f88b58be3f
- Currently the parser will look for `\[` and `$$` to detect when Latex code starts, it will look for `\]` and `$$` respectively in order to determine the end of the code. However if no end is found the parser assumes the rest of the input is part of the Latex code. - Adjust the parser's behavior to not allow the case to assume the rest of the input is part of the Latex code and requires in order to determine if some input is Latex code that the end sequence is also specified. - Example: `\[hello]` would no longer be detected as Latex code with this patch. - Added unit tests. - Resolves https://codeberg.org/forgejo/forgejo/issues/1817 (cherry picked from commit452aef1bb1) (cherry picked from commit8a857c24b0) (cherry picked from commitacd1456db9) (cherry picked from commit6523b45073) (cherry picked from commite2e1a8afe7) (cherry picked from commita46ef652eb) (cherry picked from commit54d5a8c073) (cherry picked from commit4a88dc6416)
119 lines
3.3 KiB
Go
119 lines
3.3 KiB
Go
// Copyright 2022 The Gitea Authors. All rights reserved.
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// SPDX-License-Identifier: MIT
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package math
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import (
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"bytes"
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"github.com/yuin/goldmark/ast"
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"github.com/yuin/goldmark/parser"
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"github.com/yuin/goldmark/text"
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"github.com/yuin/goldmark/util"
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)
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type blockParser struct {
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parseDollars bool
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}
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// NewBlockParser creates a new math BlockParser
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func NewBlockParser(parseDollarBlocks bool) parser.BlockParser {
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return &blockParser{
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parseDollars: parseDollarBlocks,
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}
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}
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// Open parses the current line and returns a result of parsing.
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func (b *blockParser) Open(parent ast.Node, reader text.Reader, pc parser.Context) (ast.Node, parser.State) {
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line, segment := reader.PeekLine()
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pos := pc.BlockOffset()
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if pos == -1 || len(line[pos:]) < 2 {
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return nil, parser.NoChildren
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}
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dollars := false
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if b.parseDollars && line[pos] == '$' && line[pos+1] == '$' {
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dollars = true
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} else if line[pos] != '\\' || line[pos+1] != '[' {
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return nil, parser.NoChildren
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}
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node := NewBlock(dollars, pos)
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// Now we need to check if the ending block is on the segment...
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endBytes := []byte{'\\', ']'}
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if dollars {
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endBytes = []byte{'$', '$'}
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}
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idx := bytes.Index(line[pos+2:], endBytes)
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if idx >= 0 {
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segment.Stop = segment.Start + idx + 2
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reader.Advance(segment.Len() - 1)
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segment.Start += 2
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node.Lines().Append(segment)
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node.Closed = true
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return node, parser.Close | parser.NoChildren
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}
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return nil, parser.NoChildren
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}
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// Continue parses the current line and returns a result of parsing.
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func (b *blockParser) Continue(node ast.Node, reader text.Reader, pc parser.Context) parser.State {
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block := node.(*Block)
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if block.Closed {
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return parser.Close
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}
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line, segment := reader.PeekLine()
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w, pos := util.IndentWidth(line, 0)
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if w < 4 {
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if block.Dollars {
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i := pos
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for ; i < len(line) && line[i] == '$'; i++ {
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}
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length := i - pos
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if length >= 2 && util.IsBlank(line[i:]) {
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reader.Advance(segment.Stop - segment.Start - segment.Padding)
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block.Closed = true
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return parser.Close
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}
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} else if len(line[pos:]) > 1 && line[pos] == '\\' && line[pos+1] == ']' && util.IsBlank(line[pos+2:]) {
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reader.Advance(segment.Stop - segment.Start - segment.Padding)
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block.Closed = true
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return parser.Close
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}
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}
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pos, padding := util.IndentPosition(line, 0, block.Indent)
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seg := text.NewSegmentPadding(segment.Start+pos, segment.Stop, padding)
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node.Lines().Append(seg)
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reader.AdvanceAndSetPadding(segment.Stop-segment.Start-pos-1, padding)
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return parser.Continue | parser.NoChildren
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}
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// Close will be called when the parser returns Close.
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func (b *blockParser) Close(node ast.Node, reader text.Reader, pc parser.Context) {
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// noop
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}
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// CanInterruptParagraph returns true if the parser can interrupt paragraphs,
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// otherwise false.
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func (b *blockParser) CanInterruptParagraph() bool {
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return true
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}
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// CanAcceptIndentedLine returns true if the parser can open new node when
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// the given line is being indented more than 3 spaces.
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func (b *blockParser) CanAcceptIndentedLine() bool {
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return false
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}
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// Trigger returns a list of characters that triggers Parse method of
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// this parser.
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// If Trigger returns a nil, Open will be called with any lines.
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//
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// We leave this as nil as our parse method is quick enough
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func (b *blockParser) Trigger() []byte {
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return nil
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}
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