introduce a Line class

CHANGELOG.md

@@ -6,13 +6,19 @@
   `indicatorForCheckedCheckBox`, and `indicatorForUncheckedCheckBox`.
 * **Breaking change**: Removed `BlockHtmlSyntax`, `BlockTagBlockHtmlSyntax`,
   `LongBlockHtmlSyntax`, and `OtherTagBlockHtmlSyntax`.
+* **Breaking change**: Change the `line` properties of type `String` to `Line`.
+* **Breaking change**: Change the `lines` properties of type `List<String>` to
+  `List<Line>`.
 * Add a new syntax `HtmlBlockSyntax` to parse HTML blocks.
 * Add a new syntax `DecodeHtmlSyntax` to decode HTML entity and numeric
   character references.
 * Add a new syntax `SoftLineBreakSyntax` to remove the single space before the
   line ending.
 * Add a new syntax `EscapeHtmlSyntax` to encode (`"`), (`<`), (`>`) and (`&`).
 * Add an option `caseSensitive` to `TextSyntax`.
+* Add a new public method `parse(String text)` for `Document`.
+* Add a new public method `parseLineList(List<Line> text)` for `Document`.
+* Add a new type: `Line`.
 
 ## 6.0.1
 

lib/markdown.dart

@@ -82,5 +82,6 @@ export 'src/inline_syntaxes/link_syntax.dart';
 export 'src/inline_syntaxes/soft_line_break_syntax.dart';
 export 'src/inline_syntaxes/strikethrough_syntax.dart';
 export 'src/inline_syntaxes/text_syntax.dart';
+export 'src/line.dart';
 
 const version = packageVersion;

lib/src/block_parser.dart

@@ -16,11 +16,12 @@ import 'block_syntaxes/paragraph_syntax.dart';
 import 'block_syntaxes/setext_header_syntax.dart';
 import 'block_syntaxes/unordered_list_syntax.dart';
 import 'document.dart';
+import 'line.dart';
 
 /// Maintains the internal state needed to parse a series of lines into blocks
 /// of Markdown suitable for further inline parsing.
 class BlockParser {
-  final List<String> lines;
+  final List<Line> lines;
 
   /// The Markdown document this parser is parsing.
   final Document document;
@@ -63,10 +64,10 @@ class BlockParser {
   }
 
   /// Gets the current line.
-  String get current => lines[_pos];
+  Line get current => lines[_pos];
 
   /// Gets the line after the current one or `null` if there is none.
-  String? get next {
+  Line? get next {
     // Don't read past the end.
     if (_pos >= lines.length - 1) return null;
     return lines[_pos + 1];
@@ -78,7 +79,7 @@ class BlockParser {
   /// `peek(0)` is equivalent to [current].
   ///
   /// `peek(1)` is equivalent to [next].
-  String? peek(int linesAhead) {
+  Line? peek(int linesAhead) {
     if (linesAhead < 0) {
       throw ArgumentError('Invalid linesAhead: $linesAhead; must be >= 0.');
     }
@@ -100,13 +101,13 @@ class BlockParser {
   /// Gets whether or not the current line matches the given pattern.
   bool matches(RegExp regex) {
     if (isDone) return false;
-    return regex.hasMatch(current);
+    return regex.hasMatch(current.content);
   }
 
   /// Gets whether or not the next line matches the given pattern.
   bool matchesNext(RegExp regex) {
     if (next == null) return false;
-    return regex.hasMatch(next!);
+    return regex.hasMatch(next!.content);
   }
 
   List<Node> parseLines() {

lib/src/block_syntaxes/block_syntax.dart

@@ -4,6 +4,7 @@
 
 import '../ast.dart';
 import '../block_parser.dart';
+import '../line.dart';
 
 abstract class BlockSyntax {
   const BlockSyntax();
@@ -14,19 +15,19 @@ abstract class BlockSyntax {
   bool canEndBlock(BlockParser parser) => true;
 
   bool canParse(BlockParser parser) {
-    return pattern.hasMatch(parser.current);
+    return pattern.hasMatch(parser.current.content);
   }
 
   Node? parse(BlockParser parser);
 
-  List<String?> parseChildLines(BlockParser parser) {
+  List<Line?> parseChildLines(BlockParser parser) {
     // Grab all of the lines that form the block element.
-    final childLines = <String?>[];
+    final childLines = <Line?>[];
 
     while (!parser.isDone) {
-      final match = pattern.firstMatch(parser.current);
+      final match = pattern.firstMatch(parser.current.content);
       if (match == null) break;
-      childLines.add(match[1]);
+      childLines.add(parser.current);
       parser.advance();
     }
 

lib/src/block_syntaxes/blockquote_syntax.dart

@@ -5,6 +5,7 @@
 import '../ast.dart';
 import '../block_parser.dart';
 import '../charcode.dart';
+import '../line.dart';
 import '../patterns.dart';
 import '../util.dart';
 import 'block_syntax.dart';
@@ -19,32 +20,32 @@ class BlockquoteSyntax extends BlockSyntax {
   const BlockquoteSyntax();
 
