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Diffstat (limited to 'vendor/gopkg.in/russross/blackfriday.v2/block.go')
-rw-r--r--vendor/gopkg.in/russross/blackfriday.v2/block.go1549
1 files changed, 1549 insertions, 0 deletions
diff --git a/vendor/gopkg.in/russross/blackfriday.v2/block.go b/vendor/gopkg.in/russross/blackfriday.v2/block.go
new file mode 100644
index 0000000..d7da33f
--- /dev/null
+++ b/vendor/gopkg.in/russross/blackfriday.v2/block.go
@@ -0,0 +1,1549 @@
+//
+// Blackfriday Markdown Processor
+// Available at http://github.com/russross/blackfriday
+//
+// Copyright © 2011 Russ Ross <russ@russross.com>.
+// Distributed under the Simplified BSD License.
+// See README.md for details.
+//
+
+//
+// Functions to parse block-level elements.
+//
+
+package blackfriday
+
+import (
+ "bytes"
+ "html"
+ "regexp"
+
+ "github.com/shurcooL/sanitized_anchor_name"
+)
+
+const (
+ charEntity = "&(?:#x[a-f0-9]{1,8}|#[0-9]{1,8}|[a-z][a-z0-9]{1,31});"
+ escapable = "[!\"#$%&'()*+,./:;<=>?@[\\\\\\]^_`{|}~-]"
+)
+
+var (
+ reBackslashOrAmp = regexp.MustCompile("[\\&]")
+ reEntityOrEscapedChar = regexp.MustCompile("(?i)\\\\" + escapable + "|" + charEntity)
+)
+
+// Parse block-level data.
+// Note: this function and many that it calls assume that
+// the input buffer ends with a newline.
+func (p *Markdown) block(data []byte) {
+ // this is called recursively: enforce a maximum depth
+ if p.nesting >= p.maxNesting {
+ return
+ }
+ p.nesting++
+
+ // parse out one block-level construct at a time
+ for len(data) > 0 {
+ // prefixed heading:
+ //
+ // # Heading 1
+ // ## Heading 2
+ // ...
+ // ###### Heading 6
+ if p.isPrefixHeading(data) {
+ data = data[p.prefixHeading(data):]
+ continue
+ }
+
+ // block of preformatted HTML:
+ //
+ // <div>
+ // ...
+ // </div>
+ if data[0] == '<' {
+ if i := p.html(data, true); i > 0 {
+ data = data[i:]
+ continue
+ }
+ }
+
+ // title block
+ //
+ // % stuff
+ // % more stuff
+ // % even more stuff
+ if p.extensions&Titleblock != 0 {
+ if data[0] == '%' {
+ if i := p.titleBlock(data, true); i > 0 {
+ data = data[i:]
+ continue
+ }
+ }
+ }
+
+ // blank lines. note: returns the # of bytes to skip
+ if i := p.isEmpty(data); i > 0 {
+ data = data[i:]
+ continue
+ }
+
+ // indented code block:
+ //
+ // func max(a, b int) int {
+ // if a > b {
+ // return a
+ // }
+ // return b
+ // }
+ if p.codePrefix(data) > 0 {
+ data = data[p.code(data):]
+ continue
+ }
+
+ // fenced code block:
+ //
+ // ``` go
+ // func fact(n int) int {
+ // if n <= 1 {
+ // return n
+ // }
+ // return n * fact(n-1)
+ // }
+ // ```
+ if p.extensions&FencedCode != 0 {
+ if i := p.fencedCodeBlock(data, true); i > 0 {
+ data = data[i:]
+ continue
+ }
+ }
+
+ // horizontal rule:
+ //
+ // ------
+ // or
+ // ******
+ // or
+ // ______
+ if p.isHRule(data) {
+ p.addBlock(HorizontalRule, nil)
+ var i int
+ for i = 0; i < len(data) && data[i] != '\n'; i++ {
+ }
+ data = data[i:]
+ continue
+ }
+
+ // block quote:
+ //
+ // > A big quote I found somewhere
+ // > on the web
+ if p.quotePrefix(data) > 0 {
+ data = data[p.quote(data):]
+ continue
+ }
+
+ // table:
+ //
+ // Name | Age | Phone
+ // ------|-----|---------
+ // Bob | 31 | 555-1234
+ // Alice | 27 | 555-4321
+ if p.extensions&Tables != 0 {
+ if i := p.table(data); i > 0 {
+ data = data[i:]
+ continue
+ }
+ }
+
+ // an itemized/unordered list:
+ //
+ // * Item 1
+ // * Item 2
+ //
+ // also works with + or -
+ if p.uliPrefix(data) > 0 {
+ data = data[p.list(data, 0):]
+ continue
+ }
+
+ // a numbered/ordered list:
+ //
+ // 1. Item 1
+ // 2. Item 2
+ if p.oliPrefix(data) > 0 {
+ data = data[p.list(data, ListTypeOrdered):]
+ continue
+ }
+
+ // definition lists:
+ //
+ // Term 1
+ // : Definition a
+ // : Definition b
+ //
+ // Term 2
+ // : Definition c
+ if p.extensions&DefinitionLists != 0 {
+ if p.dliPrefix(data) > 0 {
+ data = data[p.list(data, ListTypeDefinition):]
+ continue
+ }
+ }
+
+ // anything else must look like a normal paragraph
+ // note: this finds underlined headings, too
+ data = data[p.paragraph(data):]
+ }
+
+ p.nesting--
+}
+
+func (p *Markdown) addBlock(typ NodeType, content []byte) *Node {
+ p.closeUnmatchedBlocks()
+ container := p.addChild(typ, 0)
