forked from mirrors/gotosocial
eb08529f35
Co-authored-by: Autumn! <autumnull@posteo.net>
121 lines
3.1 KiB
Go
121 lines
3.1 KiB
Go
package parser
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import (
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"bytes"
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"github.com/yuin/goldmark/ast"
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"github.com/yuin/goldmark/text"
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"github.com/yuin/goldmark/util"
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)
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type fencedCodeBlockParser struct {
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}
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var defaultFencedCodeBlockParser = &fencedCodeBlockParser{}
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// NewFencedCodeBlockParser returns a new BlockParser that
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// parses fenced code blocks.
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func NewFencedCodeBlockParser() BlockParser {
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return defaultFencedCodeBlockParser
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}
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type fenceData struct {
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char byte
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indent int
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length int
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node ast.Node
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}
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var fencedCodeBlockInfoKey = NewContextKey()
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func (b *fencedCodeBlockParser) Trigger() []byte {
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return []byte{'~', '`'}
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}
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func (b *fencedCodeBlockParser) Open(parent ast.Node, reader text.Reader, pc Context) (ast.Node, State) {
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line, segment := reader.PeekLine()
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pos := pc.BlockOffset()
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if pos < 0 || (line[pos] != '`' && line[pos] != '~') {
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return nil, NoChildren
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}
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findent := pos
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fenceChar := line[pos]
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i := pos
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for ; i < len(line) && line[i] == fenceChar; i++ {
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}
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oFenceLength := i - pos
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if oFenceLength < 3 {
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return nil, NoChildren
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}
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var info *ast.Text
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if i < len(line)-1 {
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rest := line[i:]
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left := util.TrimLeftSpaceLength(rest)
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right := util.TrimRightSpaceLength(rest)
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if left < len(rest)-right {
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infoStart, infoStop := segment.Start-segment.Padding+i+left, segment.Stop-right
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value := rest[left : len(rest)-right]
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if fenceChar == '`' && bytes.IndexByte(value, '`') > -1 {
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return nil, NoChildren
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} else if infoStart != infoStop {
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info = ast.NewTextSegment(text.NewSegment(infoStart, infoStop))
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}
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}
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}
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node := ast.NewFencedCodeBlock(info)
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pc.Set(fencedCodeBlockInfoKey, &fenceData{fenceChar, findent, oFenceLength, node})
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return node, NoChildren
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}
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func (b *fencedCodeBlockParser) Continue(node ast.Node, reader text.Reader, pc Context) State {
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line, segment := reader.PeekLine()
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fdata := pc.Get(fencedCodeBlockInfoKey).(*fenceData)
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w, pos := util.IndentWidth(line, reader.LineOffset())
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if w < 4 {
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i := pos
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for ; i < len(line) && line[i] == fdata.char; i++ {
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}
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length := i - pos
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if length >= fdata.length && util.IsBlank(line[i:]) {
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newline := 1
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if line[len(line)-1] != '\n' {
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newline = 0
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}
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reader.Advance(segment.Stop - segment.Start - newline + segment.Padding)
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return Close
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}
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}
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pos, padding := util.IndentPositionPadding(line, reader.LineOffset(), segment.Padding, fdata.indent)
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if pos < 0 {
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pos = util.FirstNonSpacePosition(line)
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if pos < 0 {
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pos = 0
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}
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padding = 0
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}
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seg := text.NewSegmentPadding(segment.Start+pos, segment.Stop, padding)
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// if code block line starts with a tab, keep a tab as it is.
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if padding != 0 {
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preserveLeadingTabInCodeBlock(&seg, reader, fdata.indent)
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}
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node.Lines().Append(seg)
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reader.AdvanceAndSetPadding(segment.Stop-segment.Start-pos-1, padding)
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return Continue | NoChildren
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}
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func (b *fencedCodeBlockParser) Close(node ast.Node, reader text.Reader, pc Context) {
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fdata := pc.Get(fencedCodeBlockInfoKey).(*fenceData)
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if fdata.node == node {
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pc.Set(fencedCodeBlockInfoKey, nil)
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}
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}
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func (b *fencedCodeBlockParser) CanInterruptParagraph() bool {
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return true
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}
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func (b *fencedCodeBlockParser) CanAcceptIndentedLine() bool {
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return false
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}
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