   @override
-  List<String> parseChildLines(BlockParser parser) {
+  List<Line> parseChildLines(BlockParser parser) {
     // Grab all of the lines that form the blockquote, stripping off the ">".
-    final childLines = <String>[];
+    final childLines = <Line>[];
 
     while (!parser.isDone) {
       final currentLine = parser.current;
-      final match = pattern.firstMatch(parser.current);
+      final match = pattern.firstMatch(parser.current.content);
       if (match != null) {
         // A block quote marker consists of a `>` together with an optional
         // following space of indentation, see
         // https://spec.commonmark.org/0.30/#block-quote-marker.
         final markerStart = match.match.indexOf('>');
         int markerEnd;
-        if (currentLine.length > 1) {
+        if (currentLine.content.length > 1) {
           var hasSpace = false;
           // Check if there is a following space if the marker is not at the end
           // of this line.
-          if (markerStart < currentLine.length - 1) {
-            final nextChar = currentLine.codeUnitAt(markerStart + 1);
+          if (markerStart < currentLine.content.length - 1) {
+            final nextChar = currentLine.content.codeUnitAt(markerStart + 1);
             hasSpace = nextChar == $tab || nextChar == $space;
           }
           markerEnd = markerStart + (hasSpace ? 2 : 1);
         } else {
           markerEnd = markerStart + 1;
         }
-        childLines.add(currentLine.substring(markerEnd));
+        childLines.add(Line(currentLine.content.substring(markerEnd)));
         parser.advance();
         continue;
       }
@@ -59,10 +60,10 @@ class BlockquoteSyntax extends BlockSyntax {
       final otherMatched =
           parser.blockSyntaxes.firstWhere((s) => s.canParse(parser));
       if ((otherMatched is ParagraphSyntax &&
-              lastLine.isNotEmpty &&
-              !codeFencePattern.hasMatch(lastLine)) ||
+              !lastLine.isBlankLine &&
+              !codeFencePattern.hasMatch(lastLine.content)) ||
           (otherMatched is CodeBlockSyntax &&
-              !indentPattern.hasMatch(lastLine))) {
+              !indentPattern.hasMatch(lastLine.content))) {
         childLines.add(parser.current);
         parser.advance();
       } else {

lib/src/block_syntaxes/code_block_syntax.dart

@@ -4,6 +4,7 @@
 
 import '../ast.dart';
 import '../block_parser.dart';
+import '../line.dart';
 import '../patterns.dart';
 import '../util.dart';
 import 'block_syntax.dart';
@@ -19,21 +20,21 @@ class CodeBlockSyntax extends BlockSyntax {
   const CodeBlockSyntax();
 
   @override
-  List<String?> parseChildLines(BlockParser parser) {
-    final childLines = <String?>[];
+  List<Line> parseChildLines(BlockParser parser) {
+    final childLines = <Line>[];
 
     while (!parser.isDone) {
-      final isBlankLine = parser.current.isBlank;
+      final isBlankLine = parser.current.isBlankLine;
       if (isBlankLine && _shouldEnd(parser)) {
         break;
       }
 
       if (!isBlankLine &&
           childLines.isNotEmpty &&
-          pattern.hasMatch(parser.current) != true) {
+          pattern.hasMatch(parser.current.content) != true) {
         break;
       }
-      childLines.add(parser.current.dedent().text);
+      childLines.add(Line(parser.current.content.dedent().text));
 
       parser.advance();
     }
@@ -46,9 +47,9 @@ class CodeBlockSyntax extends BlockSyntax {
     final childLines = parseChildLines(parser);
 
     // The Markdown tests expect a trailing newline.
-    childLines.add('');
+    childLines.add(Line(''));
 
-    var content = childLines.join('\n');
+    var content = childLines.map((e) => e.content).join('\n');
     if (parser.document.encodeHtml) {
       content = escapeHtml(content);
     }
@@ -67,12 +68,12 @@ class CodeBlockSyntax extends BlockSyntax {
 
       // It does not matter how many blank lines between chunks:
       // https://spec.commonmark.org/0.30/#example-111
-      if (nextLine.isBlank) {
+      if (nextLine.isBlankLine) {
         i++;
         continue;
       }
 