+ container.content = content
+ return container
+}
+
+func (p *Markdown) isPrefixHeading(data []byte) bool {
+ if data[0] != '#' {
+ return false
+ }
+
+ if p.extensions&SpaceHeadings != 0 {
+ level := 0
+ for level < 6 && level < len(data) && data[level] == '#' {
+ level++
+ }
+ if level == len(data) || data[level] != ' ' {
+ return false
+ }
+ }
+ return true
+}
+
+func (p *Markdown) prefixHeading(data []byte) int {
+ level := 0
+ for level < 6 && level < len(data) && data[level] == '#' {
+ level++
+ }
+ i := skipChar(data, level, ' ')
+ end := skipUntilChar(data, i, '\n')
+ skip := end
+ id := ""
+ if p.extensions&HeadingIDs != 0 {
+ j, k := 0, 0
+ // find start/end of heading id
+ for j = i; j < end-1 && (data[j] != '{' || data[j+1] != '#'); j++ {
+ }
+ for k = j + 1; k < end && data[k] != '}'; k++ {
+ }
+ // extract heading id iff found
+ if j < end && k < end {
+ id = string(data[j+2 : k])
+ end = j
+ skip = k + 1
+ for end > 0 && data[end-1] == ' ' {
+ end--
+ }
+ }
+ }
+ for end > 0 && data[end-1] == '#' {
+ if isBackslashEscaped(data, end-1) {
+ break
+ }
+ end--
+ }
+ for end > 0 && data[end-1] == ' ' {
+ end--
+ }
+ if end > i {
+ if id == "" && p.extensions&AutoHeadingIDs != 0 {
+ id = sanitized_anchor_name.Create(string(data[i:end]))
+ }
+ block := p.addBlock(Heading, data[i:end])
+ block.HeadingID = id
+ block.Level = level
+ }
+ return skip
+}
+
+func (p *Markdown) isUnderlinedHeading(data []byte) int {
+ // test of level 1 heading
+ if data[0] == '=' {
+ i := skipChar(data, 1, '=')
+ i = skipChar(data, i, ' ')
+ if i < len(data) && data[i] == '\n' {
+ return 1
+ }
+ return 0
+ }
+
+ // test of level 2 heading
+ if data[0] == '-' {
+ i := skipChar(data, 1, '-')
+ i = skipChar(data, i, ' ')
+ if i < len(data) && data[i] == '\n' {
+ return 2
+ }
+ return 0
+ }
+
+ return 0
+}
+
+func (p *Markdown) titleBlock(data []byte, doRender bool) int {
+ if data[0] != '%' {
+ return 0
+ }
+ splitData := bytes.Split(data, []byte("\n"))
+ var i int
+ for idx, b := range splitData {
+ if !bytes.HasPrefix(b, []byte("%")) {
+ i = idx // - 1
+ break
+ }
+ }
+
+ data = bytes.Join(splitData[0:i], []byte("\n"))
+ consumed := len(data)
+ data = bytes.TrimPrefix(data, []byte("% "))
+ data = bytes.Replace(data, []byte("\n% "), []byte("\n"), -1)
+ block := p.addBlock(Heading, data)
+ block.Level = 1
+ block.IsTitleblock = true
+
+ return consumed
+}
+
+func (p *Markdown) html(data []byte, doRender bool) int {
+ var i, j int
+
+ // identify the opening tag
+ if data[0] != '<' {
+ return 0
+ }
+ curtag, tagfound := p.htmlFindTag(data[1:])
+
+ // handle special cases
+ if !tagfound {
+ // check for an HTML comment
+ if size := p.htmlComment(data, doRender); size > 0 {
+ return size
+ }
+
+ // check for an <hr> tag
+ if size := p.htmlHr(data, doRender); size > 0 {
+ return size
+ }
+
+ // no special case recognized
+ return 0
+ }
+
+ // look for an unindented matching closing tag
+ // followed by a blank line
+ found := false
+ /*
+ closetag := []byte("\n</" + curtag + ">")
+ j = len(curtag) + 1
+ for !found {
+ // scan for a closing tag at the beginning of a line
+ if skip := bytes.Index(data[j:], closetag); skip >= 0 {
+ j += skip + len(closetag)
+ } else {
+ break
+ }
+
+ // see if it is the only thing on the line
+ if skip := p.isEmpty(data[j:]); skip > 0 {
+ // see if it is followed by a blank line/eof
+ j += skip
+ if j >= len(data) {
+ found = true
+ i = j
+ } else {
+ if skip := p.isEmpty(data[j:]); skip > 0 {
+ j += skip
+ found = true
+ i = j
+ }
+ }
+ }
+ }
+ */
+
+ // if not found, try a second pass looking for indented match
+ // but not if tag is "ins" or "del" (following original Markdown.pl)
+ if !found && curtag != "ins" && curtag != "del" {
+ i = 1
+ for i < len(data) {
+ i++
+ for i < len(data) && !(data[i-1] == '<' && data[i] == '/') {
+ i++
+ }
+
+ if i+2+len(curtag) >= len(data) {
+ break
+ }
+
+ j = p.htmlFindEnd(curtag, data[i-1:])
+
+ if j > 0 {
+ i += j - 1
+ found = true
+ break
+ }
+ }
+ }
+
+ if !found {
+ return 0
+ }
+
+ // the end of the block has been found
+ if doRender {
+ // trim newlines
+ end := i
+ for end > 0 && data[end-1] == '\n' {
+ end--
+ }
+ finalizeHTMLBlock(p.addBlock(HTMLBlock, data[:end]))
