[chore/bugfix] Switch markdown from blackfriday to goldmark (#1267)

Co-authored-by: Autumn! <autumnull@posteo.net>

1 files changed, 287 insertions, 0 deletions

diff --git a/vendor/github.com/yuin/goldmark/parser/list.go b/vendor/github.com/yuin/goldmark/parser/list.go
new file mode 100644
index 000000000..e5cad1173
--- /dev/null
+++ b/vendor/github.com/yuin/goldmark/parser/list.go
@@ -0,0 +1,287 @@
+package parser
+
+import (
+	"strconv"
+
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/text"
+	"github.com/yuin/goldmark/util"
+)
+
+type listItemType int
+
+const (
+	notList listItemType = iota
+	bulletList
+	orderedList
+)
+
+var skipListParserKey = NewContextKey()
+var emptyListItemWithBlankLines = NewContextKey()
+var listItemFlagValue interface{} = true
+
+// Same as
+// `^(([ ]*)([\-\*\+]))(\s+.*)?\n?$`.FindSubmatchIndex or
+// `^(([ ]*)(\d{1,9}[\.\)]))(\s+.*)?\n?$`.FindSubmatchIndex
+func parseListItem(line []byte) ([6]int, listItemType) {
+	i := 0
+	l := len(line)
+	ret := [6]int{}
+	for ; i < l && line[i] == ' '; i++ {
+		c := line[i]
+		if c == '\t' {
+			return ret, notList
+		}
+	}
+	if i > 3 {
+		return ret, notList
+	}
+	ret[0] = 0
+	ret[1] = i
+	ret[2] = i
+	var typ listItemType
+	if i < l && (line[i] == '-' || line[i] == '*' || line[i] == '+') {
+		i++
+		ret[3] = i
+		typ = bulletList
+	} else if i < l {
+		for ; i < l && util.IsNumeric(line[i]); i++ {
+		}
+		ret[3] = i
+		if ret[3] == ret[2] || ret[3]-ret[2] > 9 {
+			return ret, notList
+		}
+		if i < l && (line[i] == '.' || line[i] == ')') {
+			i++
+			ret[3] = i
+		} else {
+			return ret, notList
+		}
+		typ = orderedList
+	} else {
+		return ret, notList
+	}
+	if i < l && line[i] != '\n' {
+		w, _ := util.IndentWidth(line[i:], 0)
+		if w == 0 {
+			return ret, notList
+		}
+	}
+	if i >= l {
+		ret[4] = -1
+		ret[5] = -1
+		return ret, typ
+	}
+	ret[4] = i
+	ret[5] = len(line)
+	if line[ret[5]-1] == '\n' && line[i] != '\n' {
+		ret[5]--
+	}
+	return ret, typ
+}
+
+func matchesListItem(source []byte, strict bool) ([6]int, listItemType) {
+	m, typ := parseListItem(source)
+	if typ != notList && (!strict || strict && m[1] < 4) {
+		return m, typ
+	}
+	return m, notList
+}
+
+func calcListOffset(source []byte, match [6]int) int {
+	offset := 0
+	if match[4] < 0 || util.IsBlank(source[match[4]:]) { // list item starts with a blank line
+		offset = 1
+	} else {
+		offset, _ = util.IndentWidth(source[match[4]:], match[4])
+		if offset > 4 { // offseted codeblock
+			offset = 1
+		}
+	}
+	return offset
+}
+
+func lastOffset(node ast.Node) int {
+	lastChild := node.LastChild()
+	if lastChild != nil {
+		return lastChild.(*ast.ListItem).Offset
+	}
+	return 0
+}
+
+type listParser struct {
+}
+
+var defaultListParser = &listParser{}
+
+// NewListParser returns a new BlockParser that
+// parses lists.
+// This parser must take precedence over the ListItemParser.
+func NewListParser() BlockParser {
+	return defaultListParser
+}
+
+func (b *listParser) Trigger() []byte {
+	return []byte{'-', '+', '*', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'}
+}
+
+func (b *listParser) Open(parent ast.Node, reader text.Reader, pc Context) (ast.Node, State) {
+	last := pc.LastOpenedBlock().Node
+	if _, lok := last.(*ast.List); lok || pc.Get(skipListParserKey) != nil {
+		pc.Set(skipListParserKey, nil)
+		return nil, NoChildren
+	}
+	line, _ := reader.PeekLine()
+	match, typ := matchesListItem(line, true)
+	if typ == notList {
+		return nil, NoChildren
+	}
+	start := -1
+	if typ == orderedList {
+		number := line[match[2] : match[3]-1]
+		start, _ = strconv.Atoi(string(number))
+	}
+
+	if ast.IsParagraph(last) && last.Parent() == parent {
