| // Copyright 2022 The Tint Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include <algorithm> |
| |
| #include "src/tint/utils/string.h" |
| #include "src/tint/utils/vector.h" |
| |
| namespace tint::utils { |
| |
| size_t Distance(std::string_view str_a, std::string_view str_b) { |
| const auto len_a = str_a.size(); |
| const auto len_b = str_b.size(); |
| |
| Vector<size_t, 64> mat; |
| mat.Reserve((len_a + 1) * (len_b + 1)); |
| |
| auto at = [&](size_t a, size_t b) -> size_t& { return mat[a + b * (len_a + 1)]; }; |
| |
| at(0, 0) = 0; |
| for (size_t a = 1; a <= len_a; a++) { |
| at(a, 0) = a; |
| } |
| for (size_t b = 1; b <= len_b; b++) { |
| at(0, b) = b; |
| } |
| for (size_t b = 1; b <= len_b; b++) { |
| for (size_t a = 1; a <= len_a; a++) { |
| bool eq = str_a[a - 1] == str_b[b - 1]; |
| at(a, b) = std::min({ |
| at(a - 1, b) + 1, |
| at(a, b - 1) + 1, |
| at(a - 1, b - 1) + (eq ? 0 : 1), |
| }); |
| } |
| } |
| return at(len_a, len_b); |
| } |
| |
| void SuggestAlternatives(std::string_view got, |
| Slice<char const* const> strings, |
| utils::StringStream& ss) { |
| // If the string typed was within kSuggestionDistance of one of the possible enum values, |
| // suggest that. Don't bother with suggestions if the string was extremely long. |
| constexpr size_t kSuggestionDistance = 5; |
| constexpr size_t kSuggestionMaxLength = 64; |
| if (!got.empty() && got.size() < kSuggestionMaxLength) { |
| size_t candidate_dist = kSuggestionDistance; |
| const char* candidate = nullptr; |
| for (auto* str : strings) { |
| auto dist = utils::Distance(str, got); |
| if (dist < candidate_dist) { |
| candidate = str; |
| candidate_dist = dist; |
| } |
| } |
| if (candidate) { |
| ss << "Did you mean '" << candidate << "'?\n"; |
| } |
| } |
| |
| // List all the possible enumerator values |
| ss << "Possible values: "; |
| for (auto* str : strings) { |
| if (str != strings[0]) { |
| ss << ", "; |
| } |
| ss << "'" << str << "'"; |
| } |
| } |
| |
| } // namespace tint::utils |