improve grammar parsing

src/main/java/parser/grammar/Grammar.java

@@ -35,22 +35,30 @@ public class Grammar {
                      .collect(Collectors.toUnmodifiableList());
 
         try {
-            String startSymbol = lines.get(0).split(" ")[1];
+            String startSymbol = "";
-            String epsilonSymbol = lines.get(1).split(" ")[1];
+            String epsilonSymbol = "";
-
+            Set<String> terminals = new HashSet<>();
-            String[] term = lines.get(2).split(" ");
+            Set<String> nonterminals = new HashSet<>();
-            term = Arrays.copyOfRange(term, 1, term.length);
-            Set<String> terminals = new HashSet<>(Arrays.asList(term));
-
-            String[] nterm = lines.get(3).split(" ");
-            nterm = Arrays.copyOfRange(nterm, 1, nterm.length);
-            Set<String> nonterminals = new HashSet<>(Arrays.asList(nterm));
 
             Set<GrammarRule> rules = new HashSet<>();
-            for (int i = 4; i < lines.size(); i++) {
+            for (String line : lines) {
+
+                if (line.startsWith("START:")) {
+
+                    startSymbol = line.split(" ")[1];
+                } else if (line.startsWith("EPS:")) {
+
+                    epsilonSymbol = line.split(" ")[1];
+                } else if (line.startsWith("TERM:")) {
+
+                    terminals.addAll(Arrays.stream(line.split(" ")).skip(1).collect(Collectors.toSet()));
+                } else if (line.startsWith("NTERM:")) {
+
+                    nonterminals.addAll(Arrays.stream(line.split(" ")).skip(1).collect(Collectors.toSet()));
+                } else {
+
                     // "S -> E T2 | EPS" wird zu leftside = "S" und rightside = "E T2 | epsilon"
-                String[] split = lines.get(i)
+                    String[] split = line.replaceAll("EPS", epsilonSymbol)
-                                      .replaceAll("EPS", epsilonSymbol)
                                          .split("->");
 
                     String leftside = split[0].trim();
@@ -64,6 +72,7 @@ public class Grammar {
                         rules.add(rule);
                     }
                 }
+            }
 
             return new Grammar(terminals, nonterminals,
                                startSymbol, epsilonSymbol,