forgejo-federation/vendor/github.com/yuin/goldmark/parser/attribute.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

319 lines
6.6 KiB
Go
Vendored

package parser
import (
"bytes"
"io"
"strconv"
"github.com/yuin/goldmark/text"
"github.com/yuin/goldmark/util"
)
var attrNameID = []byte("id")
var attrNameClass = []byte("class")
// An Attribute is an attribute of the markdown elements
type Attribute struct {
Name []byte
Value interface{}
}
// An Attributes is a collection of attributes.
type Attributes []Attribute
// Find returns a (value, true) if an attribute correspond with given name is found, otherwise (nil, false).
func (as Attributes) Find(name []byte) (interface{}, bool) {
for _, a := range as {
if bytes.Equal(a.Name, name) {
return a.Value, true
}
}
return nil, false
}
func (as Attributes) findUpdate(name []byte, cb func(v interface{}) interface{}) bool {
for i, a := range as {
if bytes.Equal(a.Name, name) {
as[i].Value = cb(a.Value)
return true
}
}
return false
}
// ParseAttributes parses attributes into a map.
// ParseAttributes returns a parsed attributes and true if could parse
// attributes, otherwise nil and false.
func ParseAttributes(reader text.Reader) (Attributes, bool) {
savedLine, savedPosition := reader.Position()
reader.SkipSpaces()
if reader.Peek() != '{' {
reader.SetPosition(savedLine, savedPosition)
return nil, false
}
reader.Advance(1)
attrs := Attributes{}
for {
if reader.Peek() == '}' {
reader.Advance(1)
return attrs, true
}
attr, ok := parseAttribute(reader)
if !ok {
reader.SetPosition(savedLine, savedPosition)
return nil, false
}
if bytes.Equal(attr.Name, attrNameClass) {
if !attrs.findUpdate(attrNameClass, func(v interface{}) interface{} {
ret := make([]byte, 0, len(v.([]byte))+1+len(attr.Value.([]byte)))
ret = append(ret, v.([]byte)...)
return append(append(ret, ' '), attr.Value.([]byte)...)
}) {
attrs = append(attrs, attr)
}
} else {
attrs = append(attrs, attr)
}
reader.SkipSpaces()
if reader.Peek() == ',' {
reader.Advance(1)
reader.SkipSpaces()
}
}
}
func parseAttribute(reader text.Reader) (Attribute, bool) {
reader.SkipSpaces()
c := reader.Peek()
if c == '#' || c == '.' {
reader.Advance(1)
line, _ := reader.PeekLine()
i := 0
for ; i < len(line) && !util.IsSpace(line[i]) && (!util.IsPunct(line[i]) || line[i] == '_' || line[i] == '-'); i++ {
}
name := attrNameClass
if c == '#' {
name = attrNameID
}
reader.Advance(i)
return Attribute{Name: name, Value: line[0:i]}, true
}
line, _ := reader.PeekLine()
if len(line) == 0 {
return Attribute{}, false
}
c = line[0]
if !((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
c == '_' || c == ':') {
return Attribute{}, false
}
i := 0
for ; i < len(line); i++ {
c = line[i]
if !((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
(c >= '0' && c <= '9') ||
c == '_' || c == ':' || c == '.' || c == '-') {
break
}
}
name := line[:i]
reader.Advance(i)
reader.SkipSpaces()
c = reader.Peek()
if c != '=' {
return Attribute{}, false
}
reader.Advance(1)
reader.SkipSpaces()
value, ok := parseAttributeValue(reader)
if !ok {
return Attribute{}, false
}
return Attribute{Name: name, Value: value}, true
}
func parseAttributeValue(reader text.Reader) (interface{}, bool) {
reader.SkipSpaces()
c := reader.Peek()
var value interface{}
ok := false
switch c {
case text.EOF:
return Attribute{}, false
case '{':
value, ok = ParseAttributes(reader)
case '[':
value, ok = parseAttributeArray(reader)
case '"':
value, ok = parseAttributeString(reader)
default:
if c == '-' || c == '+' || util.IsNumeric(c) {
value, ok = parseAttributeNumber(reader)
} else {
value, ok = parseAttributeOthers(reader)
}
}
if !ok {
return nil, false
}
return value, true
}
func parseAttributeArray(reader text.Reader) ([]interface{}, bool) {
reader.Advance(1) // skip [
ret := []interface{}{}
for i := 0; ; i++ {
c := reader.Peek()
comma := false
if i != 0 && c == ',' {
reader.Advance(1)
comma = true
}
if c == ']' {
if !comma {
reader.Advance(1)
return ret, true
}
return nil, false
}
reader.SkipSpaces()
value, ok := parseAttributeValue(reader)
if !ok {
return nil, false
}
ret = append(ret, value)
reader.SkipSpaces()
}
}
func parseAttributeString(reader text.Reader) ([]byte, bool) {
reader.Advance(1) // skip "
line, _ := reader.PeekLine()
i := 0
l := len(line)
var buf bytes.Buffer
for i < l {
c := line[i]
if c == '\\' && i != l-1 {
n := line[i+1]
switch n {
case '"', '/', '\\':
buf.WriteByte(n)
i += 2
case 'b':
buf.WriteString("\b")
i += 2
case 'f':
buf.WriteString("\f")
i += 2
case 'n':
buf.WriteString("\n")
i += 2
case 'r':
buf.WriteString("\r")
i += 2
case 't':
buf.WriteString("\t")
i += 2
default:
buf.WriteByte('\\')
i++
}
continue
}
if c == '"' {
reader.Advance(i + 1)
return buf.Bytes(), true
}
buf.WriteByte(c)
i++
}
return nil, false
}
func scanAttributeDecimal(reader text.Reader, w io.ByteWriter) {
for {
c := reader.Peek()
if util.IsNumeric(c) {
w.WriteByte(c)
} else {
return
}
reader.Advance(1)
}
}
func parseAttributeNumber(reader text.Reader) (float64, bool) {
sign := 1
c := reader.Peek()
if c == '-' {
sign = -1
reader.Advance(1)
} else if c == '+' {
reader.Advance(1)
}
var buf bytes.Buffer
if !util.IsNumeric(reader.Peek()) {
return 0, false
}
scanAttributeDecimal(reader, &buf)
if buf.Len() == 0 {
return 0, false
}
c = reader.Peek()
if c == '.' {
buf.WriteByte(c)
reader.Advance(1)
scanAttributeDecimal(reader, &buf)
}
c = reader.Peek()
if c == 'e' || c == 'E' {
buf.WriteByte(c)
reader.Advance(1)
c = reader.Peek()
if c == '-' || c == '+' {
buf.WriteByte(c)
reader.Advance(1)
}
scanAttributeDecimal(reader, &buf)
}
f, err := strconv.ParseFloat(buf.String(), 10)
if err != nil {
return 0, false
}
return float64(sign) * f, true
}
var bytesTrue = []byte("true")
var bytesFalse = []byte("false")
var bytesNull = []byte("null")
func parseAttributeOthers(reader text.Reader) (interface{}, bool) {
line, _ := reader.PeekLine()
c := line[0]
if !((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
c == '_' || c == ':') {
return nil, false
}
i := 0
for ; i < len(line); i++ {
c := line[i]
if !((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
(c >= '0' && c <= '9') ||
c == '_' || c == ':' || c == '.' || c == '-') {
break
}
}
value := line[:i]
reader.Advance(i)
if bytes.Equal(value, bytesTrue) {
return true, true
}
if bytes.Equal(value, bytesFalse) {
return false, true
}
if bytes.Equal(value, bytesNull) {
return nil, true
}
return value, true
}