mirror of https://github.com/go-gitea/gitea
100 lines
2.4 KiB
Go
100 lines
2.4 KiB
Go
// Copyright 2022 The Gitea Authors. All rights reserved.
|
|
// Use of this source code is governed by a MIT-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package math
|
|
|
|
import (
|
|
"bytes"
|
|
|
|
"github.com/yuin/goldmark/ast"
|
|
"github.com/yuin/goldmark/parser"
|
|
"github.com/yuin/goldmark/text"
|
|
)
|
|
|
|
type inlineParser struct {
|
|
start []byte
|
|
end []byte
|
|
}
|
|
|
|
var defaultInlineDollarParser = &inlineParser{
|
|
start: []byte{'$'},
|
|
end: []byte{'$'},
|
|
}
|
|
|
|
// NewInlineDollarParser returns a new inline parser
|
|
func NewInlineDollarParser() parser.InlineParser {
|
|
return defaultInlineDollarParser
|
|
}
|
|
|
|
var defaultInlineBracketParser = &inlineParser{
|
|
start: []byte{'\\', '('},
|
|
end: []byte{'\\', ')'},
|
|
}
|
|
|
|
// NewInlineDollarParser returns a new inline parser
|
|
func NewInlineBracketParser() parser.InlineParser {
|
|
return defaultInlineBracketParser
|
|
}
|
|
|
|
// Trigger triggers this parser on $
|
|
func (parser *inlineParser) Trigger() []byte {
|
|
return parser.start[0:1]
|
|
}
|
|
|
|
func isAlphanumeric(b byte) bool {
|
|
// Github only cares about 0-9A-Za-z
|
|
return (b >= '0' && b <= '9') || (b >= 'A' && b <= 'Z') || (b >= 'a' && b <= 'z')
|
|
}
|
|
|
|
// Parse parses the current line and returns a result of parsing.
|
|
func (parser *inlineParser) Parse(parent ast.Node, block text.Reader, pc parser.Context) ast.Node {
|
|
line, _ := block.PeekLine()
|
|
opener := bytes.Index(line, parser.start)
|
|
if opener < 0 {
|
|
return nil
|
|
}
|
|
if opener != 0 && isAlphanumeric(line[opener-1]) {
|
|
return nil
|
|
}
|
|
|
|
opener += len(parser.start)
|
|
ender := bytes.Index(line[opener:], parser.end)
|
|
if ender < 0 {
|
|
return nil
|
|
}
|
|
if len(line) > opener+ender+len(parser.end) && isAlphanumeric(line[opener+ender+len(parser.end)]) {
|
|
return nil
|
|
}
|
|
|
|
block.Advance(opener)
|
|
_, pos := block.Position()
|
|
node := NewInline()
|
|
segment := pos.WithStop(pos.Start + ender)
|
|
node.AppendChild(node, ast.NewRawTextSegment(segment))
|
|
block.Advance(ender + len(parser.end))
|
|
|
|
trimBlock(node, block)
|
|
return node
|
|
}
|
|
|
|
func trimBlock(node *Inline, block text.Reader) {
|
|
if node.IsBlank(block.Source()) {
|
|
return
|
|
}
|
|
|
|
// trim first space and last space
|
|
first := node.FirstChild().(*ast.Text)
|
|
if !(!first.Segment.IsEmpty() && block.Source()[first.Segment.Start] == ' ') {
|
|
return
|
|
}
|
|
|
|
last := node.LastChild().(*ast.Text)
|
|
if !(!last.Segment.IsEmpty() && block.Source()[last.Segment.Stop-1] == ' ') {
|
|
return
|
|
}
|
|
|
|
first.Segment = first.Segment.WithStart(first.Segment.Start + 1)
|
|
last.Segment = last.Segment.WithStop(last.Segment.Stop - 1)
|
|
}
|