From 73cc54cbf494d9da61b640035f25ad9c5eb86d84 Mon Sep 17 00:00:00 2001
From: Benjamin Paassen <bpaassen@techfak.uni-bielefeld.de>
Date: Fri, 31 Oct 2014 12:39:39 +0000
Subject: added tokenizer class code.

git-svn-id: file:///var/local/svn/basicwriter@87 daaaf23c-2e50-4459-9457-1e69db5a47bf
---
 src/core/utils/Tokenizer.cpp | 76 ++++++++++++++++++++++++++++++++++++++++++
 src/core/utils/Tokenizer.hpp | 78 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 154 insertions(+)
 create mode 100644 src/core/utils/Tokenizer.cpp
 create mode 100644 src/core/utils/Tokenizer.hpp

diff --git a/src/core/utils/Tokenizer.cpp b/src/core/utils/Tokenizer.cpp
new file mode 100644
index 0000000..1a84f0c
--- /dev/null
+++ b/src/core/utils/Tokenizer.cpp
@@ -0,0 +1,76 @@
+/*
+    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/>.
+*/
+
+#include "Tokenizer.hpp"
+
+namespace ousia {
+namespace utils {
+
+static std::unordered_map<char, TokenTreeNode> buildChildren(
+    const std::map<std::string, int> &inputs)
+{
+	std::std::unordered_map<char, TokenTreeNode> children;
+	std::unordered_map<char, std::map<std::string, int>> nexts;
+
+	for (auto &e : inputs) {
+		const std::string &s = e.first;
+		const int id = e.second;
+		if (s.empty()) {
+			continue;
+		}
+		char start = s[0];
+		const std::string suffix = s.substr(1);
+		if (nexts.find(start) != nexts.end()) {
+			nexts[start].insert(std::make_pair(suffix, id));
+		} else {
+			nexts.insert(std::make_pair(
+			    start, std::map<std::string, int>{{suffix, id}}));
+		}
+	}
+
+	for (auto &n : nexts) {
+		children.insert(std::make_pair(n.first, TokenTreeNode{n.second}));
+	}
+
+	return children;
+}
+
+static int buildId(const std::map<std::string, int> &inputs)
+{
+	int tokenId = -1;
+	for (auto &e : inputs) {
+		if (e.first.empty()) {
+			if (tokenId != -1) {
+				throw TokenizerException{std::string{"Ambigous token found: "} +
+				                         e.second};
+			} else {
+				tokenId = e.second;
+			}
+		}
+	}
+	return tokenId;
+}
+
+TokenTreeNode::TokenTreeNode(const std::map<std::string, int> &inputs)
+    : children(buildChildren(inputs), tokenId(buildId(inputs)))
+{
+}
+
+}
+}
+
diff --git a/src/core/utils/Tokenizer.hpp b/src/core/utils/Tokenizer.hpp
new file mode 100644
index 0000000..1d0db43
--- /dev/null
+++ b/src/core/utils/Tokenizer.hpp
@@ -0,0 +1,78 @@
+/*
+    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/>.
+*/
+
+#ifndef _OUSIA_UTILS_TOKENIZER_HPP_
+#define _OUSIA_UTILS_TOKENIZER_HPP_
+
+#include <istream>
+#include <unordered_map>
+#include <queue>
+
+namespace ousia {
+namespace utils {
+
+class TokenizerException : public std::exception {
+public:
+	const std::string msg;
+
+	ArgumentValidatorError(const std::string &msg) : msg(msg){};
+
+	virtual const char *what() const noexcept override { return msg.c_str(); }
+};
+
+class TokenTreeNode {
+public:
+	const std::unordered_map<char, TokenTreeNode> children;
+	const int tokenId;
+
+	TokenTreeNode(const std::map<std::string, int> &inputs);
+};
+
+struct Token {
+	const int tokenId;
+	const std::string content;
+	const int column;
+	const int line;
+
+	Token(int tokenId, std::string content, int column, int line)
+	    : tokenId(tokenId), content(content), column(column), line(line)
+	{
+	}
+};
+
+class Tokenizer {
+private:
+	const std::istream &input;
+	const TokenTreeNode root;
+	const std::queue<Token> peek;
+
+public:
+	Tokenizer(const TokenTreeNode &root, std::istream &input);
+
+	bool hasNext();
+
+	const Token &next();
+
+	const Token &peek();
+
+	void reset();
+};
+}
+}
+
+#endif
-- 
cgit v1.2.3