+ }
+
+ return i
+}
+
+func finalizeHTMLBlock(block *Node) {
+ block.Literal = block.content
+ block.content = nil
+}
+
+// HTML comment, lax form
+func (p *Markdown) htmlComment(data []byte, doRender bool) int {
+ i := p.inlineHTMLComment(data)
+ // needs to end with a blank line
+ if j := p.isEmpty(data[i:]); j > 0 {
+ size := i + j
+ if doRender {
+ // trim trailing newlines
+ end := size
+ for end > 0 && data[end-1] == '\n' {
+ end--
+ }
+ block := p.addBlock(HTMLBlock, data[:end])
+ finalizeHTMLBlock(block)
+ }
+ return size
+ }
+ return 0
+}
+
+// HR, which is the only self-closing block tag considered
+func (p *Markdown) htmlHr(data []byte, doRender bool) int {
+ if len(data) < 4 {
+ return 0
+ }
+ if data[0] != '<' || (data[1] != 'h' && data[1] != 'H') || (data[2] != 'r' && data[2] != 'R') {
+ return 0
+ }
+ if data[3] != ' ' && data[3] != '/' && data[3] != '>' {
+ // not an <hr> tag after all; at least not a valid one
+ return 0
+ }
+ i := 3
+ for i < len(data) && data[i] != '>' && data[i] != '\n' {
+ i++
+ }
+ if i < len(data) && data[i] == '>' {
+ i++
+ if j := p.isEmpty(data[i:]); j > 0 {
+ size := i + j
+ if doRender {
+ // trim newlines
+ end := size
+ for end > 0 && data[end-1] == '\n' {
+ end--
+ }
+ finalizeHTMLBlock(p.addBlock(HTMLBlock, data[:end]))
+ }
+ return size
+ }
+ }
+ return 0
+}
+
+func (p *Markdown) htmlFindTag(data []byte) (string, bool) {
+ i := 0
+ for i < len(data) && isalnum(data[i]) {
+ i++
+ }
+ key := string(data[:i])
+ if _, ok := blockTags[key]; ok {
+ return key, true
+ }
+ return "", false
+}
+
+func (p *Markdown) htmlFindEnd(tag string, data []byte) int {
+ // assume data[0] == '<' && data[1] == '/' already tested
+ if tag == "hr" {
+ return 2
+ }
+ // check if tag is a match
+ closetag := []byte("</" + tag + ">")
+ if !bytes.HasPrefix(data, closetag) {
+ return 0
+ }
+ i := len(closetag)
+
+ // check that the rest of the line is blank
+ skip := 0
+ if skip = p.isEmpty(data[i:]); skip == 0 {
+ return 0
+ }
+ i += skip
+ skip = 0
+
+ if i >= len(data) {
+ return i
+ }
+
+ if p.extensions&LaxHTMLBlocks != 0 {
+ return i
+ }
+ if skip = p.isEmpty(data[i:]); skip == 0 {
+ // following line must be blank
+ return 0
+ }
+
+ return i + skip
+}
+
+func (*Markdown) isEmpty(data []byte) int {
+ // it is okay to call isEmpty on an empty buffer
+ if len(data) == 0 {
+ return 0
+ }
+
+ var i int
+ for i = 0; i < len(data) && data[i] != '\n'; i++ {
+ if data[i] != ' ' && data[i] != '\t' {
+ return 0
+ }
+ }
+ if i < len(data) && data[i] == '\n' {
+ i++
+ }
+ return i
+}
+
+func (*Markdown) isHRule(data []byte) bool {
+ i := 0
+
+ // skip up to three spaces
+ for i < 3 && data[i] == ' ' {
+ i++
+ }
+
+ // look at the hrule char
+ if data[i] != '*' && data[i] != '-' && data[i] != '_' {
+ return false
+ }
+ c := data[i]
+
+ // the whole line must be the char or whitespace
+ n := 0
+ for i < len(data) && data[i] != '\n' {
+ switch {
+ case data[i] == c:
+ n++
+ case data[i] != ' ':
+ return false
+ }
+ i++
+ }
+
+ return n >= 3
+}
+
+// isFenceLine checks if there's a fence line (e.g., ``` or ``` go) at the beginning of data,
+// and returns the end index if so, or 0 otherwise. It also returns the marker found.
+// If syntax is not nil, it gets set to the syntax specified in the fence line.
+func isFenceLine(data []byte, syntax *string, oldmarker string) (end int, marker string) {
+ i, size := 0, 0
+
+ // skip up to three spaces
+ for i < len(data) && i < 3 && data[i] == ' ' {
+ i++
+ }
+
+ // check for the marker characters: ~ or `
+ if i >= len(data) {
+ return 0, ""
+ }
+ if data[i] != '~' && data[i] != '`' {
+ return 0, ""
+ }
+
+ c := data[i]
+
+ // the whole line must be the same char or whitespace
+ for i < len(data) && data[i] == c {
+ size++
+ i++
+ }
+
+ // the marker char must occur at least 3 times
+ if size < 3 {
+ return 0, ""
+ }
+ marker = string(data[i-size : i])
+
+ // if this is the end marker, it must match the beginning marker
+ if oldmarker != "" && marker != oldmarker {
+ return 0, ""
+ }
+
+ // TODO(shurcooL): It's probably a good idea to simplify the 2 code paths here
+ // into one, always get the syntax, and discard it if the caller doesn't care.
