feat: implement gomark parsers

plugin/gomark/ast/block.go

@@ -1,6 +1,7 @@
 package ast
 
 type BaseBlock struct {
+	Node
 }
 
 type LineBreak struct {
@@ -50,3 +51,28 @@ var NodeTypeHeading = NewNodeType("Heading")
 func (*Heading) Type() NodeType {
 	return NodeTypeHeading
 }
+
+type HorizontalRule struct {
+	BaseBlock
+
+	// Symbol is "*" or "-" or "_".
+	Symbol string
+}
+
+var NodeTypeHorizontalRule = NewNodeType("HorizontalRule")
+
+func (*HorizontalRule) Type() NodeType {
+	return NodeTypeHorizontalRule
+}
+
+type Blockquote struct {
+	BaseBlock
+
+	Children []Node
+}
+
+var NodeTypeBlockquote = NewNodeType("Blockquote")
+
+func (*Blockquote) Type() NodeType {
+	return NodeTypeBlockquote
+}

plugin/gomark/ast/inline.go

@@ -1,6 +1,8 @@
 package ast
 
-type BaseInline struct{}
+type BaseInline struct {
+	Node
+}
 
 type Text struct {
 	BaseInline
@@ -28,6 +30,34 @@ func (*Bold) Type() NodeType {
 	return NodeTypeBold
 }
 
+type Italic struct {
+	BaseInline
+
+	// Symbol is "*" or "_"
+	Symbol  string
+	Content string
+}
+
+var NodeTypeItalic = NewNodeType("Italic")
+
+func (*Italic) Type() NodeType {
+	return NodeTypeItalic
+}
+
+type BoldItalic struct {
+	BaseInline
+
+	// Symbol is "*" or "_"
+	Symbol  string
+	Content string
+}
+
+var NodeTypeBoldItalic = NewNodeType("BoldItalic")
+
+func (*BoldItalic) Type() NodeType {
+	return NodeTypeBoldItalic
+}
+
 type Code struct {
 	BaseInline
 
@@ -66,28 +96,26 @@ func (*Link) Type() NodeType {
 	return NodeTypeLink
 }
 
-type Italic struct {
+type Tag struct {
 	BaseInline
 
-	// Symbol is "*" or "_"
-	Symbol  string
 	Content string
 }
 
-var NodeTypeItalic = NewNodeType("Italic")
+var NodeTypeTag = NewNodeType("Tag")
 
-func (*Italic) Type() NodeType {
-	return NodeTypeItalic
+func (*Tag) Type() NodeType {
+	return NodeTypeTag
 }
 
-type Tag struct {
+type Strikethrough struct {
 	BaseInline
 
 	Content string
 }
 
-var NodeTypeTag = NewNodeType("Tag")
+var NodeTypeStrikethrough = NewNodeType("Strikethrough")
 
-func (*Tag) Type() NodeType {
-	return NodeTypeTag
+func (*Strikethrough) Type() NodeType {
+	return NodeTypeStrikethrough
 }

plugin/gomark/parser/blockquote.go

@@ -0,0 +1,47 @@
+package parser
+
+import (
+	"github.com/usememos/memos/plugin/gomark/ast"
+	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+)
+
+type BlockquoteParser struct{}
+
+func NewBlockquoteParser() *BlockquoteParser {
+	return &BlockquoteParser{}
+}
+
+func (*BlockquoteParser) Match(tokens []*tokenizer.Token) (int, bool) {
+	if len(tokens) < 4 {
+		return 0, false
+	}
+	if tokens[0].Type != tokenizer.GreaterThan || tokens[1].Type != tokenizer.Space {
+		return 0, false
+	}
+
+	contentTokens := []*tokenizer.Token{}
+	for _, token := range tokens[2:] {
+		if token.Type == tokenizer.Newline {
+			break
+		}
+		contentTokens = append(contentTokens, token)
+	}
+	if len(contentTokens) == 0 {
+		return 0, false
+	}
+
+	return len(contentTokens) + 2, true
+}
+
+func (p *BlockquoteParser) Parse(tokens []*tokenizer.Token) ast.Node {
+	size, ok := p.Match(tokens)
+	if size == 0 || !ok {
+		return nil
+	}
+
+	contentTokens := tokens[2:size]
+	children := ParseInline(contentTokens)
+	return &ast.Blockquote{
+		Children: children,
+	}
+}

