githaven-fork/vendor/github.com/yuin/goldmark/parser/setext_headings.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

127 lines
3.0 KiB
Go
Vendored

package parser
import (
"github.com/yuin/goldmark/ast"
"github.com/yuin/goldmark/text"
"github.com/yuin/goldmark/util"
)
var temporaryParagraphKey = NewContextKey()
type setextHeadingParser struct {
HeadingConfig
}
func matchesSetextHeadingBar(line []byte) (byte, bool) {
start := 0
end := len(line)
space := util.TrimLeftLength(line, []byte{' '})
if space > 3 {
return 0, false
}
start += space
level1 := util.TrimLeftLength(line[start:end], []byte{'='})
c := byte('=')
var level2 int
if level1 == 0 {
level2 = util.TrimLeftLength(line[start:end], []byte{'-'})
c = '-'
}
if util.IsSpace(line[end-1]) {
end -= util.TrimRightSpaceLength(line[start:end])
}
if !((level1 > 0 && start+level1 == end) || (level2 > 0 && start+level2 == end)) {
return 0, false
}
return c, true
}
// NewSetextHeadingParser return a new BlockParser that can parse Setext headings.
func NewSetextHeadingParser(opts ...HeadingOption) BlockParser {
p := &setextHeadingParser{}
for _, o := range opts {
o.SetHeadingOption(&p.HeadingConfig)
}
return p
}
func (b *setextHeadingParser) Trigger() []byte {
return []byte{'-', '='}
}
func (b *setextHeadingParser) Open(parent ast.Node, reader text.Reader, pc Context) (ast.Node, State) {
last := pc.LastOpenedBlock().Node
if last == nil {
return nil, NoChildren
}
paragraph, ok := last.(*ast.Paragraph)
if !ok || paragraph.Parent() != parent {
return nil, NoChildren
}
line, segment := reader.PeekLine()
c, ok := matchesSetextHeadingBar(line)
if !ok {
return nil, NoChildren
}
level := 1
if c == '-' {
level = 2
}
node := ast.NewHeading(level)
node.Lines().Append(segment)
pc.Set(temporaryParagraphKey, last)
return node, NoChildren | RequireParagraph
}
func (b *setextHeadingParser) Continue(node ast.Node, reader text.Reader, pc Context) State {
return Close
}
func (b *setextHeadingParser) Close(node ast.Node, reader text.Reader, pc Context) {
heading := node.(*ast.Heading)
segment := node.Lines().At(0)
heading.Lines().Clear()
tmp := pc.Get(temporaryParagraphKey).(*ast.Paragraph)
pc.Set(temporaryParagraphKey, nil)
if tmp.Lines().Len() == 0 {
next := heading.NextSibling()
segment = segment.TrimLeftSpace(reader.Source())
if next == nil || !ast.IsParagraph(next) {
para := ast.NewParagraph()
para.Lines().Append(segment)
heading.Parent().InsertAfter(heading.Parent(), heading, para)
} else {
next.(ast.Node).Lines().Unshift(segment)
}
heading.Parent().RemoveChild(heading.Parent(), heading)
} else {
heading.SetLines(tmp.Lines())
heading.SetBlankPreviousLines(tmp.HasBlankPreviousLines())
tp := tmp.Parent()
if tp != nil {
tp.RemoveChild(tp, tmp)
}
}
if b.Attribute {
parseLastLineAttributes(node, reader, pc)
}
if b.AutoHeadingID {
id, ok := node.AttributeString("id")
if !ok {
generateAutoHeadingID(heading, reader, pc)
} else {
pc.IDs().Put(id.([]byte))
}
}
}
func (b *setextHeadingParser) CanInterruptParagraph() bool {
return true
}
func (b *setextHeadingParser) CanAcceptIndentedLine() bool {
return false
}