v 0.3.0 (#7)

.github/workflows/dart.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
 
     container:
-      image:  google/dart:latest
+      image:  dart:stable
 
     steps:
       - uses: actions/checkout@v2

CHANGELOG.md

@@ -4,6 +4,14 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.3.0] - 2022-05-09
+### Added
+- Basic support of nested lists
+
+### Changed
+- Bumped markdown dependency to 5.0.0
+- Renamed Printable to Renderable
+
 ## [0.2.3] - 2021-12-28
 ### Added
 - Optional configurable line break sequence
@@ -57,6 +65,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - Initial library version
 
+[0.3.0]: https://github.com/f3ath/marker/compare/0.2.3...0.3.0
 [0.2.3]: https://github.com/f3ath/marker/compare/0.2.2...0.2.3
 [0.2.2]: https://github.com/f3ath/marker/compare/0.2.1...0.2.2
 [0.2.1]: https://github.com/f3ath/marker/compare/0.2.0...0.2.1

lib/marker.dart

@@ -19,7 +19,7 @@ String render(Iterable<md.Node> nodes,
   for (final node in nodes) {
     node.accept(builder);
   }
-  return (builder.root.print(context) +
+  return (builder.root.render(context) +
           context.references.join(context.lineBreak))
       .trim();
 }

lib/src/ast/node.dart

@@ -1,20 +1,20 @@
 import 'package:marker/src/ast/context.dart';
-import 'package:marker/src/ast/printable.dart';
+import 'package:marker/src/ast/renderable.dart';
 import 'package:marker/src/ast/text.dart';
 
 /// The base rendering tree node.
-class Node implements Printable {
+class Node implements Renderable {
   /// Node's children
-  final List<Printable> children = [];
+  final List<Renderable> children = [];
 
   /// Attributes are copied from the corresponding parsed tree
   /// during tree building.
   final Map<String, String> attributes = {};
 
   /// Renders all children and returns concatenated output.
   @override
-  String print(Context context) =>
-      children.map((node) => node.print(context)).join();
+  String render(Context context) =>
+      children.map((node) => node.render(context)).join();
 
   /// Adds a child text node
   void addText(String text) {

lib/src/ast/printable.dart → lib/src/ast/renderable.dart

@@ -1,7 +1,7 @@
 import 'package:marker/src/ast/context.dart';
 
 /// The base interface for the rendering tree nodes.
-abstract class Printable {
+abstract class Renderable {
   /// Renders the node into markdown according to [context].
-  String print(Context context);
+  String render(Context context);
 }

lib/src/ast/text.dart

@@ -1,15 +1,15 @@
 import 'package:marker/src/ast/context.dart';
-import 'package:marker/src/ast/printable.dart';
+import 'package:marker/src/ast/renderable.dart';
 
-class Text implements Printable {
+class Text implements Renderable {
   Text(this.text);
 
   final String text;
 
   /// Escapes common markdown special characters if those could be
   /// misinterpreted.
   @override
-  String print(Context context) => text
+  String render(Context context) => text
       // dot after a number in the beginning of the string is a list item
       .replaceAllMapped(RegExp(r'^(\d+)\. '), (m) => '${m[1]}\\. ')
       // Special markdown chars: emphasis, strikethrough, table cell, links

lib/src/flavors/changelog.dart

@@ -1,27 +1,28 @@
 import 'package:marker/ast.dart';
-import 'package:marker/src/ast/printable.dart';
+import 'package:marker/src/ast/renderable.dart';
 import 'package:marker/src/flavors/original.dart';
 
 /// Changelog uses a special kind of implicit links inside H2
 class Release extends Node {
   @override
-  String print(Context context) =>
+  String render(Context context) =>
       '## ' +
       children
-          .map((node) => node is Link ? _ReleaseLink(node) : node)
-          .map((node) => node.print(context))
+          .map((node) => node is Link ? _Link(node) : node)
+          .map((node) => node.render(context))
           .join() +
       context.lineBreak;
 }
 
-class _ReleaseLink implements Printable {
-  _ReleaseLink(this._link);
+class _Link implements Renderable {
+  _Link(this._link);
 
   final Link _link;
 