plugin/gomark/parser/blockquote_test.go

@@ -0,0 +1,47 @@
+package parser
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/usememos/memos/plugin/gomark/ast"
+	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+)
+
+func TestBlockquoteParser(t *testing.T) {
+	tests := []struct {
+		text       string
+		blockquote ast.Node
+	}{
+		{
+			text: "> Hello world",
+			blockquote: &ast.Blockquote{
+				Children: []ast.Node{
+					&ast.Text{
+						Content: "Hello world",
+					},
+				},
+			},
+		},
+		{
+			text: "> Hello\nworld",
+			blockquote: &ast.Blockquote{
+				Children: []ast.Node{
+					&ast.Text{
+						Content: "Hello",
+					},
+				},
+			},
+		},
+		{
+			text:       ">Hello\nworld",
+			blockquote: nil,
+		},
+	}
+
+	for _, test := range tests {
+		tokens := tokenizer.Tokenize(test.text)
+		require.Equal(t, test.blockquote, NewBlockquoteParser().Parse(tokens))
+	}
+}

plugin/gomark/parser/bold.go

@@ -7,10 +7,8 @@ import (
 
 type BoldParser struct{}
 
-var defaultBoldParser = &BoldParser{}
-
 func NewBoldParser() InlineParser {
-	return defaultBoldParser
+	return &BoldParser{}
 }
 
 func (*BoldParser) Match(tokens []*tokenizer.Token) (int, bool) {
@@ -23,7 +21,7 @@ func (*BoldParser) Match(tokens []*tokenizer.Token) (int, bool) {
 		return 0, false
 	}
 	prefixTokenType := prefixTokens[0].Type
-	if prefixTokenType != tokenizer.Star && prefixTokenType != tokenizer.Underline {
+	if prefixTokenType != tokenizer.Asterisk && prefixTokenType != tokenizer.Underline {
 		return 0, false
 	}
 

plugin/gomark/parser/bold_italic.go

@@ -0,0 +1,58 @@
+package parser
+
+import (
+	"github.com/usememos/memos/plugin/gomark/ast"
+	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+)
+
+type BoldItalicParser struct{}
+
+func NewBoldItalicParser() InlineParser {
+	return &BoldItalicParser{}
+}
+
+func (*BoldItalicParser) Match(tokens []*tokenizer.Token) (int, bool) {
+	if len(tokens) < 7 {
+		return 0, false
+	}
+
+	prefixTokens := tokens[:3]
+	if prefixTokens[0].Type != prefixTokens[1].Type || prefixTokens[0].Type != prefixTokens[2].Type || prefixTokens[1].Type != prefixTokens[2].Type {
+		return 0, false
+	}
+	prefixTokenType := prefixTokens[0].Type
+	if prefixTokenType != tokenizer.Asterisk && prefixTokenType != tokenizer.Underline {
+		return 0, false
+	}
+
+	cursor, matched := 3, false
+	for ; cursor < len(tokens)-2; cursor++ {
+		token, nextToken, endToken := tokens[cursor], tokens[cursor+1], tokens[cursor+2]
+		if token.Type == tokenizer.Newline || nextToken.Type == tokenizer.Newline || endToken.Type == tokenizer.Newline {
+			return 0, false
+		}
+		if token.Type == prefixTokenType && nextToken.Type == prefixTokenType && endToken.Type == prefixTokenType {
+			matched = true
+			break
+		}
+	}
+	if !matched {
+		return 0, false
+	}
+
+	return cursor + 3, true
+}
+
+func (p *BoldItalicParser) Parse(tokens []*tokenizer.Token) ast.Node {
+	size, ok := p.Match(tokens)
+	if size == 0 || !ok {
+		return nil
+	}
+
+	prefixTokenType := tokens[0].Type
+	contentTokens := tokens[3 : size-3]
+	return &ast.BoldItalic{
+		Symbol:  prefixTokenType,
+		Content: tokenizer.Stringify(contentTokens),
+	}
+}

