add error handling: parser now throws exceptions

src/JobShopParser/jobshop2_parser.py

@@ -16,13 +16,18 @@ class JobShop2Visitor(JobShopVisitor):
 
 def parse_jobshop2_string(inputdata: str) -> JobShopProblem:
     """parse string of jobshop2-formatted data (single problem instance, no name & description)
-    and return JobShopProblem"""
+    and return JobShopProblem
+    Raises a ParseError exception on errors"""
+    try:
         parse_tree = parser.parse(inputdata)
+    except arpeggio.NoMatch as e:
+        raise ParseError("Error while parsing problem input data at line {}, col {}:\n Rules {} did not match.".format(e.line, e.col, e.rules))
     return arpeggio.visit_parse_tree(parse_tree, JobShop2Visitor())
 
 def parse_jobshop2_file(filename: Union[str, bytes]) -> JobShopProblem:
     """Open file with jobshop2-formatted data (single problem instance, no name & description),
-    parse it and return JobShopProblem"""
+    parse it and return JobShopProblem
+    Raises a ParseError exception on errors"""
 
     with open(filename) as datafile:
         inputdata: str = datafile.read()