some bug fixes and relaxation in the grammar

src/main/antlr4/edu/kit/formal/proofscriptparser/ScriptLanguage.g4

@@ -86,8 +86,8 @@ casesStmt
     ;
 
 casesList
-    :   CASE expression COLON INDENT stmtList DEDENT casesList*
-    |   DEFAULT  COLON INDENT stmtList DEDENT
+    :   CASE expression COLON? INDENT stmtList DEDENT casesList*
+    |   DEFAULT  COLON? INDENT stmtList DEDENT
     ;
 
 forEachStmt
@@ -99,7 +99,7 @@ theOnlyStmt
     ;
 
 scriptCommand
-    :   ID (ID '=' expression)* SEMICOLON
+    :   ID ((ID '=')? expression)* SEMICOLON
     ;
 
 callStmt

src/main/java/edu/kit/formatl/proofscriptparser/ast/Literal.java

@@ -2,7 +2,6 @@ package edu.kit.formatl.proofscriptparser.ast;
 
 import org.antlr.v4.runtime.ParserRuleContext;
 import org.antlr.v4.runtime.Token;
-import org.graalvm.compiler.nodes.calc.IntegerDivRemNode;
 
 import java.util.Optional;
 
@@ -11,7 +10,7 @@ import java.util.Optional;
  * @version 1 (28.04.17)
  */
 public abstract class Literal extends ASTNode<ParserRuleContext> {
-    protected Optional<Token> token;
+    Optional<Token> token;
 
     public Optional<Token> getToken() {
         return token;

src/main/java/edu/kit/formatl/proofscriptparser/ast/MatchExpression.java

 package edu.kit.formatl.proofscriptparser.ast;
 
 import edu.kit.formal.proofscriptparser.ScriptLanguageParser;
-import org.graalvm.compiler.core.match.MatchPattern;
 
 import java.util.Map;
 

src/test/resources/edu/kit/formal/proofscriptparser/scripts/fullcases.txt

+script fc() {
+    cases {
+        case x = y {
+            print a;
+        }
+
+        default {
+            print `blubb`;
+        }
+    }
+}
\ No newline at end of file

src/test/resources/edu/kit/formal/proofscriptparser/scripts/justarithmetic.txt

+script justArithm(x:int, y:int) {
+  z : int := x + y;
+}
\ No newline at end of file