plugin/gomark/parser/bold_italic_test.go

@@ -0,0 +1,49 @@
+package parser
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/usememos/memos/plugin/gomark/ast"
+	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+)
+
+func TestBoldItalicParser(t *testing.T) {
+	tests := []struct {
+		text       string
+		boldItalic ast.Node
+	}{
+		{
+			text:       "*Hello world!",
+			boldItalic: nil,
+		},
+		{
+			text: "***Hello***",
+			boldItalic: &ast.BoldItalic{
+				Symbol:  "*",
+				Content: "Hello",
+			},
+		},
+		{
+			text: "*** Hello ***",
+			boldItalic: &ast.BoldItalic{
+				Symbol:  "*",
+				Content: " Hello ",
+			},
+		},
+		{
+			text:       "*** Hello * *",
+			boldItalic: nil,
+		},
+		{
+			text:       "*** Hello **",
+			boldItalic: nil,
+		},
+	}
+
+	for _, test := range tests {
+		tokens := tokenizer.Tokenize(test.text)
+		require.Equal(t, test.boldItalic, NewBoldItalicParser().Parse(tokens))
+	}
+}

plugin/gomark/parser/code.go

@@ -7,10 +7,8 @@ import (
 
 type CodeParser struct{}
 
-var defaultCodeParser = &CodeParser{}
-
 func NewCodeParser() *CodeParser {
-	return defaultCodeParser
+	return &CodeParser{}
 }
 
 func (*CodeParser) Match(tokens []*tokenizer.Token) (int, bool) {

plugin/gomark/parser/code_block.go

@@ -10,10 +10,8 @@ type CodeBlockParser struct {
 	Content  string
 }
 
-var defaultCodeBlockParser = &CodeBlockParser{}
-
 func NewCodeBlockParser() *CodeBlockParser {
-	return defaultCodeBlockParser
+	return &CodeBlockParser{}
 }
 
 func (*CodeBlockParser) Match(tokens []*tokenizer.Token) (int, bool) {

plugin/gomark/parser/heading.go

@@ -62,11 +62,7 @@ func (p *HeadingParser) Parse(tokens []*tokenizer.Token) ast.Node {
 		}
 	}
 	contentTokens := tokens[level+1 : size]
-	children := ParseInline(contentTokens, []InlineParser{
-		NewBoldParser(),
-		NewCodeParser(),
-		NewTextParser(),
-	})
+	children := ParseInline(contentTokens)
 	return &ast.Heading{
 		Level:    level,
 		Children: children,

plugin/gomark/parser/horizontal_rule.go

@@ -0,0 +1,39 @@
+package parser
+
+import (
+	"github.com/usememos/memos/plugin/gomark/ast"
+	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+)
+
+type HorizontalRuleParser struct{}
+
+func NewHorizontalRuleParser() *HorizontalRuleParser {
+	return &HorizontalRuleParser{}
+}
+
+func (*HorizontalRuleParser) Match(tokens []*tokenizer.Token) (int, bool) {
+	if len(tokens) < 3 {
+		return 0, false
+	}
+	if tokens[0].Type != tokens[1].Type || tokens[0].Type != tokens[2].Type || tokens[1].Type != tokens[2].Type {
+		return 0, false
+	}
+	if tokens[0].Type != tokenizer.Dash && tokens[0].Type != tokenizer.Underline && tokens[0].Type != tokenizer.Asterisk {
+		return 0, false
+	}
+	if len(tokens) > 3 && tokens[3].Type != tokenizer.Newline {
+		return 0, false
+	}
+	return 3, true
+}
+
+func (p *HorizontalRuleParser) Parse(tokens []*tokenizer.Token) ast.Node {
+	size, ok := p.Match(tokens)
+	if size == 0 || !ok {
+		return nil
+	}
+
+	return &ast.HorizontalRule{
+		Symbol: tokens[0].Type,
+	}
+}