   @override
-  String print(Context context) {
-    final innerText = '[${_link.children.map((e) => e.print(context)).join()}]';
+  String render(Context context) {
+    final innerText =
+        '[${_link.children.map((e) => e.render(context)).join()}]';
     var href = _link.attributes['href']!;
     final title = _link.attributes['title'];
     if (title != null) href += ' "$title"';

lib/src/flavors/original.dart

@@ -1,3 +1,5 @@
+import 'dart:convert';
+
 import 'package:marker/ast.dart';
 
 /// This is an implementation of the original markdown
@@ -8,82 +10,105 @@ class Header extends Node {
   final int level;
 
   @override
-  String print(Context context) =>
-      '#' * level + ' ${super.print(context)}' + context.lineBreak;
+  String render(Context context) =>
+      '#' * level + ' ${super.render(context)}' + context.lineBreak;
 }
 
 class Paragraph extends Node {
   @override
-  String print(Context context) => super.print(context) + context.lineBreak * 2;
+  String render(Context context) =>
+      super.render(context) + context.lineBreak * 2;
 }
 
 class LineBreak extends Node {
   @override
-  String print(Context context) => '  ' + context.lineBreak;
+  String render(Context context) => '  ' + context.lineBreak;
 }
 
 class BlockQuote extends Node {
   @override
-  String print(Context context) =>
+  String render(Context context) =>
       super
-          .print(context)
+          .render(context)
           .trim()
-          .split(context.lineBreak)
-          .map((line) => ('> ' + line).trim())
-          .join(context.lineBreak) +
+          .addLinePrefix('> ', context.lineBreak, trim: true) +
       context.lineBreak * 2;
 }
 
 class UnorderedList extends Node {
   @override
-  String print(Context context) =>
-      children.map((node) => '- ${node.print(context)}').join() +
+  String render(Context context) =>
+      children.map((node) => '- ${node.render(context)}').join() +
       context.lineBreak;
 }
 
 class OrderedList extends Node {
   @override
-  String print(Context context) =>
+  String render(Context context) =>
       children
           .asMap()
           .entries
-          .map((e) => '${e.key + 1}. ${e.value.print(context)}')
+          .map((e) => '${e.key + 1}. ${e.value.render(context)}')
           .join() +
       context.lineBreak;
 }
 
 class ListItem extends Node {
   @override
-  String print(Context context) {
-    if (children.isNotEmpty && _isBlock(children.first)) {
-      return children
-              .map((node) {
-                if (node is BlockQuote) {
-                  return '    ' +
-                      node
-                          .print(context)
-                          .split(context.lineBreak)
-                          .join(context.lineBreak + '    ');
-                }
-                if (node is Pre) {
-                  // A code block in a list gets 3 spaces
-                  // despite the standard requiring 4.
-                  // @see https://daringfireball.net/projects/markdown/syntax#list
-                  // So we have to compensate here.
-                  return ' ' * 3 +
-                      node
-                          .print(context)
-                          .split(context.lineBreak)
-                          .join(context.lineBreak + ' ' * 3);
-                }
-                return ' ' * 4 + node.print(context).trim();
-              })
-              .join(context.lineBreak * 2)
-              .trim() +
-          context.lineBreak * 2;
+  String render(Context context) {
+    if (children.isNotEmpty) {
+      if (_isBlock(children.first)) {
+        return _renderBlockChildren(context);
+      }
     }
-    return super.print(context) + context.lineBreak;
+    return children
+            .map((node) {
+              if (node is OrderedList || node is UnorderedList) {
+                // We have a sublist. It must be separated from the previous
+                // text node and from other block elements.
+                final indent = (node is UnorderedList) ? 2 : 4;
+                return context.lineBreak +
+                    node
+                        .render(context)
+                        .addLinePrefix(' ' * indent, context.lineBreak) +
+                    context.lineBreak;
+              }
+              return node.render(context);
+            })
+            .join()
+            .trim() +
+        context.lineBreak;
   }
+
+  String _renderBlockChildren(Context context) =>
+      children
+          .map((node) {
+            if (node is BlockQuote) {
+              return node
+                  .render(context)
+                  .addLinePrefix(' ' * 4, context.lineBreak);
+            }
+            if (node is Pre) {
+              // A code block in a list gets 3 spaces
+              // despite the standard requiring 4.
+              // @see https://daringfireball.net/projects/markdown/syntax#list
+              // So we have to compensate here.
+              return node
+                  .render(context)
+                  .addLinePrefix(' ' * 3, context.lineBreak);
+            }
+            return ' ' * 4 + node.render(context).trim();
+          })
+          .join(context.lineBreak * 2)
+          .trim() +
+      context.lineBreak * 2;
+
+  bool _isBlock(node) =>
+      node is Header ||
+      node is Paragraph ||
+      node is BlockQuote ||
+      node is OrderedList ||
+      node is UnorderedList;
 }
 
