gitea/vendor/github.com/yuin/goldmark/extension/typographer.go
zeripath 27757714d0 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>
2019-12-31 03:53:28 +02:00

246 lines
6.6 KiB
Go

package extension
import (
"github.com/yuin/goldmark"
gast "github.com/yuin/goldmark/ast"
"github.com/yuin/goldmark/parser"
"github.com/yuin/goldmark/text"
"github.com/yuin/goldmark/util"
)
// TypographicPunctuation is a key of the punctuations that can be replaced with
// typographic entities.
type TypographicPunctuation int
const (
// LeftSingleQuote is '
LeftSingleQuote TypographicPunctuation = iota + 1
// RightSingleQuote is '
RightSingleQuote
// LeftDoubleQuote is "
LeftDoubleQuote
// RightDoubleQuote is "
RightDoubleQuote
// EnDash is --
EnDash
// EmDash is ---
EmDash
// Ellipsis is ...
Ellipsis
// LeftAngleQuote is <<
LeftAngleQuote
// RightAngleQuote is >>
RightAngleQuote
typographicPunctuationMax
)
// An TypographerConfig struct is a data structure that holds configuration of the
// Typographer extension.
type TypographerConfig struct {
Substitutions [][]byte
}
func newDefaultSubstitutions() [][]byte {
replacements := make([][]byte, typographicPunctuationMax)
replacements[LeftSingleQuote] = []byte("&lsquo;")
replacements[RightSingleQuote] = []byte("&rsquo;")
replacements[LeftDoubleQuote] = []byte("&ldquo;")
replacements[RightDoubleQuote] = []byte("&rdquo;")
replacements[EnDash] = []byte("&ndash;")
replacements[EmDash] = []byte("&mdash;")
replacements[Ellipsis] = []byte("&hellip;")
replacements[LeftAngleQuote] = []byte("&laquo;")
replacements[RightAngleQuote] = []byte("&raquo;")
return replacements
}
// SetOption implements SetOptioner.
func (b *TypographerConfig) SetOption(name parser.OptionName, value interface{}) {
switch name {
case optTypographicSubstitutions:
b.Substitutions = value.([][]byte)
}
}
// A TypographerOption interface sets options for the TypographerParser.
type TypographerOption interface {
parser.Option
SetTypographerOption(*TypographerConfig)
}
const optTypographicSubstitutions parser.OptionName = "TypographicSubstitutions"
// TypographicSubstitutions is a list of the substitutions for the Typographer extension.
type TypographicSubstitutions map[TypographicPunctuation][]byte
type withTypographicSubstitutions struct {
value [][]byte
}
func (o *withTypographicSubstitutions) SetParserOption(c *parser.Config) {
c.Options[optTypographicSubstitutions] = o.value
}
func (o *withTypographicSubstitutions) SetTypographerOption(p *TypographerConfig) {
p.Substitutions = o.value
}
// WithTypographicSubstitutions is a functional otpion that specify replacement text
// for punctuations.
func WithTypographicSubstitutions(values map[TypographicPunctuation][]byte) TypographerOption {
replacements := newDefaultSubstitutions()
for k, v := range values {
replacements[k] = v
}
return &withTypographicSubstitutions{replacements}
}
type typographerDelimiterProcessor struct {
}
func (p *typographerDelimiterProcessor) IsDelimiter(b byte) bool {
return b == '\'' || b == '"'
}
func (p *typographerDelimiterProcessor) CanOpenCloser(opener, closer *parser.Delimiter) bool {
return opener.Char == closer.Char
}
func (p *typographerDelimiterProcessor) OnMatch(consumes int) gast.Node {
return nil
}
var defaultTypographerDelimiterProcessor = &typographerDelimiterProcessor{}
type typographerParser struct {
TypographerConfig
}
// NewTypographerParser return a new InlineParser that parses
// typographer expressions.
func NewTypographerParser(opts ...TypographerOption) parser.InlineParser {
p := &typographerParser{
TypographerConfig: TypographerConfig{
Substitutions: newDefaultSubstitutions(),
},
}
for _, o := range opts {
o.SetTypographerOption(&p.TypographerConfig)
}
return p
}
func (s *typographerParser) Trigger() []byte {
return []byte{'\'', '"', '-', '.', '<', '>'}
}
func (s *typographerParser) Parse(parent gast.Node, block text.Reader, pc parser.Context) gast.Node {
before := block.PrecendingCharacter()
line, _ := block.PeekLine()
c := line[0]
if len(line) > 2 {
if c == '-' {
if s.Substitutions[EmDash] != nil && line[1] == '-' && line[2] == '-' { // ---
node := gast.NewString(s.Substitutions[EmDash])
node.SetCode(true)
block.Advance(3)
return node
}
} else if c == '.' {
if s.Substitutions[Ellipsis] != nil && line[1] == '.' && line[2] == '.' { // ...
node := gast.NewString(s.Substitutions[Ellipsis])
node.SetCode(true)
block.Advance(3)
return node
}
return nil
}
}
if len(line) > 1 {
if c == '<' {
if s.Substitutions[LeftAngleQuote] != nil && line[1] == '<' { // <<
node := gast.NewString(s.Substitutions[LeftAngleQuote])
node.SetCode(true)
block.Advance(2)
return node
}
return nil
} else if c == '>' {
if s.Substitutions[RightAngleQuote] != nil && line[1] == '>' { // >>
node := gast.NewString(s.Substitutions[RightAngleQuote])
node.SetCode(true)
block.Advance(2)
return node
}
return nil
} else if s.Substitutions[EnDash] != nil && c == '-' && line[1] == '-' { // --
node := gast.NewString(s.Substitutions[EnDash])
node.SetCode(true)
block.Advance(2)
return node
}
}
if c == '\'' || c == '"' {
d := parser.ScanDelimiter(line, before, 1, defaultTypographerDelimiterProcessor)
if d == nil {
return nil
}
if c == '\'' {
if s.Substitutions[LeftSingleQuote] != nil && d.CanOpen && !d.CanClose {
node := gast.NewString(s.Substitutions[LeftSingleQuote])
node.SetCode(true)
block.Advance(1)
return node
}
if s.Substitutions[RightSingleQuote] != nil && d.CanClose && !d.CanOpen {
node := gast.NewString(s.Substitutions[RightSingleQuote])
node.SetCode(true)
block.Advance(1)
return node
}
}
if c == '"' {
if s.Substitutions[LeftDoubleQuote] != nil && d.CanOpen && !d.CanClose {
node := gast.NewString(s.Substitutions[LeftDoubleQuote])
node.SetCode(true)
block.Advance(1)
return node
}
if s.Substitutions[RightDoubleQuote] != nil && d.CanClose && !d.CanOpen {
node := gast.NewString(s.Substitutions[RightDoubleQuote])
node.SetCode(true)
block.Advance(1)
return node
}
}
}
return nil
}
func (s *typographerParser) CloseBlock(parent gast.Node, pc parser.Context) {
// nothing to do
}
type typographer struct {
options []TypographerOption
}
// Typographer is an extension that repalace punctuations with typographic entities.
var Typographer = &typographer{}
// NewTypographer returns a new Entender that repalace punctuations with typographic entities.
func NewTypographer(opts ...TypographerOption) goldmark.Extender {
return &typographer{
options: opts,
}
}
func (e *typographer) Extend(m goldmark.Markdown) {
m.Parser().AddOptions(parser.WithInlineParsers(
util.Prioritized(NewTypographerParser(e.options...), 9999),
))
}