plugin/gomark/parser/horizontal_rule_test.go

@@ -0,0 +1,49 @@
+package parser
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/usememos/memos/plugin/gomark/ast"
+	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+)
+
+func TestHorizontalRuleParser(t *testing.T) {
+	tests := []struct {
+		text           string
+		horizontalRule ast.Node
+	}{
+		{
+			text: "---",
+			horizontalRule: &ast.HorizontalRule{
+				Symbol: "-",
+			},
+		},
+		{
+			text:           "****",
+			horizontalRule: nil,
+		},
+		{
+			text: "***",
+			horizontalRule: &ast.HorizontalRule{
+				Symbol: "*",
+			},
+		},
+		{
+			text:           "-*-",
+			horizontalRule: nil,
+		},
+		{
+			text: "___",
+			horizontalRule: &ast.HorizontalRule{
+				Symbol: "_",
+			},
+		},
+	}
+
+	for _, test := range tests {
+		tokens := tokenizer.Tokenize(test.text)
+		require.Equal(t, test.horizontalRule, NewHorizontalRuleParser().Parse(tokens))
+	}
+}

plugin/gomark/parser/image.go

@@ -7,10 +7,8 @@ import (
 
 type ImageParser struct{}
 
-var defaultImageParser = &ImageParser{}
-
 func NewImageParser() *ImageParser {
-	return defaultImageParser
+	return &ImageParser{}
 }
 
 func (*ImageParser) Match(tokens []*tokenizer.Token) (int, bool) {

plugin/gomark/parser/italic.go

@@ -1,6 +1,9 @@
 package parser
 
-import "github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+import (
+	"github.com/usememos/memos/plugin/gomark/ast"
+	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+)
 
 type ItalicParser struct {
 	ContentTokens []*tokenizer.Token
@@ -10,21 +13,21 @@ func NewItalicParser() *ItalicParser {
 	return &ItalicParser{}
 }
 
-func (*ItalicParser) Match(tokens []*tokenizer.Token) *ItalicParser {
+func (*ItalicParser) Match(tokens []*tokenizer.Token) (int, bool) {
 	if len(tokens) < 3 {
-		return nil
+		return 0, false
 	}
 
 	prefixTokens := tokens[:1]
-	if prefixTokens[0].Type != tokenizer.Star && prefixTokens[0].Type != tokenizer.Underline {
-		return nil
+	if prefixTokens[0].Type != tokenizer.Asterisk && prefixTokens[0].Type != tokenizer.Underline {
+		return 0, false
 	}
 	prefixTokenType := prefixTokens[0].Type
 	contentTokens := []*tokenizer.Token{}
 	matched := false
 	for _, token := range tokens[1:] {
 		if token.Type == tokenizer.Newline {
-			return nil
+			return 0, false
 		}
 		if token.Type == prefixTokenType {
 			matched = true
@@ -33,10 +36,22 @@ func (*ItalicParser) Match(tokens []*tokenizer.Token) *ItalicParser {
 		contentTokens = append(contentTokens, token)
 	}
 	if !matched || len(contentTokens) == 0 {
+		return 0, false
+	}
+
+	return len(contentTokens) + 2, true
+}
+
+func (p *ItalicParser) Parse(tokens []*tokenizer.Token) ast.Node {
+	size, ok := p.Match(tokens)
+	if size == 0 || !ok {
 		return nil
 	}
 
-	return &ItalicParser{
-		ContentTokens: contentTokens,
+	prefixTokenType := tokens[0].Type
+	contentTokens := tokens[1 : size-1]
+	return &ast.Italic{
+		Symbol:  prefixTokenType,
+		Content: tokenizer.Stringify(contentTokens),
 	}
 }

plugin/gomark/parser/italic_test.go

@@ -5,13 +5,14 @@ import (
 
 	"github.com/stretchr/testify/require"
 
