format/mdext: add indented paragraph fixer

format/mdext/indentableparagraph.go

@@ -0,0 +1,28 @@
+// Copyright (c) 2024 Tulir Asokan
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package mdext
+
+import (
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/util"
+)
+
+// indentableParagraphParser is the default paragraph parser with CanAcceptIndentedLine.
+// Used when disabling CodeBlockParser (as disabling it without a replacement will make indented blocks disappear).
+type indentableParagraphParser struct {
+	parser.BlockParser
+}
+
+var defaultIndentableParagraphParser = &indentableParagraphParser{BlockParser: parser.NewParagraphParser()}
+
+func (b *indentableParagraphParser) CanAcceptIndentedLine() bool {
+	return true
+}
+
+// FixIndentedParagraphs is a goldmark option which fixes indented paragraphs when disabling CodeBlockParser.
+var FixIndentedParagraphs = goldmark.WithParserOptions(parser.WithBlockParsers(util.Prioritized(defaultIndentableParagraphParser, 500)))