gotosocial/vendor/github.com/yuin/goldmark/parser/fcode_block.go
Autumn! eb08529f35
[chore/bugfix] Switch markdown from blackfriday to goldmark (#1267)
Co-authored-by: Autumn! <autumnull@posteo.net>
2022-12-16 12:20:22 +01:00

121 lines
3.1 KiB
Go

package parser
import (
"bytes"
"github.com/yuin/goldmark/ast"
"github.com/yuin/goldmark/text"
"github.com/yuin/goldmark/util"
)
type fencedCodeBlockParser struct {
}
var defaultFencedCodeBlockParser = &fencedCodeBlockParser{}
// NewFencedCodeBlockParser returns a new BlockParser that
// parses fenced code blocks.
func NewFencedCodeBlockParser() BlockParser {
return defaultFencedCodeBlockParser
}
type fenceData struct {
char byte
indent int
length int
node ast.Node
}
var fencedCodeBlockInfoKey = NewContextKey()
func (b *fencedCodeBlockParser) Trigger() []byte {
return []byte{'~', '`'}
}
func (b *fencedCodeBlockParser) Open(parent ast.Node, reader text.Reader, pc Context) (ast.Node, State) {
line, segment := reader.PeekLine()
pos := pc.BlockOffset()
if pos < 0 || (line[pos] != '`' && line[pos] != '~') {
return nil, NoChildren
}
findent := pos
fenceChar := line[pos]
i := pos
for ; i < len(line) && line[i] == fenceChar; i++ {
}
oFenceLength := i - pos
if oFenceLength < 3 {
return nil, NoChildren
}
var info *ast.Text
if i < len(line)-1 {
rest := line[i:]
left := util.TrimLeftSpaceLength(rest)
right := util.TrimRightSpaceLength(rest)
if left < len(rest)-right {
infoStart, infoStop := segment.Start-segment.Padding+i+left, segment.Stop-right
value := rest[left : len(rest)-right]
if fenceChar == '`' && bytes.IndexByte(value, '`') > -1 {
return nil, NoChildren
} else if infoStart != infoStop {
info = ast.NewTextSegment(text.NewSegment(infoStart, infoStop))
}
}
}
node := ast.NewFencedCodeBlock(info)
pc.Set(fencedCodeBlockInfoKey, &fenceData{fenceChar, findent, oFenceLength, node})
return node, NoChildren
}
func (b *fencedCodeBlockParser) Continue(node ast.Node, reader text.Reader, pc Context) State {
line, segment := reader.PeekLine()
fdata := pc.Get(fencedCodeBlockInfoKey).(*fenceData)
w, pos := util.IndentWidth(line, reader.LineOffset())
if w < 4 {
i := pos
for ; i < len(line) && line[i] == fdata.char; i++ {
}
length := i - pos
if length >= fdata.length && util.IsBlank(line[i:]) {
newline := 1
if line[len(line)-1] != '\n' {
newline = 0
}
reader.Advance(segment.Stop - segment.Start - newline + segment.Padding)
return Close
}
}
pos, padding := util.IndentPositionPadding(line, reader.LineOffset(), segment.Padding, fdata.indent)
if pos < 0 {
pos = util.FirstNonSpacePosition(line)
if pos < 0 {
pos = 0
}
padding = 0
}
seg := text.NewSegmentPadding(segment.Start+pos, segment.Stop, padding)
// if code block line starts with a tab, keep a tab as it is.
if padding != 0 {
preserveLeadingTabInCodeBlock(&seg, reader, fdata.indent)
}
node.Lines().Append(seg)
reader.AdvanceAndSetPadding(segment.Stop-segment.Start-pos-1, padding)
return Continue | NoChildren
}
func (b *fencedCodeBlockParser) Close(node ast.Node, reader text.Reader, pc Context) {
fdata := pc.Get(fencedCodeBlockInfoKey).(*fenceData)
if fdata.node == node {
pc.Set(fencedCodeBlockInfoKey, nil)
}
}
func (b *fencedCodeBlockParser) CanInterruptParagraph() bool {
return true
}
func (b *fencedCodeBlockParser) CanAcceptIndentedLine() bool {
return false
}