Change markdown rendering from blackfriday to goldmark (#9533)

* Move to goldmark

Markdown rendering moved from blackfriday to the goldmark.

Multiple subtle changes required to the goldmark extensions to keep
current rendering and defaults.

Can go further with goldmark linkify and have this work within markdown
rendering making the link processor unnecessary.

Need to think about how to go about allowing extensions - at present it
seems that these would be hard to do without recompilation.

* linter fixes

Co-authored-by: Lauris BH <lauris@nix.lv>
This commit is contained in:
zeripath 2019-12-31 01:53:28 +00:00 committed by Lauris BH
parent 0c07f1de5b
commit 27757714d0
83 changed files with 13838 additions and 6297 deletions

View file

@ -1,457 +0,0 @@
//
// 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.
//
//
//
// SmartyPants rendering
//
//
package blackfriday
import (
"bytes"
"io"
)
// SPRenderer is a struct containing state of a Smartypants renderer.
type SPRenderer struct {
inSingleQuote bool
inDoubleQuote bool
callbacks [256]smartCallback
}
func wordBoundary(c byte) bool {
return c == 0 || isspace(c) || ispunct(c)
}
func tolower(c byte) byte {
if c >= 'A' && c <= 'Z' {
return c - 'A' + 'a'
}
return c
}
func isdigit(c byte) bool {
return c >= '0' && c <= '9'
}
func smartQuoteHelper(out *bytes.Buffer, previousChar byte, nextChar byte, quote byte, isOpen *bool, addNBSP bool) bool {
// edge of the buffer is likely to be a tag that we don't get to see,
// so we treat it like text sometimes
// enumerate all sixteen possibilities for (previousChar, nextChar)
// each can be one of {0, space, punct, other}
switch {
case previousChar == 0 && nextChar == 0:
// context is not any help here, so toggle
*isOpen = !*isOpen
case isspace(previousChar) && nextChar == 0:
// [ "] might be [ "<code>foo...]
*isOpen = true
case ispunct(previousChar) && nextChar == 0:
// [!"] hmm... could be [Run!"] or [("<code>...]
*isOpen = false
case /* isnormal(previousChar) && */ nextChar == 0:
// [a"] is probably a close
*isOpen = false
case previousChar == 0 && isspace(nextChar):
// [" ] might be [...foo</code>" ]
*isOpen = false
case isspace(previousChar) && isspace(nextChar):
// [ " ] context is not any help here, so toggle
*isOpen = !*isOpen
case ispunct(previousChar) && isspace(nextChar):
// [!" ] is probably a close
*isOpen = false
case /* isnormal(previousChar) && */ isspace(nextChar):
// [a" ] this is one of the easy cases
*isOpen = false
case previousChar == 0 && ispunct(nextChar):
// ["!] hmm... could be ["$1.95] or [</code>"!...]
*isOpen = false
case isspace(previousChar) && ispunct(nextChar):
// [ "!] looks more like [ "$1.95]
*isOpen = true
case ispunct(previousChar) && ispunct(nextChar):
// [!"!] context is not any help here, so toggle
*isOpen = !*isOpen
case /* isnormal(previousChar) && */ ispunct(nextChar):
// [a"!] is probably a close
*isOpen = false
case previousChar == 0 /* && isnormal(nextChar) */ :
// ["a] is probably an open
*isOpen = true
case isspace(previousChar) /* && isnormal(nextChar) */ :
// [ "a] this is one of the easy cases
*isOpen = true
case ispunct(previousChar) /* && isnormal(nextChar) */ :
// [!"a] is probably an open
*isOpen = true
default:
// [a'b] maybe a contraction?
*isOpen = false
}
// Note that with the limited lookahead, this non-breaking
// space will also be appended to single double quotes.
if addNBSP && !*isOpen {
out.WriteString("&nbsp;")
}
out.WriteByte('&')
if *isOpen {
out.WriteByte('l')
} else {
out.WriteByte('r')
}
out.WriteByte(quote)
out.WriteString("quo;")
if addNBSP && *isOpen {
out.WriteString("&nbsp;")
}
return true
}
func (r *SPRenderer) smartSingleQuote(out *bytes.Buffer, previousChar byte, text []byte) int {
if len(text) >= 2 {
t1 := tolower(text[1])
if t1 == '\'' {
nextChar := byte(0)
if len(text) >= 3 {