+ if syntax != nil {
+ syn := 0
+ i = skipChar(data, i, ' ')
+
+ if i >= len(data) {
+ if i == len(data) {
+ return i, marker
+ }
+ return 0, ""
+ }
+
+ syntaxStart := i
+
+ if data[i] == '{' {
+ i++
+ syntaxStart++
+
+ for i < len(data) && data[i] != '}' && data[i] != '\n' {
+ syn++
+ i++
+ }
+
+ if i >= len(data) || data[i] != '}' {
+ return 0, ""
+ }
+
+ // strip all whitespace at the beginning and the end
+ // of the {} block
+ for syn > 0 && isspace(data[syntaxStart]) {
+ syntaxStart++
+ syn--
+ }
+
+ for syn > 0 && isspace(data[syntaxStart+syn-1]) {
+ syn--
+ }
+
+ i++
+ } else {
+ for i < len(data) && !isspace(data[i]) {
+ syn++
+ i++
+ }
+ }
+
+ *syntax = string(data[syntaxStart : syntaxStart+syn])
+ }
+
+ i = skipChar(data, i, ' ')
+ if i >= len(data) || data[i] != '\n' {
+ if i == len(data) {
+ return i, marker
+ }
+ return 0, ""
+ }
+ return i + 1, marker // Take newline into account.
+}
+
+// fencedCodeBlock returns the end index if data contains a fenced code block at the beginning,
+// or 0 otherwise. It writes to out if doRender is true, otherwise it has no side effects.
+// If doRender is true, a final newline is mandatory to recognize the fenced code block.
+func (p *Markdown) fencedCodeBlock(data []byte, doRender bool) int {
+ var syntax string
+ beg, marker := isFenceLine(data, &syntax, "")
+ if beg == 0 || beg >= len(data) {
+ return 0
+ }
+
+ var work bytes.Buffer
+ work.Write([]byte(syntax))
+ work.WriteByte('\n')
+
+ for {
+ // safe to assume beg < len(data)
+
+ // check for the end of the code block
+ fenceEnd, _ := isFenceLine(data[beg:], nil, marker)
+ if fenceEnd != 0 {
+ beg += fenceEnd
+ break
+ }
+
+ // copy the current line
+ end := skipUntilChar(data, beg, '\n') + 1
+
+ // did we reach the end of the buffer without a closing marker?
+ if end >= len(data) {
+ return 0
+ }
+
+ // verbatim copy to the working buffer
+ if doRender {
+ work.Write(data[beg:end])
+ }
+ beg = end
+ }
+
+ if doRender {
+ block := p.addBlock(CodeBlock, work.Bytes()) // TODO: get rid of temp buffer
+ block.IsFenced = true
+ finalizeCodeBlock(block)
+ }
+
+ return beg
+}
+
+func unescapeChar(str []byte) []byte {
+ if str[0] == '\\' {
+ return []byte{str[1]}
+ }
+ return []byte(html.UnescapeString(string(str)))
+}
+
+func unescapeString(str []byte) []byte {
+ if reBackslashOrAmp.Match(str) {
+ return reEntityOrEscapedChar.ReplaceAllFunc(str, unescapeChar)
+ }
+ return str
+}
+
+func finalizeCodeBlock(block *Node) {
+ if block.IsFenced {
+ newlinePos := bytes.IndexByte(block.content, '\n')
+ firstLine := block.content[:newlinePos]
+ rest := block.content[newlinePos+1:]
+ block.Info = unescapeString(bytes.Trim(firstLine, "\n"))
+ block.Literal = rest
+ } else {
+ block.Literal = block.content
+ }
+ block.content = nil
+}
+
+func (p *Markdown) table(data []byte) int {
+ table := p.addBlock(Table, nil)
+ i, columns := p.tableHeader(data)
+ if i == 0 {
+ p.tip = table.Parent
+ table.Unlink()
+ return 0
+ }
+
+ p.addBlock(TableBody, nil)
+
+ for i < len(data) {
+ pipes, rowStart := 0, i
+ for ; i < len(data) && data[i] != '\n'; i++ {
+ if data[i] == '|' {
+ pipes++
+ }
+ }
+
+ if pipes == 0 {
+ i = rowStart
+ break
+ }
+
+ // include the newline in data sent to tableRow
+ if i < len(data) && data[i] == '\n' {
+ i++
+ }
+ p.tableRow(data[rowStart:i], columns, false)
+ }
+
+ return i
+}
+
+// check if the specified position is preceded by an odd number of backslashes
+func isBackslashEscaped(data []byte, i int) bool {
+ backslashes := 0
+ for i-backslashes-1 >= 0 && data[i-backslashes-1] == '\\' {
+ backslashes++
+ }
+ return backslashes&1 == 1
+}
+
+func (p *Markdown) tableHeader(data []byte) (size int, columns []CellAlignFlags) {
+ i := 0
+ colCount := 1
+ for i = 0; i < len(data) && data[i] != '\n'; i++ {
+ if data[i] == '|' && !isBackslashEscaped(data, i) {
+ colCount++
+ }
+ }
+
+ // doesn't look like a table header
+ if colCount == 1 {
+ return
+ }
+
+ // include the newline in the data sent to tableRow
+ j := i
+ if j < len(data) && data[j] == '\n' {
+ j++
+ }
+ header := data[:j]
+
+ // column count ignores pipes at beginning or end of line
+ if data[0] == '|' {
+ colCount--