+	"github.com/usememos/memos/plugin/gomark/ast"
 	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
 )
 
 func TestItalicParser(t *testing.T) {
 	tests := []struct {
 		text   string
-		italic *ItalicParser
+		italic ast.Node
 	}{
 		{
 			text:   "*Hello world!",
@@ -19,76 +20,29 @@ func TestItalicParser(t *testing.T) {
 		},
 		{
 			text: "*Hello*",
-			italic: &ItalicParser{
-				ContentTokens: []*tokenizer.Token{
-					{
-						Type:  tokenizer.Text,
-						Value: "Hello",
-					},
-				},
+			italic: &ast.Italic{
+				Symbol:  "*",
+				Content: "Hello",
 			},
 		},
 		{
 			text: "* Hello *",
-			italic: &ItalicParser{
-				ContentTokens: []*tokenizer.Token{
-					{
-						Type:  tokenizer.Space,
-						Value: " ",
-					},
-					{
-						Type:  tokenizer.Text,
-						Value: "Hello",
-					},
-					{
-						Type:  tokenizer.Space,
-						Value: " ",
-					},
-				},
+			italic: &ast.Italic{
+				Symbol:  "*",
+				Content: " Hello ",
 			},
 		},
-		{
-			text:   "** Hello * *",
-			italic: nil,
-		},
 		{
 			text: "*1* Hello * *",
-			italic: &ItalicParser{
-				ContentTokens: []*tokenizer.Token{
-					{
-						Type:  tokenizer.Text,
-						Value: "1",
-					},
-				},
+			italic: &ast.Italic{
+				Symbol:  "*",
+				Content: "1",
 			},
 		},
-		{
-			text: `* \n * Hello * *`,
-			italic: &ItalicParser{
-				ContentTokens: []*tokenizer.Token{
-					{
-						Type:  tokenizer.Space,
-						Value: " ",
-					},
-					{
-						Type:  tokenizer.Text,
-						Value: `\n`,
-					},
-					{
-						Type:  tokenizer.Space,
-						Value: " ",
-					},
-				},
-			},
-		},
-		{
-			text:   "* \n * Hello * *",
-			italic: nil,
-		},
 	}
 
 	for _, test := range tests {
 		tokens := tokenizer.Tokenize(test.text)
-		require.Equal(t, test.italic, NewItalicParser().Match(tokens))
+		require.Equal(t, test.italic, NewItalicParser().Parse(tokens))
 	}
 }

plugin/gomark/parser/line_break.go

@@ -7,10 +7,8 @@ import (
 
 type LineBreakParser struct{}
 
-var defaultLineBreakParser = &LineBreakParser{}
-
 func NewLineBreakParser() *LineBreakParser {
-	return defaultLineBreakParser
+	return &LineBreakParser{}
 }
 
 func (*LineBreakParser) Match(tokens []*tokenizer.Token) (int, bool) {

plugin/gomark/parser/link.go

@@ -1,58 +1,72 @@
 package parser
 
-import "github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+import (
+	"github.com/usememos/memos/plugin/gomark/ast"
+	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+)
 
-type LinkParser struct {
-	ContentTokens []*tokenizer.Token
-	URL           string
-}
+type LinkParser struct{}
 