nextChar = text[2]
}
if smartQuoteHelper(out, previousChar, nextChar, 'd', &r.inDoubleQuote, false) {
return 1
}
}
if (t1 == 's' || t1 == 't' || t1 == 'm' || t1 == 'd') && (len(text) < 3 || wordBoundary(text[2])) {
out.WriteString("&rsquo;")
return 0
}
if len(text) >= 3 {
t2 := tolower(text[2])
if ((t1 == 'r' && t2 == 'e') || (t1 == 'l' && t2 == 'l') || (t1 == 'v' && t2 == 'e')) &&
(len(text) < 4 || wordBoundary(text[3])) {
out.WriteString("&rsquo;")
return 0
}
}
}
nextChar := byte(0)
if len(text) > 1 {
nextChar = text[1]
}
if smartQuoteHelper(out, previousChar, nextChar, 's', &r.inSingleQuote, false) {
return 0
}
out.WriteByte(text[0])
return 0
}
func (r *SPRenderer) smartParens(out *bytes.Buffer, previousChar byte, text []byte) int {
if len(text) >= 3 {
t1 := tolower(text[1])
t2 := tolower(text[2])
if t1 == 'c' && t2 == ')' {
out.WriteString("&copy;")
return 2
}
if t1 == 'r' && t2 == ')' {
out.WriteString("&reg;")
return 2
}
if len(text) >= 4 && t1 == 't' && t2 == 'm' && text[3] == ')' {
out.WriteString("&trade;")
return 3
}
}
out.WriteByte(text[0])
return 0
}
func (r *SPRenderer) smartDash(out *bytes.Buffer, previousChar byte, text []byte) int {
if len(text) >= 2 {
if text[1] == '-' {
out.WriteString("&mdash;")
return 1
}
if wordBoundary(previousChar) && wordBoundary(text[1]) {
out.WriteString("&ndash;")
return 0
}
}
out.WriteByte(text[0])
return 0
}
func (r *SPRenderer) smartDashLatex(out *bytes.Buffer, previousChar byte, text []byte) int {
if len(text) >= 3 && text[1] == '-' && text[2] == '-' {
out.WriteString("&mdash;")
return 2
}
if len(text) >= 2 && text[1] == '-' {
out.WriteString("&ndash;")
return 1
}
out.WriteByte(text[0])
return 0
}
func (r *SPRenderer) smartAmpVariant(out *bytes.Buffer, previousChar byte, text []byte, quote byte, addNBSP bool) int {
if bytes.HasPrefix(text, []byte("&quot;")) {
nextChar := byte(0)
if len(text) >= 7 {
nextChar = text[6]
}
if smartQuoteHelper(out, previousChar, nextChar, quote, &r.inDoubleQuote, addNBSP) {
return 5
}
}
if bytes.HasPrefix(text, []byte("&#0;")) {
return 3
}
out.WriteByte('&')
return 0
}
func (r *SPRenderer) smartAmp(angledQuotes, addNBSP bool) func(*bytes.Buffer, byte, []byte) int {
var quote byte = 'd'
if angledQuotes {
quote = 'a'
}
return func(out *bytes.Buffer, previousChar byte, text []byte) int {
return r.smartAmpVariant(out, previousChar, text, quote, addNBSP)
}
}
func (r *SPRenderer) smartPeriod(out *bytes.Buffer, previousChar byte, text []byte) int {
if len(text) >= 3 && text[1] == '.' && text[2] == '.' {
out.WriteString("&hellip;")
return 2
}
if len(text) >= 5 && text[1] == ' ' && text[2] == '.' && text[3] == ' ' && text[4] == '.' {
out.WriteString("&hellip;")
return 4
}
out.WriteByte(text[0])
return 0
}
func (r *SPRenderer) smartBacktick(out *bytes.Buffer, previousChar byte, text []byte) int {
if len(text) >= 2 && text[1] == '`' {
nextChar := byte(0)
if len(text) >= 3 {
nextChar = text[2]
}
if smartQuoteHelper(out, previousChar, nextChar, 'd', &r.inDoubleQuote, false) {
return 1
}
}
out.WriteByte(text[0])
return 0
}
func (r *SPRenderer) smartNumberGeneric(out *bytes.Buffer, previousChar byte, text []byte) int {
if wordBoundary(previousChar) && previousChar != '/' && len(text) >= 3 {
// is it of the form digits/digits(word boundary)?, i.e., \d+/\d+\b
// note: check for regular slash (/) or fraction slash (, 0x2044, or 0xe2 81 84 in utf-8)
// and avoid changing dates like 1/23/2005 into fractions.
numEnd := 0
for len(text) > numEnd && isdigit(text[numEnd]) {
numEnd++
}
if numEnd == 0 {
out.WriteByte(text[0])
return 0
}
denStart := numEnd + 1
if len(text) > numEnd+3 && text[numEnd] == 0xe2 && text[numEnd+1] == 0x81 && text[numEnd+2] == 0x84 {
denStart = numEnd + 3
} else if len(text) < numEnd+2 || text[numEnd] != '/' {
out.WriteByte(text[0])
return 0
}
denEnd := denStart