+ }
+ if i > 2 && data[i-1] == '|' && !isBackslashEscaped(data, i-1) {
+ colCount--
+ }
+
+ columns = make([]CellAlignFlags, colCount)
+
+ // move on to the header underline
+ i++
+ if i >= len(data) {
+ return
+ }
+
+ if data[i] == '|' && !isBackslashEscaped(data, i) {
+ i++
+ }
+ i = skipChar(data, i, ' ')
+
+ // each column header is of form: / *:?-+:? *|/ with # dashes + # colons >= 3
+ // and trailing | optional on last column
+ col := 0
+ for i < len(data) && data[i] != '\n' {
+ dashes := 0
+
+ if data[i] == ':' {
+ i++
+ columns[col] |= TableAlignmentLeft
+ dashes++
+ }
+ for i < len(data) && data[i] == '-' {
+ i++
+ dashes++
+ }
+ if i < len(data) && data[i] == ':' {
+ i++
+ columns[col] |= TableAlignmentRight
+ dashes++
+ }
+ for i < len(data) && data[i] == ' ' {
+ i++
+ }
+ if i == len(data) {
+ return
+ }
+ // end of column test is messy
+ switch {
+ case dashes < 3:
+ // not a valid column
+ return
+
+ case data[i] == '|' && !isBackslashEscaped(data, i):
+ // marker found, now skip past trailing whitespace
+ col++
+ i++
+ for i < len(data) && data[i] == ' ' {
+ i++
+ }
+
+ // trailing junk found after last column
+ if col >= colCount && i < len(data) && data[i] != '\n' {
+ return
+ }
+
+ case (data[i] != '|' || isBackslashEscaped(data, i)) && col+1 < colCount:
+ // something else found where marker was required
+ return
+
+ case data[i] == '\n':
+ // marker is optional for the last column
+ col++
+
+ default:
+ // trailing junk found after last column
+ return
+ }
+ }
+ if col != colCount {
+ return
+ }
+
+ p.addBlock(TableHead, nil)
+ p.tableRow(header, columns, true)
+ size = i
+ if size < len(data) && data[size] == '\n' {
+ size++
+ }
+ return
+}
+
+func (p *Markdown) tableRow(data []byte, columns []CellAlignFlags, header bool) {
+ p.addBlock(TableRow, nil)
+ i, col := 0, 0
+
+ if data[i] == '|' && !isBackslashEscaped(data, i) {
+ i++
+ }
+
+ for col = 0; col < len(columns) && i < len(data); col++ {
+ for i < len(data) && data[i] == ' ' {
+ i++
+ }
+
+ cellStart := i
+
+ for i < len(data) && (data[i] != '|' || isBackslashEscaped(data, i)) && data[i] != '\n' {
+ i++
+ }
+
+ cellEnd := i
+
+ // skip the end-of-cell marker, possibly taking us past end of buffer
+ i++
+
+ for cellEnd > cellStart && cellEnd-1 < len(data) && data[cellEnd-1] == ' ' {
+ cellEnd--
+ }
+
+ cell := p.addBlock(TableCell, data[cellStart:cellEnd])
+ cell.IsHeader = header
+ cell.Align = columns[col]
+ }
+
+ // pad it out with empty columns to get the right number
+ for ; col < len(columns); col++ {
+ cell := p.addBlock(TableCell, nil)
+ cell.IsHeader = header
+ cell.Align = columns[col]
+ }
+
+ // silently ignore rows with too many cells
+}
+
+// returns blockquote prefix length
+func (p *Markdown) quotePrefix(data []byte) int {
+ i := 0
+ for i < 3 && i < len(data) && data[i] == ' ' {
+ i++
+ }
+ if i < len(data) && data[i] == '>' {
+ if i+1 < len(data) && data[i+1] == ' ' {
+ return i + 2
+ }
+ return i + 1
+ }
+ return 0
+}
+
+// blockquote ends with at least one blank line
+// followed by something without a blockquote prefix
+func (p *Markdown) terminateBlockquote(data []byte, beg, end int) bool {
+ if p.isEmpty(data[beg:]) <= 0 {
+ return false
+ }
+ if end >= len(data) {
+ return true
+ }
+ return p.quotePrefix(data[end:]) == 0 && p.isEmpty(data[end:]) == 0
+}
+
+// parse a blockquote fragment
+func (p *Markdown) quote(data []byte) int {
+ block := p.addBlock(BlockQuote, nil)
+ var raw bytes.Buffer
+ beg, end := 0, 0
+ for beg < len(data) {
+ end = beg
+ // Step over whole lines, collecting them. While doing that, check for
+ // fenced code and if one's found, incorporate it altogether,
+ // irregardless of any contents inside it
+ for end < len(data) && data[end] != '\n' {
+ if p.extensions&FencedCode != 0 {
+ if i := p.fencedCodeBlock(data[end:], false); i > 0 {
+ // -1 to compensate for the extra end++ after the loop:
+ end += i - 1
+ break
+ }
+ }
+ end++
+ }
+ if end < len(data) && data[end] == '\n' {
+ end++
+ }
+ if pre := p.quotePrefix(data[beg:]); pre > 0 {
+ // skip the prefix
+ beg += pre
+ } else if p.terminateBlockquote(data, beg, end) {
+ break
+ }