 class Pre extends Node {}
@@ -92,26 +117,30 @@ class Code extends Node {
   final _buf = StringBuffer();
 
   @override
-  String print(Context context) {
+  String render(Context context) {
     final text = _buf.toString();
     if (text.contains(context.lineBreak)) {
-      return ' ' * 4 +
-          text.split(context.lineBreak).join(context.lineBreak + ' ' * 4);
+      return text.addLinePrefix(' ' * 4, context.lineBreak);
     }
-    var fencing = 1;
-    while (text.contains('`' * fencing)) {
-      fencing++;
-    } // Figure out the fencing length
-    return '`' * fencing + text + '`' * fencing;
+    final fencing = _detectFencing(text);
+    return fencing + text + fencing;
   }
 
   @override
   void addText(String text) => _buf.write(text);
+
+  String _detectFencing(String text) {
+    var fencing = '';
+    do {
+      fencing += '`';
+    } while (text.contains(fencing));
+    return fencing;
+  }
 }
 
 class HorizontalRule extends Node {
   @override
-  String print(Context context) => '---' + context.lineBreak;
+  String render(Context context) => '---' + context.lineBreak;
 }
 
 class Emphasis extends Node {
@@ -120,13 +149,13 @@ class Emphasis extends Node {
   final String mark;
 
   @override
-  String print(Context context) => '$mark${super.print(context)}$mark';
+  String render(Context context) => '$mark${super.render(context)}$mark';
 }
 
 class Link extends Node {
   @override
-  String print(Context context) {
-    final innerText = '[${super.print(context)}]';
+  String render(Context context) {
+    final innerText = '[${super.render(context)}]';
     var href = attributes['href']!;
     if (attributes.containsKey('title')) {
       href += ' "${attributes['title']}"';
@@ -143,7 +172,7 @@ class Link extends Node {
 
 class Image extends Node {
   @override
-  String print(Context context) {
+  String render(Context context) {
     var src = attributes['src']!;
     if (attributes.containsKey('title')) {
       src += ' "${attributes['title']}"';
@@ -160,9 +189,14 @@ class Image extends Node {
 
 int _id = 1; // id generator for images and links
 
-bool _isBlock(node) =>
-    node is Header ||
-    node is Paragraph ||
-    node is BlockQuote ||
-    node is OrderedList ||
-    node is UnorderedList;
+extension _StringExt on String {
+  static const _splitter = LineSplitter();
+
+  /// Adds [prefix] to all lines in the string.
+  addLinePrefix(String prefix, String lineBreak, {bool trim = false}) =>
+      _splitter
+          .convert(this)
+          .map((_) => prefix + _)
+          .map((_) => trim ? _.trim() : _)
+          .join(lineBreak);
+}

pubspec.yaml

@@ -1,6 +1,6 @@
 name: marker
 description: A renderer (printer) for the markdown library. Renders the parsed AST back into markdown.
-version: 0.2.3
+version: 0.3.0
 homepage: https://github.com/f3ath/marker
 
 cider:
@@ -9,14 +9,13 @@ cider:
     diff: https://github.com/f3ath/marker/compare/%from%...%to%
 
 environment:
-  sdk: '>=2.15.1 <3.0.0'
+  sdk: '>=2.16.2 <3.0.0'
 
 dependencies:
-  markdown: ^4.0.0
+  markdown: ^5.0.0
 
 dev_dependencies:
   test: ^1.16.0
   lints: ^1.0.1
   coverage: ^1.0.1
   check_coverage: ^0.0.1
-  cider: ^0.1.1