diff options
Diffstat (limited to 'src/core/variant/Reader.cpp')
| -rw-r--r-- | src/core/variant/Reader.cpp | 114 |
1 files changed, 74 insertions, 40 deletions
diff --git a/src/core/variant/Reader.cpp b/src/core/variant/Reader.cpp index e9a58a1..a0bba52 100644 --- a/src/core/variant/Reader.cpp +++ b/src/core/variant/Reader.cpp @@ -29,21 +29,33 @@ namespace variant { static const char *ERR_UNEXPECTED_CHARACTER = "Unexpected character"; static const char *ERR_UNEXPECTED_END = "Unexpected end"; static const char *ERR_UNTERMINATED = "Unterminated literal"; +static const char *ERR_INVALID_ESCAPE = "Invalid escape sequence"; static const int STATE_INIT = 0; static const int STATE_IN_STRING = 1; static const int STATE_ESCAPE = 2; +static const int STATE_WHITESPACE = 3; -static std::pair<Err, std::string> parseString( - BufferedCharReader &reader, const unordered_set<char> *delims = nullptr, - Logger *logger = nullptr) +template <class T> +static std::pair<bool, T> error(BufferedCharReader &reader, Logger &logger, + const char *err, T res) +{ + logger.errorAt(err, reader); + return std::make_pair(false, std::move(res)); +} + +std::pair<bool, std::string> Reader::parseString( + BufferedCharReader &reader, Logger &logger, + const std::unordered_set<char> *delims) { // Initialize the internal state - Err errCode = Err::OK; int state = STATE_INIT; char quote = 0; std::stringstream res; + // Consume all whitespace + reader.consumeWhitespace(); + // Statemachine whic iterates over each character in the stream // TODO: Combination of peeking and consumePeek is stupid as consumePeek is // the default (read and putBack would obviously be better, yet the latter @@ -55,29 +67,28 @@ static std::pair<Err, std::string> parseString( if (c == '"' || c == '\'') { quote = c; state = STATE_IN_STRING; - } else if (delims && delims.count(c)) { - Logger.log(ERR_UNTERMINATED, reader); - return std::make_pair(Err::UNEXPECTED_END, res.str()); - } else if (Utils::isWhitespace(c)) { - reader.consumePeek(); - continue; + break; + } else if (delims && delims->count(c)) { + return error(reader, logger, ERR_UNEXPECTED_END, res.str()); } - return std::make_pair(Err::UNEXPECTED_CHARACTER, res.str()); - break; + return error(reader, logger, ERR_UNEXPECTED_CHARACTER, + res.str()); case STATE_IN_STRING: - if (c == q) { - state = STATE_END; + if (c == quote) { reader.consumePeek(); - return std::make_pair(Err::OK, res.str()); + return std::make_pair(true, res.str()); } else if (c == '\\') { state = STATE_ESCAPE; + reader.consumePeek(); + break; } else if (c == '\n') { - return std::make_pair(Err::UNTERMINATED, res.str()); + return error(reader, logger, ERR_UNTERMINATED, res.str()); } res << c; reader.consumePeek(); break; case STATE_ESCAPE: + // Handle all possible special escape characters switch (c) { case 'b': res << '\b'; @@ -118,67 +129,90 @@ static std::pair<Err, std::string> parseString( if (Utils::isNumeric(c)) { // TODO: Parse octal 000 sequence } else { - errCode = Err::ERR_INVALID_ESCAPE; + logger.errorAt(ERR_INVALID_ESCAPE, reader); } break; } + + // Switch back to the "normal" state state = STATE_IN_STRING; reader.consumePeek(); break; } } - return std::make_pair(Err::UNEXPECTED_END, res.str()); + return error(reader, logger, ERR_UNEXPECTED_END, res.str()); } -static std::pair<Err, std::string> parseUnescapedString( - BufferedCharReader &reader, const unordered_set<char> *delims) +std::pair<bool, std::string> Reader::parseUnescapedString( + BufferedCharReader &reader, Logger &logger, + const std::unordered_set<char> &delims) { - assert(delims); - std::stringstream res; + std::stringstream buf; char c; + + // Consume all whitespace + reader.consumeWhitespace(); + + // Copy all characters, skip whitespace at the end + int state = STATE_IN_STRING; while (reader.peek(&c)) { - if (delims->count(c)) { - return std::make_pair(Err::OK, res.str()); + if (delims.count(c)) { + return std::make_pair(true, res.str()); + } else if (Utils::isWhitespace(c)) { + // Do not add whitespace to the output buffer + state = STATE_WHITESPACE; + buf << c; + } else { + // If we just hat a sequence of whitespace, append it to the output + // buffer and continue + if (state == STATE_WHITESPACE) { + res << buf.str(); + buf.str(std::string{}); + buf.clear(); + state = STATE_IN_STRING; + } + res << c; } - res << c; reader.consumePeek(); } - return std::make_pair(Err::UNEXPECTED_END, res.str()); + return std::make_pair(true, res.str()); } -static std::pair<Err, Variant> parseGeneric(BufferedCharReader &reader, - const unordered_set<char> *delims) +std::pair<bool, Variant> Reader::parseGeneric( + BufferedCharReader &reader, Logger &logger, + const std::unordered_set<char> &delims) { - assert(delims); - char c; + + // Skip all whitespace characters + reader.consumeWhitespace(); + while (reader.peek(&c)) { - // Stop if a delimiter is reached, skipp all whitespace characters - if (delims->count(c)) { - return std::make_pair(Err::OK, res.str()); - } else if (Utils::isWhitespace(c)) { - reader.consumePeek(); - continue; + // Stop if a delimiter is reached + if (delims.count(c)) { + return error(reader, logger, ERR_UNEXPECTED_END, nullptr); } // Parse a string if a quote is reached if (c == '"' || c == '\'') { - return parseString(reader, nullptr); + auto res = parseString(reader, logger); + return std::make_pair(res.first, res.second.c_str()); } if (c == '[') { // TODO: Parse struct descriptor } - if (isNumeric(c)) { + if (Utils::isNumeric(c)) { // TODO: Parse integer/double } // Parse an unescaped string in any other case - return parseUnescapedString(reader, delims); + auto res = parseUnescapedString(reader, logger, delims); + return std::make_pair(res.first, res.second.c_str()); } - return std::make_pair(Err::UNEXPECTED_END, res.str()); + return error(reader, logger, ERR_UNEXPECTED_END, nullptr); } } } |