Improve error handling in EventOccurrenceGrammar parsing methods

This commit enhances the error handling in the EventOccurrenceGrammar class by adding specific catch blocks for expected parse exceptions. Each parsing method now gracefully returns null or false when encountering a known parse exception, while still handling unexpected exceptions to ensure the parsing process continues smoothly. This change improves the robustness and clarity of the parsing logic.

Core/Parsers/EventOccurrenceGrammar.cs

@@ -112,8 +112,14 @@ public static class EventOccurrenceGrammar
             var result = SectionHeader.Parse(line);
             return result;
         }
+        catch (Sprache.ParseException)
+        {
+            // Expected - line is not a section header, return null
+            return null;
+        }
         catch
         {
+            // Unexpected exception, return null to continue parsing
             return null;
         }
     }
@@ -129,8 +135,14 @@ public static class EventOccurrenceGrammar
             GeneralSchedule.Parse(line);
             return true;
         }
+        catch (Sprache.ParseException)
+        {
+            // Expected - line is not a General Schedule header
+            return false;
+        }
         catch
         {
+            // Unexpected exception, return false to continue parsing
             return false;
         }
     }
@@ -184,8 +196,14 @@ public static class EventOccurrenceGrammar
             var parsed = result.Parse(restOfLine);
             return parsed;
         }
+        catch (Sprache.ParseException)
+        {
+            // Expected - line is not a valid occurrence line, return null
+            return null;
+        }
         catch
         {
+            // Unexpected exception, return null to continue parsing
             return null;
         }
     }