added some escape sequences to the SRE parser

.gitignore

@@ -13,3 +13,8 @@ hs_err_pid*
 
 # maven build
 /target/
+
+# eclipse
+.classpath
+.project
+.settings/

src/main/java/de/uni_stuttgart/beehts/model/DTMC.java

@@ -47,9 +47,9 @@ public class DTMC {
 	private Set<Node> finalNodes = new HashSet<>();
 
 	/**
-	 * Creates an "empty" DTMC, that is, a DTMC with an initial node that is
-	 * final and has no edges associated. The only String that can be recognized
-	 * by this machine is the empty string.
+	 * Creates an "empty" DTMC, that is, a DTMC with an initial node that is final
+	 * and has no edges associated. The only String that can be recognized by this
+	 * machine is the empty string.
 	 * 
 	 * @return an empty DTMC.
 	 */
@@ -164,8 +164,8 @@ public Set<Node> getFinalNodes() {
 	}
 
 	/**
-	 * Add a new node to the DTMC. The name may be modified if a node with this
-	 * name does already exist.
+	 * Add a new node to the DTMC. The name may be modified if a node with this name
+	 * does already exist.
 	 * 
 	 * @return the newly created node. You may modify the node afterwards, if
 	 *         necessary.
@@ -210,8 +210,7 @@ private Node addNodeNoCheck(Node n) {
 	/**
 	 * Add a new node to the DTMC and make it final.
 	 * 
-	 * @return The created node. You may modify the node afterwards, if
-	 *         necessary.
+	 * @return The created node. You may modify the node afterwards, if necessary.
 	 */
 	public Node addFinalNode(String name) {
 		Node n = addNode(name);
@@ -239,7 +238,7 @@ public void removeNode(Node n) {
 		removeEdges(getIncomingEdges(n));
 		removeEdges(getOutgoingEdges(n));
 		this.finalNodes.remove(n);
-		this.nodes.remove(n);
+		this.nodes.getReverseView().remove(n);
 		freeNodeNames.add(n.index);
 	}
 
@@ -282,10 +281,14 @@ public Edge addEdge(Node from, Node to, String character, double probability) {
 	 *            the edge to add.
 	 */
 	public void addEdge(Edge e) {
-		if (!this.nodes.getReverseView().containsKey(e.from) || !this.nodes.getReverseView().containsKey(e.to)
-				|| this.getEdges().contains(e) || this.getFinalNodes().contains(e.from)) {
-			throw new IllegalArgumentException();
+		if (!this.nodes.getReverseView().containsKey(e.from) || !this.nodes.getReverseView().containsKey(e.to)) {
+			throw new IllegalArgumentException("1 or both of the nodes are not in this DTMC. Add them first.");
+		} else if (this.getEdges().contains(e)) {
+			throw new IllegalArgumentException("Edge has already been added.");
+		} else if (this.getFinalNodes().contains(e.from)) {
+			throw new IllegalArgumentException("No outgoing edges for final nodes allowed.");
 		}
+
 		edges.add(e);
 		incoming.get(e.to).add(e);
 		outgoing.get(e.from).add(e);
@@ -323,8 +326,8 @@ public void removeEdges(Collection<Edge> edges) {
 	}
 
 	/**
-	 * Replace the inital node by n. Note that the old initial node will still
-	 * exist in the DTMC, but it is not inital anymore.
+	 * Replace the inital node by n. Note that the old initial node will still exist
+	 * in the DTMC, but it is not inital anymore.
 	 * 
 	 * @param n
 	 *            The node to make initial.
@@ -383,23 +386,22 @@ public void clearFinalNodes() {
 
 	/**
 	 * Adds the nodes and edges of the other DTMC to the this object. Will not
-	 * change the other DTMC. Will not change the initial node. Will add the
-	 * final nodes of other to the final node set. Note that you need to make
-	 * the attached DTMC accessible from the initial node by yourself, if you
-	 * want so.
+	 * change the other DTMC. Will not change the initial node. Will add the final
+	 * nodes of other to the final node set. Note that you need to make the attached
+	 * DTMC accessible from the initial node by yourself, if you want so.
 	 * 
 	 * @param other
 	 *            the other DTMC.
-	 * @return a map from the original nodes in other to the new nodes in the
-	 *         this object.
+	 * @return a map from the original nodes in other to the new nodes in the this
+	 *         object.
 	 */
 	public Map<Node, Node> attachOther(DTMC other) {
 		Map<Node, Node> retVal = new HashMap<>();
 
 		other.getNodes().stream().forEachOrdered(n -> retVal.put(n, this.addNode(n.name)));
 		other.getFinalNodes().stream().forEach(n -> this.makeNodeFinal(retVal.get(n)));
-		other.getEdges().stream()
-				.forEach(e -> this.addEdge(retVal.get(e.from), retVal.get(e.to), e.character, e.getProbability()));
+		other.getEdges().stream().forEach(
+				e -> this.addEdge(retVal.get(e.from), retVal.get(e.to), e.character, e.getProbability()));
 
