1 /* 2 * Copyright (C) 2018 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "utils/codepoint-range.h" 18 19 #include <algorithm> 20 21 namespace libtextclassifier3 { 22 23 // Returns a sorted list of the codepoint ranges. 24 void SortCodepointRanges( 25 const std::vector<const CodepointRange*>& codepoint_ranges, 26 std::vector<CodepointRangeStruct>* sorted_codepoint_ranges) { 27 sorted_codepoint_ranges->clear(); 28 sorted_codepoint_ranges->reserve(codepoint_ranges.size()); 29 for (const CodepointRange* range : codepoint_ranges) { 30 sorted_codepoint_ranges->push_back( 31 CodepointRangeStruct(range->start(), range->end())); 32 } 33 34 std::sort(sorted_codepoint_ranges->begin(), sorted_codepoint_ranges->end(), 35 [](const CodepointRangeStruct& a, const CodepointRangeStruct& b) { 36 return a.start < b.start; 37 }); 38 } 39 40 // Returns true if given codepoint is covered by the given sorted vector of 41 // codepoint ranges. 42 bool IsCodepointInRanges( 43 int codepoint, const std::vector<CodepointRangeStruct>& codepoint_ranges) { 44 auto it = std::lower_bound( 45 codepoint_ranges.begin(), codepoint_ranges.end(), codepoint, 46 [](const CodepointRangeStruct& range, int codepoint) { 47 // This function compares range with the 48 // codepoint for the purpose of finding the first 49 // greater or equal range. Because of the use of 50 // std::lower_bound it needs to return true when 51 // range < codepoint; the first time it will 52 // return false the lower bound is found and 53 // returned. 54 // 55 // It might seem weird that the condition is 56 // range.end <= codepoint here but when codepoint 57 // == range.end it means it's actually just 58 // outside of the range, thus the range is less 59 // than the codepoint. 60 return range.end <= codepoint; 61 }); 62 if (it != codepoint_ranges.end() && it->start <= codepoint && 63 it->end > codepoint) { 64 return true; 65 } else { 66 return false; 67 } 68 } 69 70 } // namespace libtextclassifier3 71
