Answer for https://stackoverflow.com/questions/78078779

petitparser · Mar 1, 2024 · 15dd9e0 · 15dd9e0
1 parent 249c55a
commit 15dd9e0
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Showing 3 changed files with 41 additions and 20 deletions.
diff --git a/test/parser_test.dart b/test/parser_test.dart
@@ -5,14 +5,6 @@ import 'generated/sequence_test.dart' as sequence_test;
 import 'utils/assertions.dart';
 import 'utils/matchers.dart';
 
-TypeMatcher<SeparatedList<R, S>> isSeparatedList<R, S>({
-  List<R> elements = const [],
-  List<S> separators = const [],
-}) =>
-    isA<SeparatedList<R, S>>()
-        .having((list) => list.elements, 'elements', elements)
-        .having((list) => list.separators, 'separators', separators);
-
 void main() {
   group('action', () {
     group('cast', () {
@@ -2161,24 +2153,24 @@ void main() {
         expect(
             parser,
             isParseSuccess('1a2b3',
-                result: isSeparatedList(
+                result: isSeparatedList<String, String>(
                     elements: ['1', '2', '3'], separators: ['a', 'b'])));
         expect(
             parser,
             isParseSuccess('1a2b3c',
-                result: isSeparatedList(
+                result: isSeparatedList<String, String>(
                     elements: ['1', '2', '3'], separators: ['a', 'b']),
                 position: 5));
         expect(
             parser,
             isParseSuccess('1a2b3c4',
-                result: isSeparatedList(
+                result: isSeparatedList<String, String>(
                     elements: ['1', '2', '3'], separators: ['a', 'b']),
                 position: 5));
         expect(
             parser,
             isParseSuccess('1a2b3c4d',
-                result: isSeparatedList(
+                result: isSeparatedList<String, String>(
                     elements: ['1', '2', '3'], separators: ['a', 'b']),
                 position: 5));
       });
@@ -2193,35 +2185,35 @@ void main() {
         expect(
             parser,
             isParseSuccess('1a2',
-                result:
-                    isSeparatedList(elements: ['1', '2'], separators: ['a'])));
+                result: isSeparatedList<String, String>(
+                    elements: ['1', '2'], separators: ['a'])));
         expect(
             parser,
             isParseSuccess('1a2b',
-                result:
-                    isSeparatedList(elements: ['1', '2'], separators: ['a']),
+                result: isSeparatedList<String, String>(
+                    elements: ['1', '2'], separators: ['a']),
                 position: 3));
         expect(
             parser,
             isParseSuccess('1a2b3',
-                result: isSeparatedList(
+                result: isSeparatedList<String, String>(
                     elements: ['1', '2', '3'], separators: ['a', 'b'])));
         expect(
             parser,
             isParseSuccess('1a2b3c',
-                result: isSeparatedList(
+                result: isSeparatedList<String, String>(
                     elements: ['1', '2', '3'], separators: ['a', 'b']),
                 position: 5));
         expect(
             parser,
             isParseSuccess('1a2b3c4',
-                result: isSeparatedList(
+                result: isSeparatedList<String, String>(
                     elements: ['1', '2', '3'], separators: ['a', 'b']),
                 position: 5));
         expect(
             parser,
             isParseSuccess('1a2b3c4d',
-                result: isSeparatedList(
+                result: isSeparatedList<String, String>(
                     elements: ['1', '2', '3'], separators: ['a', 'b']),
                 position: 5));
       });

diff --git a/test/regression_test.dart b/test/regression_test.dart
@@ -581,4 +581,24 @@ void main() {
       expect(parser, isParseSuccess('AAaaAA', result: 'fallback'));
     });
   });
+  group('https://stackoverflow.com/questions/78078779', () {
+    test('How to consume only as long as another parser accepts?', () {
+      final parser = digit().plusLazy(digit().repeat(3).not());
+      expect(parser, isParseSuccess('123', result: ['1'], position: 1));
+      expect(parser, isParseSuccess('1234', result: ['1', '2'], position: 2));
+    });
+    test('How to recognize a list of items with optional delimiters?', () {
+      final parser = digit().plusSeparated(char(',').optional());
+      expect(
+          parser,
+          isParseSuccess('1,2,3',
+              result: isSeparatedList<String, String?>(
+                  elements: ['1', '2', '3'], separators: [',', ','])));
+      expect(
+          parser,
+          isParseSuccess('12,3',
+              result: isSeparatedList<String, String?>(
+                  elements: ['1', '2', '3'], separators: [null, ','])));
+    });
+  });
 }
diff --git a/test/utils/matchers.dart b/test/utils/matchers.dart
@@ -140,3 +140,12 @@ Matcher isLinterIssue({
         .having((issue) => issue.parser, 'parser', parser)
         .having((issue) => issue.description, 'description', description)
         .having((issue) => issue.toString(), 'toString()', toString);
+
+/// Returns a [Matcher] that asserts a [SeparatedList].
+Matcher isSeparatedList<R, S>({
+  dynamic elements = anything,
+  dynamic separators = anything,
+}) =>
+    isA<SeparatedList<R, S>>()
+        .having((list) => list.elements, 'elements', elements)
+        .having((list) => list.separators, 'separators', separators);