-      return pattern.hasMatch(nextLine) == false;
+      return pattern.hasMatch(nextLine.content) == false;
     }
   }
 }

lib/src/block_syntaxes/dummy_block_syntax.dart

@@ -27,7 +27,7 @@ class DummyBlockSyntax extends BlockSyntax {
     final childLines = <String>[];
 
     while (!BlockSyntax.isAtBlockEnd(parser)) {
-      childLines.add(parser.current);
+      childLines.add(parser.current.content);
       parser.advance();
     }
 

lib/src/block_syntaxes/fenced_blockquote_syntax.dart

@@ -4,6 +4,7 @@
 
 import '../ast.dart';
 import '../block_parser.dart';
+import '../line.dart';
 import '../patterns.dart';
 import 'block_syntax.dart';
 
@@ -15,12 +16,12 @@ class FencedBlockquoteSyntax extends BlockSyntax {
   RegExp get pattern => blockquoteFencePattern;
 
   @override
-  List<String> parseChildLines(BlockParser parser) {
-    final childLines = <String>[];
+  List<Line> parseChildLines(BlockParser parser) {
+    final childLines = <Line>[];
     parser.advance();
 
     while (!parser.isDone) {
-      final match = pattern.hasMatch(parser.current);
+      final match = pattern.hasMatch(parser.current.content);
       if (!match) {
         childLines.add(parser.current);
         parser.advance();

lib/src/block_syntaxes/fenced_code_block_syntax.dart

@@ -4,6 +4,7 @@
 
 import '../ast.dart';
 import '../block_parser.dart';
+import '../line.dart';
 import '../patterns.dart';
 import '../util.dart';
 import 'block_syntax.dart';
@@ -20,14 +21,14 @@ class FencedCodeBlockSyntax extends BlockSyntax {
   @override
   Node parse(BlockParser parser) {
     final openingFence = _FenceMatch.fromMatch(pattern.firstMatch(
-      escapePunctuation(parser.current),
+      escapePunctuation(parser.current.content),
     )!);
 
     var text = parseChildLines(
       parser,
       openingFence.marker,
       openingFence.indent,
-    ).join('\n');
+    ).map((e) => e.content).join('\n');
 
     if (parser.document.encodeHtml) {
       text = escapeHtml(text);
@@ -54,26 +55,28 @@ class FencedCodeBlockSyntax extends BlockSyntax {
   }
 
   @override
-  List<String> parseChildLines(
+  List<Line> parseChildLines(
     BlockParser parser, [
     String openingMarker = '',
     int indent = 0,
   ]) {
-    final childLines = <String>[];
+    final childLines = <Line>[];
 
     parser.advance();
 
     _FenceMatch? closingFence;
     while (!parser.isDone) {
-      final match = pattern.firstMatch(parser.current);
+      final match = pattern.firstMatch(parser.current.content);
       closingFence = match == null ? null : _FenceMatch.fromMatch(match);
 
       // Closing code fences cannot have info strings:
       // https://spec.commonmark.org/0.30/#example-147
       if (closingFence == null ||
           !closingFence.marker.startsWith(openingMarker) ||
           closingFence.hasInfo) {
-        childLines.add(_removeIndentation(parser.current, indent));
+        childLines.add(
+          Line(_removeIndentation(parser.current.content, indent)),
+        );
         parser.advance();
       } else {
         parser.advance();
@@ -85,7 +88,7 @@ class FencedCodeBlockSyntax extends BlockSyntax {
     // https://spec.commonmark.org/0.30/#example-128
     if (closingFence == null &&
         childLines.isNotEmpty &&
-        childLines.last.trim().isEmpty) {
+        childLines.last.isBlankLine) {
       childLines.removeLast();
     }
 

lib/src/block_syntaxes/header_syntax.dart

@@ -16,7 +16,7 @@ class HeaderSyntax extends BlockSyntax {
 
   @override
   Node parse(BlockParser parser) {
-    final match = pattern.firstMatch(parser.current)!;
+    final match = pattern.firstMatch(parser.current.content)!;
     final matchedText = match[0]!;
     final openMarker = match[1]!;
     final closeMarker = match[2];
@@ -26,10 +26,13 @@ class HeaderSyntax extends BlockSyntax {
 
     String? content;
     if (closeMarker == null) {
-      content = parser.current.substring(openMarkerEnd);
+      content = parser.current.content.substring(openMarkerEnd);
     } else {
       final closeMarkerStart = matchedText.lastIndexOf(closeMarker);
-      content = parser.current.substring(openMarkerEnd, closeMarkerStart);
+      content = parser.current.content.substring(
+        openMarkerEnd,
+        closeMarkerStart,
+      );
     }
     content = content.trim();