+ // this line is part of the blockquote
+ raw.Write(data[beg:end])
+ beg = end
+ }
+ p.block(raw.Bytes())
+ p.finalize(block)
+ return end
+}
+
+// returns prefix length for block code
+func (p *Markdown) codePrefix(data []byte) int {
+ if len(data) >= 1 && data[0] == '\t' {
+ return 1
+ }
+ if len(data) >= 4 && data[0] == ' ' && data[1] == ' ' && data[2] == ' ' && data[3] == ' ' {
+ return 4
+ }
+ return 0
+}
+
+func (p *Markdown) code(data []byte) int {
+ var work bytes.Buffer
+
+ i := 0
+ for i < len(data) {
+ beg := i
+ for i < len(data) && data[i] != '\n' {
+ i++
+ }
+ if i < len(data) && data[i] == '\n' {
+ i++
+ }
+
+ blankline := p.isEmpty(data[beg:i]) > 0
+ if pre := p.codePrefix(data[beg:i]); pre > 0 {
+ beg += pre
+ } else if !blankline {
+ // non-empty, non-prefixed line breaks the pre
+ i = beg
+ break
+ }
+
+ // verbatim copy to the working buffer
+ if blankline {
+ work.WriteByte('\n')
+ } else {
+ work.Write(data[beg:i])
+ }
+ }
+
+ // trim all the \n off the end of work
+ workbytes := work.Bytes()
+ eol := len(workbytes)
+ for eol > 0 && workbytes[eol-1] == '\n' {
+ eol--
+ }
+ if eol != len(workbytes) {
+ work.Truncate(eol)
+ }
+
+ work.WriteByte('\n')
+
+ block := p.addBlock(CodeBlock, work.Bytes()) // TODO: get rid of temp buffer
+ block.IsFenced = false
+ finalizeCodeBlock(block)
+
+ return i
+}
+
+// returns unordered list item prefix
+func (p *Markdown) uliPrefix(data []byte) int {
+ i := 0
+ // start with up to 3 spaces
+ for i < len(data) && i < 3 && data[i] == ' ' {
+ i++
+ }
+ if i >= len(data)-1 {
+ return 0
+ }
+ // need one of {'*', '+', '-'} followed by a space or a tab
+ if (data[i] != '*' && data[i] != '+' && data[i] != '-') ||
+ (data[i+1] != ' ' && data[i+1] != '\t') {
+ return 0
+ }
+ return i + 2
+}
+
+// returns ordered list item prefix
+func (p *Markdown) oliPrefix(data []byte) int {
+ i := 0
+
+ // start with up to 3 spaces
+ for i < 3 && i < len(data) && data[i] == ' ' {
+ i++
+ }
+
+ // count the digits
+ start := i
+ for i < len(data) && data[i] >= '0' && data[i] <= '9' {
+ i++
+ }
+ if start == i || i >= len(data)-1 {
+ return 0
+ }
+
+ // we need >= 1 digits followed by a dot and a space or a tab
+ if data[i] != '.' || !(data[i+1] == ' ' || data[i+1] == '\t') {
+ return 0
+ }
+ return i + 2
+}
+
+// returns definition list item prefix
+func (p *Markdown) dliPrefix(data []byte) int {
+ if len(data) < 2 {
+ return 0
+ }
+ i := 0
+ // need a ':' followed by a space or a tab
+ if data[i] != ':' || !(data[i+1] == ' ' || data[i+1] == '\t') {
+ return 0
+ }
+ for i < len(data) && data[i] == ' ' {
+ i++
+ }
+ return i + 2
+}
+
+// parse ordered or unordered list block
+func (p *Markdown) list(data []byte, flags ListType) int {
+ i := 0
+ flags |= ListItemBeginningOfList
+ block := p.addBlock(List, nil)
+ block.ListFlags = flags
+ block.Tight = true
+
+ for i < len(data) {
+ skip := p.listItem(data[i:], &flags)
+ if flags&ListItemContainsBlock != 0 {
+ block.ListData.Tight = false
+ }
+ i += skip
+ if skip == 0 || flags&ListItemEndOfList != 0 {
+ break
+ }
+ flags &= ^ListItemBeginningOfList
+ }
+
+ above := block.Parent
+ finalizeList(block)
+ p.tip = above
+ return i
+}
+
+// Returns true if block ends with a blank line, descending if needed
+// into lists and sublists.
+func endsWithBlankLine(block *Node) bool {
+ // TODO: figure this out. Always false now.
+ for block != nil {
+ //if block.lastLineBlank {
+ //return true
+ //}
+ t := block.Type
+ if t == List || t == Item {
+ block = block.LastChild
+ } else {
+ break
+ }
+ }
+ return false
+}
+
+func finalizeList(block *Node) {
+ block.open = false
+ item := block.FirstChild
+ for item != nil {
+ // check for non-final list item ending with blank line:
+ if endsWithBlankLine(item) && item.Next != nil {
+ block.ListData.Tight = false
+ break
+ }
+ // recurse into children of list item, to see if there are spaces
+ // between any of them:
+ subItem := item.FirstChild
+ for subItem != nil {
+ if endsWithBlankLine(subItem) && (item.Next != nil || subItem.Next != nil) {
+ block.ListData.Tight = false
+ break
+ }
+ subItem = subItem.Next
+ }
+ item = item.Next
+ }
+}
+
+// Parse a single list item.
