gitea/vendor/github.com/yuin/goldmark/parser/list.go
zeripath 27757714d0 Change markdown rendering from blackfriday to goldmark (#9533)
* Move to goldmark

Markdown rendering moved from blackfriday to the goldmark.

Multiple subtle changes required to the goldmark extensions to keep
current rendering and defaults.

Can go further with goldmark linkify and have this work within markdown
rendering making the link processor unnecessary.

Need to think about how to go about allowing extensions - at present it
seems that these would be hard to do without recompilation.

* linter fixes

Co-authored-by: Lauris BH <lauris@nix.lv>
2019-12-31 03:53:28 +02:00

251 lines
5.6 KiB
Go

package parser
import (
"github.com/yuin/goldmark/ast"
"github.com/yuin/goldmark/text"
"github.com/yuin/goldmark/util"
"strconv"
)
type listItemType int
const (
notList listItemType = iota
bulletList
orderedList
)
// 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(skipListParser) != nil {
pc.Set(skipListParser, 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[5]-match[4] == 1 {
return nil, NoChildren
}
}
marker := line[match[3]-1]
node := ast.NewList(marker)
if start > -1 {
node.Start = start
}
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) {
// A list item can begin with at most one blank line
if node.ChildCount() == 1 && node.LastChild().ChildCount() == 0 {
return Close
}
return Continue | HasChildren
}
// Thematic Breaks take precedence over lists
if isThematicBreak(line, reader.LineOffset()) {
isHeading := false
last := pc.LastOpenedBlock().Node
if ast.IsParagraph(last) {
c, ok := matchesSetextHeadingBar(line)
if ok && c == '-' {
isHeading = true
}
}
if !isHeading {
return Close
}
}
// "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.
offset := lastOffset(node)
indent, _ := util.IndentWidth(line, reader.LineOffset())
if indent < offset {
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
}
return Continue | HasChildren
}
}
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; gc = gc.NextSibling() {
paragraph, ok := gc.(*ast.Paragraph)
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
}