 		return retVal;
 	}
@@ -414,8 +416,8 @@ public Map<Node, Node> attachOther(DTMC other) {
 	 */
 	public void simplify() {
 		// strip epsilon edges, wherever possible
-		Set<Edge> epsilonEdges = this.getEdges().stream().filter(e -> "".equals(e.character))
-				.collect(Collectors.toSet());
+		Set<Edge> epsilonEdges = this.getEdges().stream().filter(e -> "".equals(e.character)).collect(
+				Collectors.toSet());
 		epsilonEdges.forEach(e1 -> {
 			if (!this.getFinalNodes().contains(e1.to)) {
 				this.getOutgoingEdges(e1.to).forEach(e2 -> {
@@ -452,9 +454,8 @@ public void simplify() {
 	}
 
 	/**
-	 * Create a deep copy of this DTMC. That means that modifications of the
-	 * copy will not propagate back to the original DTMC (and the other way
-	 * round).
+	 * Create a deep copy of this DTMC. That means that modifications of the copy
+	 * will not propagate back to the original DTMC (and the other way round).
 	 * 
 	 * @return A deep copy of this DTMC.
 	 */
@@ -514,8 +515,7 @@ public static class Edge {
 		private double probability;
 
 		/**
-		 * Constructor. Initializes the final fields and does some sanity
-		 * checks.
+		 * Constructor. Initializes the final fields and does some sanity checks.
 		 * 
 		 * @param from
 		 *            The start node.
@@ -573,13 +573,13 @@ public String toString() {
 	public static class Node {
 
 		/**
-		 * The index of this node. You can think of this as an unique name of
-		 * the node. Automatically assigned.
+		 * The index of this node. You can think of this as an unique name of the node.
+		 * Automatically assigned.
 		 */
 		public final int index;
 		/**
-		 * The name of the node. Use this if you need to give names to your
-		 * nodes. This is used by the toString method, if present.
+		 * The name of the node. Use this if you need to give names to your nodes. This
+		 * is used by the toString method, if present.
 		 */
 		public String name = null;
 
@@ -589,9 +589,9 @@ public String toString() {
 		}
 
 		/**
-		 * Constructor. Assigns an available index to the node and adds it to
-		 * the DTMC it belongs to. You should probably use {@link DTMC#addNode()
-		 * DTMC.addNode} instead.
+		 * Constructor. Assigns an available index to the node and adds it to the DTMC
+		 * it belongs to. You should probably use {@link DTMC#addNode() DTMC.addNode}
+		 * instead.
 		 */
 		public Node() {
 			if (freeNodeNames.isEmpty()) {

src/main/java/de/uni_stuttgart/beehts/model/construction/SREParser.java

@@ -1,9 +1,9 @@
 package de.uni_stuttgart.beehts.model.construction;
 
-import java.util.ArrayList;
 import java.util.InputMismatchException;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import de.uni_stuttgart.beehts.model.SRE;
 import de.uni_stuttgart.beehts.model.Tuple;
@@ -68,11 +68,11 @@ public static SRE parse(String s) {
 	}
 
 	private static List<Token> tokenize(String s) {
-		List<String> tokens = splitAtTokens(s);
-		tokens.replaceAll(x -> x.trim());
-		List<Token> list = new ArrayList<>(tokens.size());
-		tokens.stream().filter(x -> !x.isEmpty()).forEach(x -> list.add(stringToToken(x)));
-		return list;
+		return splitAtTokens(s).stream()
+				.map(x -> x.trim())
+				.filter(x -> !x.isEmpty())
+				.map(x -> stringToToken(x))
+				.collect(Collectors.toList());
 	}
 
 	private static SRE buildSRE(List<Token> tokens) {
@@ -130,12 +130,13 @@ private static SRE buildSRE(List<Token> tokens, int firstIdx, int lastIdx) {
 				break;
 			}
 			case IDENTIFIER: {
+				String content = tokens.get(i).content;
 				if (lookingForDelimiter) {
-					throw new InputMismatchException(
-							"Was looking for a delimiter, got an identifier: " + tokens.get(i).content);
+					throw new InputMismatchException("Was looking for a delimiter, got an identifier: " + content);
 				}
+				content = applyEscapeSequences(content);
 				int rate = getRate(tokens, i + 1);
-				sres.add(new Tuple<>(SREBuilder.atomic(tokens.get(i).content), rate));
+				sres.add(new Tuple<>(SREBuilder.atomic(content), rate));
 				if (rate >= 0)
 					i += 3;
 				lookingForDelimiter = true;
@@ -220,6 +221,46 @@ else if (tokens.get(ratePosition).type != Token.Type.RATE)
 		}
 	}
 