+// Assumes initial prefix is already removed if this is a sublist.
+func (p *Markdown) listItem(data []byte, flags *ListType) int {
+ // keep track of the indentation of the first line
+ itemIndent := 0
+ if data[0] == '\t' {
+ itemIndent += 4
+ } else {
+ for itemIndent < 3 && data[itemIndent] == ' ' {
+ itemIndent++
+ }
+ }
+
+ var bulletChar byte = '*'
+ i := p.uliPrefix(data)
+ if i == 0 {
+ i = p.oliPrefix(data)
+ } else {
+ bulletChar = data[i-2]
+ }
+ if i == 0 {
+ i = p.dliPrefix(data)
+ // reset definition term flag
+ if i > 0 {
+ *flags &= ^ListTypeTerm
+ }
+ }
+ if i == 0 {
+ // if in definition list, set term flag and continue
+ if *flags&ListTypeDefinition != 0 {
+ *flags |= ListTypeTerm
+ } else {
+ return 0
+ }
+ }
+
+ // skip leading whitespace on first line
+ for i < len(data) && data[i] == ' ' {
+ i++
+ }
+
+ // find the end of the line
+ line := i
+ for i > 0 && i < len(data) && data[i-1] != '\n' {
+ i++
+ }
+
+ // get working buffer
+ var raw bytes.Buffer
+
+ // put the first line into the working buffer
+ raw.Write(data[line:i])
+ line = i
+
+ // process the following lines
+ containsBlankLine := false
+ sublist := 0
+
+gatherlines:
+ for line < len(data) {
+ i++
+
+ // find the end of this line
+ for i < len(data) && data[i-1] != '\n' {
+ i++
+ }
+
+ // if it is an empty line, guess that it is part of this item
+ // and move on to the next line
+ if p.isEmpty(data[line:i]) > 0 {
+ containsBlankLine = true
+ line = i
+ continue
+ }
+
+ // calculate the indentation
+ indent := 0
+ indentIndex := 0
+ if data[line] == '\t' {
+ indentIndex++
+ indent += 4
+ } else {
+ for indent < 4 && line+indent < i && data[line+indent] == ' ' {
+ indent++
+ indentIndex++
+ }
+ }
+
+ chunk := data[line+indentIndex : i]
+
+ // evaluate how this line fits in
+ switch {
+ // is this a nested list item?
+ case (p.uliPrefix(chunk) > 0 && !p.isHRule(chunk)) ||
+ p.oliPrefix(chunk) > 0 ||
+ p.dliPrefix(chunk) > 0:
+
+ if containsBlankLine {
+ *flags |= ListItemContainsBlock
+ }
+
+ // to be a nested list, it must be indented more
+ // if not, it is the next item in the same list
+ if indent <= itemIndent {
+ break gatherlines
+ }
+
+ // is this the first item in the nested list?
+ if sublist == 0 {
+ sublist = raw.Len()
+ }
+
+ // is this a nested prefix heading?
+ case p.isPrefixHeading(chunk):
+ // if the heading is not indented, it is not nested in the list
+ // and thus ends the list
+ if containsBlankLine && indent < 4 {
+ *flags |= ListItemEndOfList
+ break gatherlines
+ }
+ *flags |= ListItemContainsBlock
+
+ // anything following an empty line is only part
+ // of this item if it is indented 4 spaces
+ // (regardless of the indentation of the beginning of the item)
+ case containsBlankLine && indent < 4:
+ if *flags&ListTypeDefinition != 0 && i < len(data)-1 {
+ // is the next item still a part of this list?
