According to my lords holy command I enacted his graces order of moving all peasants and lordlings, big and small, young and old, to our common land and inner sanctuary to be safe from outer threats by those usurpers.

1 files changed, 212 insertions, 0 deletions

diff --git a/src/core/Tokenizer.cpp b/src/core/Tokenizer.cpp
new file mode 100644
index 0000000..a0ca3aa
--- /dev/null
+++ b/src/core/Tokenizer.cpp
@@ -0,0 +1,212 @@
+/*
+    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 <sstream>
+
+#include "Tokenizer.hpp"
+
+namespace ousia {
+namespace utils {
+
+static std::map<char, TokenTreeNode> buildChildren(
+    const std::map<std::string, int> &inputs)
+{
+	std::map<char, TokenTreeNode> children;
+	std::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 = TOKEN_NONE;
+	for (auto &e : inputs) {
+		if (e.first.empty()) {
+			if (tokenId != TOKEN_NONE) {
+				throw TokenizerException{std::string{"Ambigous token found: "} +
+				                         std::to_string(e.second)};
+			} else {
+				tokenId = e.second;
+			}
+		}
+	}
+	return tokenId;
+}
+
+TokenTreeNode::TokenTreeNode(const std::map<std::string, int> &inputs)
+    : children(buildChildren(inputs)), tokenId(buildId(inputs))
+{
+}
+
+Tokenizer::Tokenizer(BufferedCharReader &input, const TokenTreeNode &root)
+    : input(input), root(root)
+{
+}
+
+bool Tokenizer::prepare()
+{
+	std::stringstream buffer;
+	char c;
+	int startColumn = input.getColumn();
+	int startLine = input.getLine();
+	bool bufEmpty = true;
+	while (input.peek(&c)) {
+		if (root.children.find(c) != root.children.end()) {
+			// if there might be a special token, keep peeking forward
+			// until we find the token (or we don't).
+			TokenTreeNode const *n = &root;
+			std::stringstream tBuf;
+			int match = TOKEN_NONE;
+			while (true) {
+				tBuf << c;
+				n = &(n->children.at(c));
+				if (n->tokenId != TOKEN_NONE) {
+					match = n->tokenId;
+					// from here on we found a token. If we have something
+					// in our buffer already, we end the search now.
+					if (!bufEmpty) {
+						break;
+					} else {
+						// if we want to return this token ( = we have nothing
+						// in our buffer yet) we look greedily for the longest
+						// possible token we can construct.
+						input.consumePeek();
+					}
+				}
+				if (!input.peek(&c)) {
+					// if we are at the end we break off the search.
+					break;
+				}
+				if (n->children.find(c) == n->children.end()) {
+					// if we do not find a possible continuation anymore,
+					// break off the search.
+					break;
+				}
+			}
+			//reset the peek pointer to the last valid position.
+			input.resetPeek();
+			// check if we did indeed find a special token.
+			if (match != TOKEN_NONE) {
+				if (bufEmpty) {
+					// if we did not have text before, construct that token.
+					if (doPrepare(
+					        Token{match, tBuf.str(), startColumn, startLine,
+					              input.getColumn(), input.getLine()},
+					        peeked)) {
+						return true;
+					} else {
+						startColumn = input.getColumn();
+						startLine = input.getLine();
+						continue;
+					}
+				} else {
+					// otherwise we return the text before the token.
+					if (doPrepare(Token{TOKEN_TEXT, buffer.str(), startColumn,
+					                    startLine, input.getColumn(),
+					                    input.getLine()},
+					              peeked)) {
+						return true;
+					} else{
+						//we need to clear the buffer here. After all the token
+						//corresponding to this buffer segment is already
+						//constructed.
+						buffer.str(std::string());
+						bufEmpty = true;
+						startColumn = input.getColumn();
+						startLine = input.getLine();
+						continue;
+					} 
+				}
+			} else{
+				//if we found nothing, read at least one character.
+				input.peek(&c);
+			}
+		}
+		buffer << c;
+		bufEmpty = false;
+		input.consumePeek();
+	}
+	if (!bufEmpty) {
+		return doPrepare(Token{TOKEN_TEXT, buffer.str(), startColumn, startLine,
+		                       input.getColumn(), input.getLine()},
+		                 peeked);
+	}
+	return false;
+}
+
+bool Tokenizer::doPrepare(const Token &t, std::deque<Token> &peeked)
+{
+	peeked.push_back(t);
+	return true;
+}
+
+bool Tokenizer::next(Token &t)
+{
+	if (peeked.empty()) {
+		if (!prepare()) {
+			return false;
+		}
+	}
+	t = peeked.front();
+	peeked.pop_front();
+	resetPeek();
+	return true;
+}
+
+bool Tokenizer::peek(Token &t)
+{
+	if (peekCursor >= peeked.size()) {
+		if (!prepare()) {
+			return false;
+		}
+	}
+	t = peeked[peekCursor];
+	return true;
+}
+
+void Tokenizer::resetPeek() { peekCursor = 0; }
+
+void Tokenizer::consumePeek()
+{
+	while (peekCursor > 0) {
+		peeked.pop_front();
+		peekCursor--;
+	}
+}
+}
+}