vendor test tools in submodule

Instead of using the main module we should vendor the test tools in a
different directory. That way we do not add extra dependencies to the
main module which can be problemetic for packages or other users.

This is already done in buildah so this makes us more consitent.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

1 files changed, 1612 insertions, 0 deletions

diff --git a/test/tools/vendor/github.com/russross/blackfriday/v2/block.go b/test/tools/vendor/github.com/russross/blackfriday/v2/block.go
new file mode 100644
index 000000000..dcd61e6e3
--- /dev/null
+++ b/test/tools/vendor/github.com/russross/blackfriday/v2/block.go
@@ -0,0 +1,1612 @@
+//
+// 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"
+	"strings"
+	"unicode"
+)
+
+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 = SanitizedAnchorName(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 info is not nil, it gets set to the syntax specified in the fence line.
+func isFenceLine(data []byte, info *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 info string, and discard it if the caller doesn't care.
+	if info != nil {
+		infoLength := 0
+		i = skipChar(data, i, ' ')
+
+		if i >= len(data) {
+			if i == len(data) {
+				return i, marker
+			}
+			return 0, ""
+		}
+
+		infoStart := i
+
+		if data[i] == '{' {
+			i++
+			infoStart++
+
+			for i < len(data) && data[i] != '}' && data[i] != '\n' {
+				infoLength++
+				i++
+			}
+
+			if i >= len(data) || data[i] != '}' {
+				return 0, ""
+			}
+
+			// strip all whitespace at the beginning and the end
+			// of the {} block
+			for infoLength > 0 && isspace(data[infoStart]) {
+				infoStart++
+				infoLength--
+			}
+
+			for infoLength > 0 && isspace(data[infoStart+infoLength-1]) {
+				infoLength--
+			}
+			i++
+			i = skipChar(data, i, ' ')
+		} else {
+			for i < len(data) && !isverticalspace(data[i]) {
+				infoLength++
+				i++
+			}
+		}
+
+		*info = strings.TrimSpace(string(data[infoStart : infoStart+infoLength]))
+	}
+
+	if i == len(data) {
+		return i, marker
+	}
+	if i > len(data) || data[i] != '\n' {
+		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 info string
+	beg, marker := isFenceLine(data, &info, "")
+	if beg == 0 || beg >= len(data) {
+		return 0
+	}
+	fenceLength := beg - 1
+
+	var work bytes.Buffer
+	work.Write([]byte(info))
+	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
+		block.FenceLength = fenceLength
+		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 the list item is not the same type as its parent list
+func (p *Markdown) listTypeChanged(data []byte, flags *ListType) bool {
+	if p.dliPrefix(data) > 0 && *flags&ListTypeDefinition == 0 {
+		return true
+	} else if p.oliPrefix(data) > 0 && *flags&ListTypeOrdered == 0 {
+		return true
+	} else if p.uliPrefix(data) > 0 && (*flags&ListTypeOrdered != 0 || *flags&ListTypeDefinition != 0) {
+		return true
+	}
+	return false
+}
+
+// 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
+	codeBlockMarker := ""
+
+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]
+
+		if p.extensions&FencedCode != 0 {
+			// determine if in or out of codeblock
+			// if in codeblock, ignore normal list processing
+			_, marker := isFenceLine(chunk, nil, codeBlockMarker)
+			if marker != "" {
+				if codeBlockMarker == "" {
+					// start of codeblock
+					codeBlockMarker = marker
+				} else {
+					// end of codeblock.
+					codeBlockMarker = ""
+				}
+			}
+			// we are in a codeblock, write line, and continue
+			if codeBlockMarker != "" || marker != "" {
+				raw.Write(data[line+indentIndex : i])
+				line = i
+				continue gatherlines
+			}
+		}
+
+		// 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:
+
+			// to be a nested list, it must be indented more
+			// if not, it is either a different kind of list
+			// or the next item in the same list
+			if indent <= itemIndent {
+				if p.listTypeChanged(chunk, flags) {
+					*flags |= ListItemEndOfList
+				} else if containsBlankLine {
+					*flags |= ListItemContainsBlock
+				}
+
+				break gatherlines
+			}
+
+			if containsBlankLine {
+				*flags |= ListItemContainsBlock
+			}
+
+			// 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 = SanitizedAnchorName(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
+}
+
+// SanitizedAnchorName returns a sanitized anchor name for the given text.
+//
+// It implements the algorithm specified in the package comment.
+func SanitizedAnchorName(text string) string {
+	var anchorName []rune
+	futureDash := false
+	for _, r := range text {
+		switch {
+		case unicode.IsLetter(r) || unicode.IsNumber(r):
+			if futureDash && len(anchorName) > 0 {
+				anchorName = append(anchorName, '-')
+			}
+			futureDash = false
+			anchorName = append(anchorName, unicode.ToLower(r))
+		default:
+			futureDash = true
+		}
+	}
+	return string(anchorName)
+}