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https://github.com/NixOS/nix.git
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e4f62e4608
* It is tough to contribute to a project that doesn't use a formatter, * It is extra hard to contribute to a project which has configured the formatter, but ignores it for some files * Code formatting makes it harder to hide obscure / weird bugs by accident or on purpose, Let's rip the bandaid off? Note that PRs currently in flight should be able to be merged relatively easily by applying `clang-format` to their tip prior to merge.
113 lines
2.8 KiB
C++
113 lines
2.8 KiB
C++
#include "nix/util/suggestions.hh"
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#include "nix/util/ansicolor.hh"
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#include "nix/util/terminal.hh"
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#include <algorithm>
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#include <sstream>
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namespace nix {
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int levenshteinDistance(std::string_view first, std::string_view second)
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{
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// Implementation borrowed from
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// https://en.wikipedia.org/wiki/Levenshtein_distance#Iterative_with_two_matrix_rows
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int m = first.size();
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int n = second.size();
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auto v0 = std::vector<int>(n + 1);
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auto v1 = std::vector<int>(n + 1);
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for (auto i = 0; i <= n; i++)
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v0[i] = i;
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for (auto i = 0; i < m; i++) {
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v1[0] = i + 1;
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for (auto j = 0; j < n; j++) {
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auto deletionCost = v0[j + 1] + 1;
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auto insertionCost = v1[j] + 1;
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auto substitutionCost = first[i] == second[j] ? v0[j] : v0[j] + 1;
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v1[j + 1] = std::min({deletionCost, insertionCost, substitutionCost});
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}
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std::swap(v0, v1);
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}
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return v0[n];
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}
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Suggestions Suggestions::bestMatches(const StringSet & allMatches, std::string_view query)
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{
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std::set<Suggestion> res;
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for (const auto & possibleMatch : allMatches) {
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res.insert(
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Suggestion{
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.distance = levenshteinDistance(query, possibleMatch),
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.suggestion = possibleMatch,
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});
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}
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return Suggestions{res};
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}
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Suggestions Suggestions::trim(int limit, int maxDistance) const
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{
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std::set<Suggestion> res;
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int count = 0;
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for (auto & elt : suggestions) {
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if (count >= limit || elt.distance > maxDistance)
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break;
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count++;
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res.insert(elt);
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}
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return Suggestions{res};
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}
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std::string Suggestion::to_string() const
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{
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return ANSI_WARNING + filterANSIEscapes(suggestion) + ANSI_NORMAL;
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}
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std::string Suggestions::to_string() const
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{
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switch (suggestions.size()) {
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case 0:
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return "";
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case 1:
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return suggestions.begin()->to_string();
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default: {
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std::string res = "one of ";
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auto iter = suggestions.begin();
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res += iter->to_string(); // Iter can’t be end() because the container isn’t null
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iter++;
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auto last = suggestions.end();
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last--;
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for (; iter != suggestions.end(); iter++) {
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res += (iter == last) ? " or " : ", ";
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res += iter->to_string();
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}
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return res;
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}
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}
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}
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Suggestions & Suggestions::operator+=(const Suggestions & other)
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{
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suggestions.insert(other.suggestions.begin(), other.suggestions.end());
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return *this;
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}
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std::ostream & operator<<(std::ostream & str, const Suggestion & suggestion)
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{
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return str << suggestion.to_string();
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}
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std::ostream & operator<<(std::ostream & str, const Suggestions & suggestions)
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{
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return str << suggestions.to_string();
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}
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} // namespace nix
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