+	/**
+	 * Apply the escape sequences supported by the parser.
+	 * 
+	 * Supported escape sequences (note that \ is escaped as neccessary in java
+	 * string literals):<br>
+	 * {@code "" == applyEscapeSequences("\\e")}<br>
+	 * {@code " " == applyEscapeSequences("\\s")}<br>
+	 * For other characters after '\', the character itself is placed there:<br>
+	 * {@code "\\" == applyEscapeSequences("\\\\")}<br>
+	 * {@code "x" == applyEscapeSequences("\\x")}
+	 * 
+	 * @param content
+	 *            The string with the escape sequences.
+	 * @return The same string with the escape sequences replaced by literals.
+	 */
+	private static String applyEscapeSequences(String content) {
+		StringBuilder sb = new StringBuilder();
+		for (int i = 0; i < content.length(); i++) {
+			if (content.charAt(i) == '\\') {
+				i++;
+				if (i >= content.length()) {
+					throw new IllegalArgumentException();
+				}
+				switch (content.charAt(i)) {
+				case 'e':
+					break; // empty string - ignore.
+				case 's':
+					sb.append(' ');
+					break;
+				default:
+					sb.append(content.charAt(i));
+					break;
+				}
+			} else {
+				sb.append(content.charAt(i));
+			}
+		}
+		return sb.toString();
+	}
+
 	private static int getRate(List<Token> tokens, int i) {
 		if (i + 2 < tokens.size() && tokens.get(i).type == Token.Type.BRACKET_OPEN
 				&& tokens.get(i + 1).type == Token.Type.RATE && tokens.get(i + 2).type == Token.Type.BRACKET_CLOSE) {
@@ -251,7 +292,7 @@ private static Token stringToToken(String x) {
 		default:
 			if (x.matches("\\d+(\\.\\d+)?")) {
 				return new Token(Token.Type.RATE, x);
-			} else if (x.matches("[A-Za-z_\\\\]\\w*")) {
+			} else if (x.matches("(\\\\[A-Za-z0-9]|(\\w|\\\\.)+)")) {
 				return new Token(Token.Type.IDENTIFIER, x);
 			} else {
 				throw new InputMismatchException("Could not parse the following string: " + x);
@@ -277,6 +318,10 @@ private static List<String> splitAtTokens(String s) {
 				tokens.add(s.charAt(i) + "");
 				lastIndex = i + 1;
 				break;
+			case '\\':
+				// escape sequence incoming, using next character as literal.
+				i++;
+				// treat this as normal text, therefore fallthrough
 			default:
 				break;
 			}

src/test/java/de/uni_stuttgart/beehts/TestModels.java

@@ -1,6 +1,7 @@
 package de.uni_stuttgart.beehts;
 
 import org.junit.Test;
+import static org.junit.Assert.*;
 
 import de.uni_stuttgart.beehts.model.DTMC;
 import de.uni_stuttgart.beehts.model.DTMCDelta;
@@ -15,6 +16,14 @@ public class TestModels {
 	@Test
 	public void parseSRE() {
 		SREBuilder.parse("((a:b)*0.2)[1]+c[2]");
+		assertEquals(SREBuilder.parse("\\e").toString(), "");
+		assertEquals(SREBuilder.parse("\\s").toString(), " ");
+		char[] chars = ":.,;-_#'+*~\\}][{?=)(/&%$§\"!^°<>|".toCharArray();
+		for (char c : chars) {
+			assertEquals(SREBuilder.parse("\\" + c).toString(), String.valueOf(c));
+		}
+		SREBuilder.parse("\\e[1] + ((a:\\::b)*0.2)[1]+\\1[2]");
+
 	}
 
 	@Test
@@ -25,12 +34,12 @@ public void parseDTMC() {
 
 		// second syntax type
 		DTMCParser.parse("0 \n 1 2 \n");
-		DTMCParser.parse("0 \n 1 2 \n 0 1 0.23 a \n 0 2 0.77 b \n 1 2 1 c");
+		DTMCParser.parse("0 \n 2 \n 0 1 0.23 a \n 0 2 0.77 b \n 1 2 1 c");
 	}
 
 	@Test
 	public void applyDelta() {
-		DTMC dtmc = DTMCParser.parse("0 \n 1 2 \n 0 1 0.23 a \n 0 2 0.77 b \n 1 2 1 c");
+		DTMC dtmc = DTMCParser.parse("0 \n 2 \n 0 1 0.23 a \n 0 2 0.77 b \n 1 2 1 c");
 		Delta<DTMC> deltaDTMC = DTMCDelta.parse("0 2 b > 0 2 0.5 b\n+0 0 0.27 d", dtmc);
 		dtmc = deltaDTMC.applyChanges(dtmc);