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#pragma once
///@file
#include "comparator.hh"
#include <set>
#include <string_view>
#include <string>
#include <variant>
namespace nix {
int levenshteinDistance(std::string_view first, std::string_view second);
/**
* A potential suggestion for the cli interface.
*/
class Suggestion {
public:
/// The smaller the better
int distance;
std::string suggestion;
std::string to_string() const;
GENERATE_CMP(Suggestion, me->distance, me->suggestion)
};
class Suggestions {
public:
std::set<Suggestion> suggestions;
std::string to_string() const;
Suggestions trim(
int limit = 5,
int maxDistance = 2
) const;
static Suggestions bestMatches (
std::set<std::string> allMatches,
std::string query
);
Suggestions& operator+=(const Suggestions & other);
};
std::ostream & operator<<(std::ostream & str, const Suggestion &);
std::ostream & operator<<(std::ostream & str, const Suggestions &);
/**
* Either a value of type `T`, or some suggestions
*/
template<typename T>
class OrSuggestions {
public:
using Raw = std::variant<T, Suggestions>;
Raw raw;
T* operator ->()
{
return &**this;
}
T& operator *()
{
return std::get<T>(raw);
}
operator bool() const noexcept
{
return std::holds_alternative<T>(raw);
}
OrSuggestions(T t)
: raw(t)
{
}
OrSuggestions()
: raw(Suggestions{})
{
}
static OrSuggestions<T> failed(const Suggestions & s)
{
auto res = OrSuggestions<T>();
res.raw = s;
return res;
}
static OrSuggestions<T> failed()
{
return OrSuggestions<T>::failed(Suggestions{});
}
const Suggestions & getSuggestions()
{
static Suggestions noSuggestions;
if (const auto & suggestions = std::get_if<Suggestions>(&raw))
return *suggestions;
else
return noSuggestions;
}
};
}
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