1package parser
 2
 3import (
 4	"github.com/yuin/goldmark/ast"
 5	"github.com/yuin/goldmark/text"
 6	"github.com/yuin/goldmark/util"
 7)
 8
 9type listItemParser struct {
10}
11
12var defaultListItemParser = &listItemParser{}
13
14// NewListItemParser returns a new BlockParser that
15// parses list items.
16func NewListItemParser() BlockParser {
17	return defaultListItemParser
18}
19
20func (b *listItemParser) Trigger() []byte {
21	return []byte{'-', '+', '*', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'}
22}
23
24func (b *listItemParser) Open(parent ast.Node, reader text.Reader, pc Context) (ast.Node, State) {
25	list, lok := parent.(*ast.List)
26	if !lok { // list item must be a child of a list
27		return nil, NoChildren
28	}
29	offset := lastOffset(list)
30	line, _ := reader.PeekLine()
31	match, typ := matchesListItem(line, false)
32	if typ == notList {
33		return nil, NoChildren
34	}
35	if match[1]-offset > 3 {
36		return nil, NoChildren
37	}
38
39	pc.Set(emptyListItemWithBlankLines, nil)
40
41	itemOffset := calcListOffset(line, match)
42	node := ast.NewListItem(match[3] + itemOffset)
43	if match[4] < 0 || util.IsBlank(line[match[4]:match[5]]) {
44		return node, NoChildren
45	}
46
47	pos, padding := util.IndentPosition(line[match[4]:], match[4], itemOffset)
48	child := match[3] + pos
49	reader.AdvanceAndSetPadding(child, padding)
50	return node, HasChildren
51}
52
53func (b *listItemParser) Continue(node ast.Node, reader text.Reader, pc Context) State {
54	line, _ := reader.PeekLine()
55	if util.IsBlank(line) {
56		reader.Advance(len(line) - 1)
57		return Continue | HasChildren
58	}
59
60	offset := lastOffset(node.Parent())
61	isEmpty := node.ChildCount() == 0 && pc.Get(emptyListItemWithBlankLines) != nil
62	indent, _ := util.IndentWidth(line, reader.LineOffset())
63	if (isEmpty || indent < offset) && indent < 4 {
64		_, typ := matchesListItem(line, true)
65		// new list item found
66		if typ != notList {
67			pc.Set(skipListParserKey, listItemFlagValue)
68			return Close
69		}
70		if !isEmpty {
71			return Close
72		}
73	}
74	pos, padding := util.IndentPosition(line, reader.LineOffset(), offset)
75	reader.AdvanceAndSetPadding(pos, padding)
76
77	return Continue | HasChildren
78}
79
80func (b *listItemParser) Close(node ast.Node, reader text.Reader, pc Context) {
81	// nothing to do
82}
83
84func (b *listItemParser) CanInterruptParagraph() bool {
85	return true
86}
87
88func (b *listItemParser) CanAcceptIndentedLine() bool {
89	return false
90}