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Diffstat (limited to 'src/core/common/VariantReader.hpp')
| -rw-r--r-- | src/core/common/VariantReader.hpp | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/src/core/common/VariantReader.hpp b/src/core/common/VariantReader.hpp new file mode 100644 index 0000000..5e7c5d2 --- /dev/null +++ b/src/core/common/VariantReader.hpp @@ -0,0 +1,166 @@ +/* + Ousía + Copyright (C) 2014, 2015 Benjamin Paaßen, Andreas Stöckel + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +/** + * @file VariantReader.hpp + * + * Provides parsers for various micro formats. These formats include integers, + * doubles, strings, JSON and the Ousía struct notation. + * + * @author Andreas Stöckel (astoecke@techfak.uni-bielefeld.de) + */ + +#ifndef _OUSIA_VARIANT_READER_HPP_ +#define _OUSIA_VARIANT_READER_HPP_ + +#include <cstdint> +#include <unordered_set> +#include <utility> + +#include "CharReader.hpp" +#include "Logger.hpp" +#include "Variant.hpp" + +namespace ousia { + +class VariantReader { +private: + /** + * Parses a string which may either be enclosed by " or ', unescapes + * entities in the string as specified for JavaScript. + * + * @param VariantReader is a reference to the CharReader instance which is + * the source for the character data. The VariantReader will be positioned + * after the terminating quote character or at the terminating delimiting + * character. + * @param logger is the logger instance that should be used to log error + * messages and warnings. + * @param delims is an optional set of delimiters after which parsing has to + * be stopped (the delimiters may occur inside the actual string, but not + * outside). If nullptr is given, no delimiter is used and a complete string + * is read. + */ + static std::pair<bool, std::string> parseString( + CharReader &VariantReader, Logger &logger, + const std::unordered_set<char> *delims); + +public: + /** + * Parses a string which may either be enclosed by " or ', unescapes + * entities in the string as specified for JavaScript. + * + * @param VariantReader is a reference to the CharReader instance which is + * the source for the character data. The VariantReader will be positioned + * after the terminating quote character or at the terminating delimiting + * character. + * @param logger is the logger instance that should be used to log error + * messages and warnings. + * @param delims is a set of delimiters after which parsing has to + * be stopped (the delimiters may occur inside the actual string, but not + * outside). + */ + static std::pair<bool, std::string> parseString( + CharReader &VariantReader, Logger &logger, + const std::unordered_set<char> &delims) + { + return parseString(VariantReader, logger, &delims); + } + + /** + * Parses a string which may either be enclosed by " or ', unescapes + * entities in the string as specified for JavaScript. + * + * @param VariantReader is a reference to the CharReader instance which is + * the source for the character data. The VariantReader will be positioned + * after the terminating quote character or at the terminating delimiting + * character. + * @param logger is the logger instance that should be used to log error + * messages and warnings. + */ + static std::pair<bool, std::string> parseString(CharReader &VariantReader, + Logger &logger) + { + return parseString(VariantReader, logger, nullptr); + } + + /** + * Extracts an unescaped string from the given buffered char VariantReader + * instance. This function just reads text until one of the given delimiter + * characters is reached. + * + * @param VariantReader is a reference to the CharReader instance which is + * the source for the character data. The VariantReader will be positioned + * at the terminating delimiting character. + * @param delims is a set of characters which will terminate the string. + * These characters are not included in the result. May not be nullptr. + */ + static std::pair<bool, std::string> parseUnescapedString( + CharReader &VariantReader, Logger &logger, + const std::unordered_set<char> &delims); + + /** + * Parses an integer from the given buffered char VariantReader instance + * until one of the given delimiter characters is reached. + * + * @param VariantReader is a reference to the CharReader instance from + * which the character data should been VariantReader. The VariantReader + * will be positioned at the terminating delimiting character or directly + * after the integer. + */ + static std::pair<bool, int64_t> parseInteger( + CharReader &VariantReader, Logger &logger, + const std::unordered_set<char> &delims); + + /** + * Parses an double from the given buffered char VariantReader instance + * until one of the given delimiter characters is reached. + * + * @param VariantReader is a reference to the CharReader instance from + * which the character data should been VariantReader. The VariantReader + * will be positioned at the terminating delimiting character or directly + * after the integer. + */ + static std::pair<bool, double> parseDouble( + CharReader &VariantReader, Logger &logger, + const std::unordered_set<char> &delims); + + /** + * Parses an array of values. + */ + static std::pair<bool, Variant::arrayType> parseArray( + CharReader &VariantReader, Logger &logger, char delim = 0); + + /** + * Tries to parse the most specific item from the given stream until one of + * the given delimiters is reached or a meaningful literal has been read. + * The resulting variant represents the value that has been read. + * + * @param VariantReader is a reference to the CharReader instance which is + * the source for the character data. The VariantReader will be positioned + * at the terminating delimiting character. + * @param delims is a set of characters which will terminate the string. + * These characters are not included in the result. May not be nullptr. + */ + static std::pair<bool, Variant> parseGeneric( + CharReader &VariantReader, Logger &logger, + const std::unordered_set<char> &delims); +}; +} + +#endif /* _OUSIA_VARIANT_READER_HPP_ */ + |