Made ParserError a FormatException to follow typical Dart exception s…

…tyle.

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 2.5.0
+
+* Made ParserError a FormatException to follow typical Dart exception style. 
+
 ## 2.4.0
 
 * Dart 2.4 compatibility and requirement.

petitparser/lib/src/core/contexts/exception.dart

@@ -3,11 +3,20 @@ library petitparser.core.contexts.exception;
 import 'package:petitparser/src/core/contexts/failure.dart';
 
 /// An exception raised in case of a parse error.
-class ParserException implements Exception {
+class ParserException implements FormatException {
   final Failure failure;
 
   ParserException(this.failure);
 
+  @override
+  String get message => failure.message;
+
+  @override
+  int get offset => failure.position;
+
+  @override
+  String get source => failure.buffer;
+
   @override
   String toString() => '${failure.message} at ${failure.toPositionString()}';
 }

petitparser/test/petitparser_test.dart

@@ -985,6 +985,9 @@ void main() {
         fail('Expected ParserError to be thrown');
       } on ParserException catch (error) {
         expect(error.failure, same(failure));
+        expect(error.message, 'error');
+        expect(error.offset, 0);
+        expect(error.source, buffer);
         expect(error.toString(), 'error at 1:1');
       }
       expect(failure.message, 'error');
@@ -1001,6 +1004,9 @@ void main() {
         fail('Expected ParserError to be thrown');
       } on ParserException catch (error) {
         expect(error.failure, same(failure));
+        expect(error.message, 'error');
+        expect(error.offset, 2);
+        expect(error.source, buffer);
         expect(error.toString(), 'error at 2:1');
       }
       expect(failure.message, 'error');
@@ -1019,6 +1025,9 @@ void main() {
         fail('Expected ParserError to be thrown');
       } on ParserException catch (error) {
         expect(error.failure, same(failure));
+        expect(error.message, 'error');
+        expect(error.offset, 2);
+        expect(error.source, buffer);
         expect(error.toString(), 'error at 2:1');
       }
       expect(failure.message, 'error');