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 }