+		// we allow only lists starting with 1 to interrupt paragraphs.
+		if typ == orderedList && start != 1 {
+			return nil, NoChildren
+		}
+		//an empty list item cannot interrupt a paragraph:
+		if match[4] < 0 || util.IsBlank(line[match[4]:match[5]]) {
+			return nil, NoChildren
+		}
+	}
+
+	marker := line[match[3]-1]
+	node := ast.NewList(marker)
+	if start > -1 {
+		node.Start = start
+	}
+	pc.Set(emptyListItemWithBlankLines, nil)
+	return node, HasChildren
+}
+
+func (b *listParser) Continue(node ast.Node, reader text.Reader, pc Context) State {
+	list := node.(*ast.List)
+	line, _ := reader.PeekLine()
+	if util.IsBlank(line) {
+		if node.LastChild().ChildCount() == 0 {
+			pc.Set(emptyListItemWithBlankLines, listItemFlagValue)
+		}
+		return Continue | HasChildren
+	}
+
+	// "offset" means a width that bar indicates.
+	//    -  aaaaaaaa
+	// |----|
+	//
+	// If the indent is less than the last offset like
+	// - a
+	//  - b          <--- current line
+	// it maybe a new child of the list.
+	//
+	// Empty list items can have multiple blanklines
+	//
+	// -             <--- 1st item is an empty thus "offset" is unknown
+	//
+	//
+	//   -           <--- current line
+	//
+	// -> 1 list with 2 blank items
+	//
+	// So if the last item is an empty, it maybe a new child of the list.
+	//
+	offset := lastOffset(node)
+	lastIsEmpty := node.LastChild().ChildCount() == 0
+	indent, _ := util.IndentWidth(line, reader.LineOffset())
+
+	if indent < offset || lastIsEmpty {
+		if indent < 4 {
+			match, typ := matchesListItem(line, false) // may have a leading spaces more than 3
+			if typ != notList && match[1]-offset < 4 {
+				marker := line[match[3]-1]
+				if !list.CanContinue(marker, typ == orderedList) {
+					return Close
+				}
+				// Thematic Breaks take precedence over lists
+				if isThematicBreak(line[match[3]-1:], 0) {
+					isHeading := false
+					last := pc.LastOpenedBlock().Node
+					if ast.IsParagraph(last) {
+						c, ok := matchesSetextHeadingBar(line[match[3]-1:])
+						if ok && c == '-' {
+							isHeading = true
+						}
+					}
+					if !isHeading {
+						return Close
+					}
+				}
+				return Continue | HasChildren
+			}
+		}
+		if !lastIsEmpty {
+			return Close
+		}
+	}
+
+	if lastIsEmpty && indent < offset {
+		return Close
+	}
+
+	// Non empty items can not exist next to an empty list item
+	// with blank lines. So we need to close the current list
+	//
+	// -
+	//
+	//   foo
+	//
+	// -> 1 list with 1 blank items and 1 paragraph
+	if pc.Get(emptyListItemWithBlankLines) != nil {
+		return Close
+	}
+	return Continue | HasChildren
+}
+
+func (b *listParser) Close(node ast.Node, reader text.Reader, pc Context) {
+	list := node.(*ast.List)
+
+	for c := node.FirstChild(); c != nil && list.IsTight; c = c.NextSibling() {
+		if c.FirstChild() != nil && c.FirstChild() != c.LastChild() {
+			for c1 := c.FirstChild().NextSibling(); c1 != nil; c1 = c1.NextSibling() {
+				if bl, ok := c1.(ast.Node); ok && bl.HasBlankPreviousLines() {
+					list.IsTight = false
+					break
+				}
+			}
+		}
+		if c != node.FirstChild() {
+			if bl, ok := c.(ast.Node); ok && bl.HasBlankPreviousLines() {
+				list.IsTight = false
+			}
+		}
+	}
+
+	if list.IsTight {
+		for child := node.FirstChild(); child != nil; child = child.NextSibling() {
+			for gc := child.FirstChild(); gc != nil; {
+				paragraph, ok := gc.(*ast.Paragraph)
+				gc = gc.NextSibling()
+				if ok {
+					textBlock := ast.NewTextBlock()
+					textBlock.SetLines(paragraph.Lines())
+					child.ReplaceChild(child, paragraph, textBlock)
+				}
+			}
+		}
+	}
+}
+
+func (b *listParser) CanInterruptParagraph() bool {
+	return true
+}
+
+func (b *listParser) CanAcceptIndentedLine() bool {
+	return false
+}