+ next := i
+ for next < len(data) && data[next] != '\n' {
+ next++
+ }
+ for next < len(data)-1 && data[next] == '\n' {
+ next++
+ }
+ if i < len(data)-1 && data[i] != ':' && data[next] != ':' {
+ *flags |= ListItemEndOfList
+ }
+ } else {
+ *flags |= ListItemEndOfList
+ }
+ break gatherlines
+
+ // a blank line means this should be parsed as a block
+ case containsBlankLine:
+ raw.WriteByte('\n')
+ *flags |= ListItemContainsBlock
+ }
+
+ // if this line was preceded by one or more blanks,
+ // re-introduce the blank into the buffer
+ if containsBlankLine {
+ containsBlankLine = false
+ raw.WriteByte('\n')
+ }
+
+ // add the line into the working buffer without prefix
+ raw.Write(data[line+indentIndex : i])
+
+ line = i
+ }
+
+ rawBytes := raw.Bytes()
+
+ block := p.addBlock(Item, nil)
+ block.ListFlags = *flags
+ block.Tight = false
+ block.BulletChar = bulletChar
+ block.Delimiter = '.' // Only '.' is possible in Markdown, but ')' will also be possible in CommonMark
+
+ // render the contents of the list item
+ if *flags&ListItemContainsBlock != 0 && *flags&ListTypeTerm == 0 {
+ // intermediate render of block item, except for definition term
+ if sublist > 0 {
+ p.block(rawBytes[:sublist])
+ p.block(rawBytes[sublist:])
+ } else {
+ p.block(rawBytes)
+ }
+ } else {
+ // intermediate render of inline item
+ if sublist > 0 {
+ child := p.addChild(Paragraph, 0)
+ child.content = rawBytes[:sublist]
+ p.block(rawBytes[sublist:])
+ } else {
+ child := p.addChild(Paragraph, 0)
+ child.content = rawBytes
+ }
+ }
+ return line
+}
+
+// render a single paragraph that has already been parsed out
+func (p *Markdown) renderParagraph(data []byte) {
+ if len(data) == 0 {
+ return
+ }
+
+ // trim leading spaces
+ beg := 0
+ for data[beg] == ' ' {
+ beg++
+ }
+
+ end := len(data)
+ // trim trailing newline
+ if data[len(data)-1] == '\n' {
+ end--
+ }
+
+ // trim trailing spaces
+ for end > beg && data[end-1] == ' ' {
+ end--
+ }
+
+ p.addBlock(Paragraph, data[beg:end])
+}
+
+func (p *Markdown) paragraph(data []byte) int {
+ // prev: index of 1st char of previous line
+ // line: index of 1st char of current line
+ // i: index of cursor/end of current line
+ var prev, line, i int
+ tabSize := TabSizeDefault
+ if p.extensions&TabSizeEight != 0 {
+ tabSize = TabSizeDouble
+ }
+ // keep going until we find something to mark the end of the paragraph
+ for i < len(data) {
+ // mark the beginning of the current line
+ prev = line
+ current := data[i:]
+ line = i
+
+ // did we find a reference or a footnote? If so, end a paragraph
+ // preceding it and report that we have consumed up to the end of that
+ // reference:
+ if refEnd := isReference(p, current, tabSize); refEnd > 0 {
+ p.renderParagraph(data[:i])
+ return i + refEnd
+ }
+
+ // did we find a blank line marking the end of the paragraph?
+ if n := p.isEmpty(current); n > 0 {
+ // did this blank line followed by a definition list item?
+ if p.extensions&DefinitionLists != 0 {
+ if i < len(data)-1 && data[i+1] == ':' {
+ return p.list(data[prev:], ListTypeDefinition)
+ }
+ }
+
+ p.renderParagraph(data[:i])
+ return i + n
+ }
+
+ // an underline under some text marks a heading, so our paragraph ended on prev line
+ if i > 0 {
+ if level := p.isUnderlinedHeading(current); level > 0 {
+ // render the paragraph
+ p.renderParagraph(data[:prev])
+
+ // ignore leading and trailing whitespace
+ eol := i - 1
+ for prev < eol && data[prev] == ' ' {
+ prev++
+ }
+ for eol > prev && data[eol-1] == ' ' {
+ eol--
+ }
+
+ id := ""
+ if p.extensions&AutoHeadingIDs != 0 {
+ id = sanitized_anchor_name.Create(string(data[prev:eol]))
+ }
+
+ block := p.addBlock(Heading, data[prev:eol])
+ block.Level = level
+ block.HeadingID = id
+
+ // find the end of the underline
+ for i < len(data) && data[i] != '\n' {
+ i++
+ }
+ return i
+ }
+ }
+
+ // if the next line starts a block of HTML, then the paragraph ends here
+ if p.extensions&LaxHTMLBlocks != 0 {
+ if data[i] == '<' && p.html(current, false) > 0 {
+ // rewind to before the HTML block
+ p.renderParagraph(data[:i])
+ return i
+ }
+ }
+
+ // if there's a prefixed heading or a horizontal rule after this, paragraph is over
+ if p.isPrefixHeading(current) || p.isHRule(current) {
+ p.renderParagraph(data[:i])
+ return i
+ }
+
+ // if there's a fenced code block, paragraph is over
+ if p.extensions&FencedCode != 0 {
+ if p.fencedCodeBlock(current, false) > 0 {
+ p.renderParagraph(data[:i])
+ return i
+ }
+ }
+
+ // if there's a definition list item, prev line is a definition term
+ if p.extensions&DefinitionLists != 0 {
+ if p.dliPrefix(current) != 0 {
+ ret := p.list(data[prev:], ListTypeDefinition)
+ return ret
+ }
+ }
+
+ // if there's a list after this, paragraph is over
+ if p.extensions&NoEmptyLineBeforeBlock != 0 {
+ if p.uliPrefix(current) != 0 ||
+ p.oliPrefix(current) != 0 ||
+ p.quotePrefix(current) != 0 ||
+ p.codePrefix(current) != 0 {
+ p.renderParagraph(data[:i])
+ return i
+ }
+ }
+
+ // otherwise, scan to the beginning of the next line
+ nl := bytes.IndexByte(data[i:], '\n')
+ if nl >= 0 {
+ i += nl + 1
+ } else {
+ i += len(data[i:])
+ }
+ }
+
+ p.renderParagraph(data[:i])
+ return i
+}
+
+func skipChar(data []byte, start int, char byte) int {
+ i := start
+ for i < len(data) && data[i] == char {
+ i++
+ }
+ return i
+}
+
+func skipUntilChar(text []byte, start int, char byte) int {
+ i := start
+ for i < len(text) && text[i] != char {
+ i++
+ }
+ return i
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-29 07:07:39 +0000