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+/*
+ Ousía
+ Copyright (C) 2014 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 CodeTokenizer.hpp
+
+ * @author Benjamin Paaßen (bpaassen@techfak.uni-bielefeld.de)
+ */
+#ifndef _OUSIA_CODE_TOKENIZER_HPP_
+#define _OUSIA_CODE_TOKENIZER_HPP_
+
+#include <map>
+#include <sstream>
+
+#include <core/common/CharReader.hpp>
+#include "Tokenizer.hpp"
+
+namespace ousia {
+
+/*
+ * This enum contains all special Token the CodeTokenizer supports, namely:
+ *
+ * 1.) An ambigous Tokens - in post programming languages single-quotes ' or
+ * double-quotes " - to delimit string tokens.
+ * 2.) A start token for line comments, which would e.g. be // in Java.
+ * 3.) A start token for a block comment
+ * 4.) An end token for a block comment.
+ * 5.) A linebreak token
+ * 6.) The escape token, which would e.g. be \ in java.
+ */
+enum class CodeTokenMode {
+ STRING_START_END,
+ LINE_COMMENT,
+ BLOCK_COMMENT_START,
+ BLOCK_COMMENT_END,
+ LINEBREAK,
+ ESCAPE,
+ NONE
+};
+
+/**
+ * A CodeTokenDescriptor defines the id the user likes to have returned for
+ * a Token of the mode specified, e.g. if you want to get the id 4 for a
+ * String Token the corresponding CodeTokenDescriptor would be inizialized
+ * with CodeTokenDescriptor myDesc {CodeTokenMode::STRING_START_END, 4};
+ */
+struct CodeTokenDescriptor {
+ CodeTokenMode mode;
+ int id;
+
+ CodeTokenDescriptor(CodeTokenMode mode, int id) : mode(mode), id(id) {}
+};
+
+/**
+ * The CodeTokenizer is a finite state machine with the states NORMAL, being
+ * IN_BLOCK_COMMENT, being IN_LINE_COMMENT or being IN_STRING.
+ */
+enum class CodeTokenizerState {
+ NORMAL,
+ IN_BLOCK_COMMENT,
+ IN_LINE_COMMENT,
+ IN_STRING
+};
+
+/**
+ * The purpose of a CodeTokenizer is to make it easier to parse classical
+ * programming Code. It adds the following features to a regular Tokenizer:
+ * 1.) String tokens (e.g. "string" in Java Code) instead of 3 separate tokens
+ * for the opening delimiter, the text and the closing delimiter.
+ * 2.) Escaping in String tokens.
+ * 3.) Comment Tokens (for line comments as well as block comments)
+ */
+class CodeTokenizer : public Tokenizer {
+private:
+ std::map<int, CodeTokenDescriptor> descriptors;
+ CodeTokenizerState state;
+ std::stringstream buf;
+ Token startToken;
+ int returnTokenId;
+ bool escaped = false;
+
+ Token constructToken(const Token &t);
+ void buffer(const Token &t);
+
+protected:
+ bool doPrepare(const Token &t, std::deque<Token> &peeked) override;
+
+public:
+ /**
+ * If you do not want comment tokens to be returned you can set this to
+ * true.
+ */
+ bool ignoreComments = false;
+ /**
+ * If you do not want linebreaks to be returned you can set this to true.
+ */
+ bool ignoreLinebreaks = false;
+
+ /**
+ *
+ * @param input a CharReader containing the input for this tokenizer, as
+ * with a regular tokenizer.
+ * @param root a TokenTreeNode representing the root of the TokenTree.
+ * Please note that you have to specify all tokenIDs here that you use
+ * in the descriptors map.
+ * @param descriptors a map mapping tokenIDs to CodeTokenDescriptors.
+ * In this way you can specify the meaning of certain Tokens. Say you
+ * specified the Token "//" with the id 1 in the TokenTree. Then you could
+ * add the entry "1" with the Mode "LINE_COMMENT" to the descriptors map
+ * and this CodeTokenizer would recognize the token "//" as starting a
+ * line comment.
+ */
+ CodeTokenizer(CharReader &input, const TokenTreeNode &root,
+ std::map<int, CodeTokenDescriptor> descriptors)
+ : Tokenizer(input, root), descriptors(descriptors), state(CodeTokenizerState::NORMAL)
+ {
+ }
+};
+}
+
+#endif