1 /* 2 * Copyright (C) 2015 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 #ifndef _INIT_KEYWORD_MAP_H_ 18 #define _INIT_KEYWORD_MAP_H_ 19 20 #include <map> 21 #include <string> 22 23 #include <android-base/stringprintf.h> 24 25 template <typename Function> 26 class KeywordMap { 27 public: 28 using FunctionInfo = std::tuple<std::size_t, std::size_t, Function>; 29 using Map = const std::map<std::string, FunctionInfo>; 30 ~KeywordMap()31 virtual ~KeywordMap() { 32 } 33 FindFunction(const std::string & keyword,size_t num_args,std::string * err)34 const Function FindFunction(const std::string& keyword, 35 size_t num_args, 36 std::string* err) const { 37 using android::base::StringPrintf; 38 39 auto function_info_it = map().find(keyword); 40 if (function_info_it == map().end()) { 41 *err = StringPrintf("invalid keyword '%s'", keyword.c_str()); 42 return nullptr; 43 } 44 45 auto function_info = function_info_it->second; 46 47 auto min_args = std::get<0>(function_info); 48 auto max_args = std::get<1>(function_info); 49 if (min_args == max_args && num_args != min_args) { 50 *err = StringPrintf("%s requires %zu argument%s", 51 keyword.c_str(), min_args, 52 (min_args > 1 || min_args == 0) ? "s" : ""); 53 return nullptr; 54 } 55 56 if (num_args < min_args || num_args > max_args) { 57 if (max_args == std::numeric_limits<decltype(max_args)>::max()) { 58 *err = StringPrintf("%s requires at least %zu argument%s", 59 keyword.c_str(), min_args, 60 min_args > 1 ? "s" : ""); 61 } else { 62 *err = StringPrintf("%s requires between %zu and %zu arguments", 63 keyword.c_str(), min_args, max_args); 64 } 65 return nullptr; 66 } 67 68 return std::get<Function>(function_info); 69 } 70 71 private: 72 //Map of keyword -> 73 //(minimum number of arguments, maximum number of arguments, function pointer) 74 virtual Map& map() const = 0; 75 }; 76 77 #endif 78