),
std::get<Value>(args[2])
};
});
p.rule("value")
.production("double", [](auto&& args) -> ParserType {
return std::move(args[0]);
})
.production("int", [](auto&& args) -> ParserType {
return std::move(args[0]);
})
.production("bool", [](auto&& args) -> ParserType {
return std::move(args[0]);
})
.production("id", [](auto&& args) -> ParserType {
return std::move(args[0]);
});
p.prepare();
std::ifstream input_file(argv[1]);
auto document = p.parse(input_file);
if (document)
{
const auto& d = document.value();
if (std::holds_alternative<Document>(d))
{
const auto& dd = std::get<Document>(d);
print_attributes(dd.global);
for (const auto& sect : dd.sections)
print_attributes(sect);
}
else
{
fmt::print("Parser error\n");
return 1;
}
}
else
{
fmt::print("Parser error\n");
return 1;
}
}
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