for len(text) > denEnd && isdigit(text[denEnd]) {
denEnd++
}
if denEnd == denStart {
out.WriteByte(text[0])
return 0
}
if len(text) == denEnd || wordBoundary(text[denEnd]) && text[denEnd] != '/' {
out.WriteString("<sup>")
out.Write(text[:numEnd])
out.WriteString("</sup>&frasl;<sub>")
out.Write(text[denStart:denEnd])
out.WriteString("</sub>")
return denEnd - 1
}
}
out.WriteByte(text[0])
return 0
}
func (r *SPRenderer) smartNumber(out *bytes.Buffer, previousChar byte, text []byte) int {
if wordBoundary(previousChar) && previousChar != '/' && len(text) >= 3 {
if text[0] == '1' && text[1] == '/' && text[2] == '2' {
if len(text) < 4 || wordBoundary(text[3]) && text[3] != '/' {
out.WriteString("&frac12;")
return 2
}
}
if text[0] == '1' && text[1] == '/' && text[2] == '4' {
if len(text) < 4 || wordBoundary(text[3]) && text[3] != '/' || (len(text) >= 5 && tolower(text[3]) == 't' && tolower(text[4]) == 'h') {
out.WriteString("&frac14;")
return 2
}
}
if text[0] == '3' && text[1] == '/' && text[2] == '4' {
if len(text) < 4 || wordBoundary(text[3]) && text[3] != '/' || (len(text) >= 6 && tolower(text[3]) == 't' && tolower(text[4]) == 'h' && tolower(text[5]) == 's') {
out.WriteString("&frac34;")
return 2
}
}
}
out.WriteByte(text[0])
return 0
}
func (r *SPRenderer) smartDoubleQuoteVariant(out *bytes.Buffer, previousChar byte, text []byte, quote byte) int {
nextChar := byte(0)
if len(text) > 1 {
nextChar = text[1]
}
if !smartQuoteHelper(out, previousChar, nextChar, quote, &r.inDoubleQuote, false) {
out.WriteString("&quot;")
}
return 0
}
func (r *SPRenderer) smartDoubleQuote(out *bytes.Buffer, previousChar byte, text []byte) int {
return r.smartDoubleQuoteVariant(out, previousChar, text, 'd')
}
func (r *SPRenderer) smartAngledDoubleQuote(out *bytes.Buffer, previousChar byte, text []byte) int {
return r.smartDoubleQuoteVariant(out, previousChar, text, 'a')
}
func (r *SPRenderer) smartLeftAngle(out *bytes.Buffer, previousChar byte, text []byte) int {
i := 0
for i < len(text) && text[i] != '>' {
i++
}
out.Write(text[:i+1])
return i
}
type smartCallback func(out *bytes.Buffer, previousChar byte, text []byte) int
// NewSmartypantsRenderer constructs a Smartypants renderer object.
func NewSmartypantsRenderer(flags HTMLFlags) *SPRenderer {
var (
r SPRenderer
smartAmpAngled = r.smartAmp(true, false)
smartAmpAngledNBSP = r.smartAmp(true, true)
smartAmpRegular = r.smartAmp(false, false)
smartAmpRegularNBSP = r.smartAmp(false, true)
addNBSP = flags&SmartypantsQuotesNBSP != 0
)
if flags&SmartypantsAngledQuotes == 0 {
r.callbacks['"'] = r.smartDoubleQuote
if !addNBSP {
r.callbacks['&'] = smartAmpRegular
} else {
r.callbacks['&'] = smartAmpRegularNBSP
}
} else {
r.callbacks['"'] = r.smartAngledDoubleQuote
if !addNBSP {
r.callbacks['&'] = smartAmpAngled
} else {
r.callbacks['&'] = smartAmpAngledNBSP
}
}
r.callbacks['\''] = r.smartSingleQuote
r.callbacks['('] = r.smartParens
if flags&SmartypantsDashes != 0 {
if flags&SmartypantsLatexDashes == 0 {
r.callbacks['-'] = r.smartDash
} else {
r.callbacks['-'] = r.smartDashLatex
}
}
r.callbacks['.'] = r.smartPeriod
if flags&SmartypantsFractions == 0 {
r.callbacks['1'] = r.smartNumber
r.callbacks['3'] = r.smartNumber
} else {
for ch := '1'; ch <= '9'; ch++ {
r.callbacks[ch] = r.smartNumberGeneric
}
}
r.callbacks['<'] = r.smartLeftAngle
r.callbacks['`'] = r.smartBacktick
return &r
}
// Process is the entry point of the Smartypants renderer.
func (r *SPRenderer) Process(w io.Writer, text []byte) {
mark := 0
for i := 0; i < len(text); i++ {
if action := r.callbacks[text[i]]; action != nil {
if i > mark {
w.Write(text[mark:i])
}
previousChar := byte(0)
if i > 0 {
previousChar = text[i-1]
}
var tmp bytes.Buffer
i += action(&tmp, previousChar, text[i:])
w.Write(tmp.Bytes())
mark = i + 1
}
}
if mark < len(text) {
w.Write(text[mark:])
}
}