forgejo-federation/vendor/github.com/yuin/goldmark/parser/atx_heading.go

243 lines
5.6 KiB
Go
Vendored

package parser
import (
"github.com/yuin/goldmark/ast"
"github.com/yuin/goldmark/text"
"github.com/yuin/goldmark/util"
)
// A HeadingConfig struct is a data structure that holds configuration of the renderers related to headings.
type HeadingConfig struct {
AutoHeadingID bool
Attribute bool
}
// SetOption implements SetOptioner.
func (b *HeadingConfig) SetOption(name OptionName, value interface{}) {
switch name {
case optAutoHeadingID:
b.AutoHeadingID = true
case optAttribute:
b.Attribute = true
}
}
// A HeadingOption interface sets options for heading parsers.
type HeadingOption interface {
Option
SetHeadingOption(*HeadingConfig)
}
// AutoHeadingID is an option name that enables auto IDs for headings.
const optAutoHeadingID OptionName = "AutoHeadingID"
type withAutoHeadingID struct {
}
func (o *withAutoHeadingID) SetParserOption(c *Config) {
c.Options[optAutoHeadingID] = true
}
func (o *withAutoHeadingID) SetHeadingOption(p *HeadingConfig) {
p.AutoHeadingID = true
}
// WithAutoHeadingID is a functional option that enables custom heading ids and
// auto generated heading ids.
func WithAutoHeadingID() HeadingOption {
return &withAutoHeadingID{}
}
type withHeadingAttribute struct {
Option
}
func (o *withHeadingAttribute) SetHeadingOption(p *HeadingConfig) {
p.Attribute = true
}
// WithHeadingAttribute is a functional option that enables custom heading attributes.
func WithHeadingAttribute() HeadingOption {
return &withHeadingAttribute{WithAttribute()}
}
type atxHeadingParser struct {
HeadingConfig
}
// NewATXHeadingParser return a new BlockParser that can parse ATX headings.
func NewATXHeadingParser(opts ...HeadingOption) BlockParser {
p := &atxHeadingParser{}
for _, o := range opts {
o.SetHeadingOption(&p.HeadingConfig)
}
return p
}
func (b *atxHeadingParser) Trigger() []byte {
return []byte{'#'}
}
func (b *atxHeadingParser) Open(parent ast.Node, reader text.Reader, pc Context) (ast.Node, State) {
line, segment := reader.PeekLine()
pos := pc.BlockOffset()
if pos < 0 {
return nil, NoChildren
}
i := pos
for ; i < len(line) && line[i] == '#'; i++ {
}
level := i - pos
if i == pos || level > 6 {
return nil, NoChildren
}
l := util.TrimLeftSpaceLength(line[i:])
if l == 0 {
return nil, NoChildren
}
start := i + l
if start >= len(line) {
start = len(line) - 1
}
origstart := start
stop := len(line) - util.TrimRightSpaceLength(line)
node := ast.NewHeading(level)
parsed := false
if b.Attribute { // handles special case like ### heading ### {#id}
start--
closureClose := -1
closureOpen := -1
for j := start; j < stop; {
c := line[j]
if util.IsEscapedPunctuation(line, j) {
j += 2
} else if util.IsSpace(c) && j < stop-1 && line[j+1] == '#' {
closureOpen = j + 1
k := j + 1
for ; k < stop && line[k] == '#'; k++ {
}
closureClose = k
break
} else {
j++
}
}
if closureClose > 0 {
reader.Advance(closureClose)
attrs, ok := ParseAttributes(reader)
rest, _ := reader.PeekLine()
parsed = ok && util.IsBlank(rest)
if parsed {
for _, attr := range attrs {
node.SetAttribute(attr.Name, attr.Value)
}
node.Lines().Append(text.NewSegment(segment.Start+start+1-segment.Padding, segment.Start+closureOpen-segment.Padding))
}
}
}
if !parsed {
start = origstart
stop := len(line) - util.TrimRightSpaceLength(line)
if stop <= start { // empty headings like '##[space]'
stop = start
} else {
i = stop - 1
for ; line[i] == '#' && i >= start; i-- {
}
if i != stop-1 && !util.IsSpace(line[i]) {
i = stop - 1
}
i++
stop = i
}
if len(util.TrimRight(line[start:stop], []byte{'#'})) != 0 { // empty heading like '### ###'
node.Lines().Append(text.NewSegment(segment.Start+start-segment.Padding, segment.Start+stop-segment.Padding))
}
}
return node, NoChildren
}
func (b *atxHeadingParser) Continue(node ast.Node, reader text.Reader, pc Context) State {
return Close
}
func (b *atxHeadingParser) Close(node ast.Node, reader text.Reader, pc Context) {
if b.Attribute {
_, ok := node.AttributeString("id")
if !ok {
parseLastLineAttributes(node, reader, pc)
}
}
if b.AutoHeadingID {
id, ok := node.AttributeString("id")
if !ok {
generateAutoHeadingID(node.(*ast.Heading), reader, pc)
} else {
pc.IDs().Put(id.([]byte))
}
}
}
func (b *atxHeadingParser) CanInterruptParagraph() bool {
return true
}
func (b *atxHeadingParser) CanAcceptIndentedLine() bool {
return false
}
func generateAutoHeadingID(node *ast.Heading, reader text.Reader, pc Context) {
var line []byte
lastIndex := node.Lines().Len() - 1
if lastIndex > -1 {
lastLine := node.Lines().At(lastIndex)
line = lastLine.Value(reader.Source())
}
headingID := pc.IDs().Generate(line, ast.KindHeading)
node.SetAttribute(attrNameID, headingID)
}
func parseLastLineAttributes(node ast.Node, reader text.Reader, pc Context) {
lastIndex := node.Lines().Len() - 1
if lastIndex < 0 { // empty headings
return
}
lastLine := node.Lines().At(lastIndex)
line := lastLine.Value(reader.Source())
lr := text.NewReader(line)
var attrs Attributes
var ok bool
var start text.Segment
var sl int
var end text.Segment
for {
c := lr.Peek()
if c == text.EOF {
break
}
if c == '\\' {
lr.Advance(1)
if lr.Peek() == '{' {
lr.Advance(1)
}
continue
}
if c == '{' {
sl, start = lr.Position()
attrs, ok = ParseAttributes(lr)
_, end = lr.Position()
lr.SetPosition(sl, start)
}
lr.Advance(1)
}
if ok && util.IsBlank(line[end.Start:]) {
for _, attr := range attrs {
node.SetAttribute(attr.Name, attr.Value)
}
lastLine.Stop = lastLine.Start + start.Start
node.Lines().Set(lastIndex, lastLine)
}
}