 func NewLinkParser() *LinkParser {
 	return &LinkParser{}
 }
 
-func (*LinkParser) Match(tokens []*tokenizer.Token) *LinkParser {
-	if len(tokens) < 4 {
-		return nil
+func (*LinkParser) Match(tokens []*tokenizer.Token) (int, bool) {
+	if len(tokens) < 5 {
+		return 0, false
 	}
 	if tokens[0].Type != tokenizer.LeftSquareBracket {
-		return nil
+		return 0, false
 	}
-	cursor, contentTokens := 1, []*tokenizer.Token{}
-	for ; cursor < len(tokens)-2; cursor++ {
-		if tokens[cursor].Type == tokenizer.Newline {
-			return nil
+	textTokens := []*tokenizer.Token{}
+	for _, token := range tokens[1:] {
+		if token.Type == tokenizer.Newline {
+			return 0, false
 		}
-		if tokens[cursor].Type == tokenizer.RightSquareBracket {
+		if token.Type == tokenizer.RightSquareBracket {
 			break
 		}
-		contentTokens = append(contentTokens, tokens[cursor])
+		textTokens = append(textTokens, token)
 	}
-	if tokens[cursor+1].Type != tokenizer.LeftParenthesis {
-		return nil
+	if len(textTokens)+4 >= len(tokens) {
+		return 0, false
+	}
+	if tokens[2+len(textTokens)].Type != tokenizer.LeftParenthesis {
+		return 0, false
 	}
-	matched, url := false, ""
-	for _, token := range tokens[cursor+2:] {
+	urlTokens := []*tokenizer.Token{}
+	for _, token := range tokens[3+len(textTokens):] {
 		if token.Type == tokenizer.Newline || token.Type == tokenizer.Space {
-			return nil
+			return 0, false
 		}
 		if token.Type == tokenizer.RightParenthesis {
-			matched = true
 			break
 		}
-		url += token.Value
+		urlTokens = append(urlTokens, token)
+	}
+	if 4+len(urlTokens)+len(textTokens) > len(tokens) {
+		return 0, false
 	}
-	if !matched || url == "" {
+
+	return 4 + len(urlTokens) + len(textTokens), true
+}
+
+func (p *LinkParser) Parse(tokens []*tokenizer.Token) ast.Node {
+	size, ok := p.Match(tokens)
+	if size == 0 || !ok {
 		return nil
 	}
-	if len(contentTokens) == 0 {
-		contentTokens = append(contentTokens, &tokenizer.Token{
-			Type:  tokenizer.Text,
-			Value: url,
-		})
+
+	textTokens := []*tokenizer.Token{}
+	for _, token := range tokens[1:] {
+		if token.Type == tokenizer.RightSquareBracket {
+			break
+		}
+		textTokens = append(textTokens, token)
 	}
-	return &LinkParser{
-		ContentTokens: contentTokens,
-		URL:           url,
+	urlTokens := tokens[2+len(textTokens)+1 : size-1]
+	return &ast.Link{
+		Text: tokenizer.Stringify(textTokens),
+		URL:  tokenizer.Stringify(urlTokens),
 	}
 }

plugin/gomark/parser/link_test.go

@@ -5,24 +5,20 @@ import (
 
 	"github.com/stretchr/testify/require"
 
+	"github.com/usememos/memos/plugin/gomark/ast"
 	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
 )
 
 func TestLinkParser(t *testing.T) {
 	tests := []struct {
 		text string
-		link *LinkParser
+		link ast.Node
 	}{
 		{
 			text: "[](https://example.com)",
-			link: &LinkParser{
-				ContentTokens: []*tokenizer.Token{
-					{
-						Type:  tokenizer.Text,
-						Value: "https://example.com",
-					},
-				},
-				URL: "https://example.com",
+			link: &ast.Link{
+				Text: "",
+				URL:  "https://example.com",
 			},
 		},
 		{
@@ -35,27 +31,14 @@ func TestLinkParser(t *testing.T) {
 		},
 		{
 			text: "[hello world](https://example.com)",
-			link: &LinkParser{
-				ContentTokens: []*tokenizer.Token{
-					{
-						Type:  tokenizer.Text,
-						Value: "hello",
-					},
-					{
-						Type:  tokenizer.Space,
-						Value: " ",
-					},
-					{
-						Type:  tokenizer.Text,
-						Value: "world",
-					},
-				},
-				URL: "https://example.com",
+			link: &ast.Link{
+				Text: "hello world",
+				URL:  "https://example.com",
 			},
 		},
 	}
 	for _, test := range tests {
 		tokens := tokenizer.Tokenize(test.text)
-		require.Equal(t, test.link, NewLinkParser().Match(tokens))
+		require.Equal(t, test.link, NewLinkParser().Parse(tokens))
 	}
 }

plugin/gomark/parser/paragraph.go

@@ -9,10 +9,8 @@ type ParagraphParser struct {
 	ContentTokens []*tokenizer.Token
 }
 
-var defaultParagraphParser = &ParagraphParser{}
-
 func NewParagraphParser() *ParagraphParser {
-	return defaultParagraphParser
+	return &ParagraphParser{}
 }
 
 func (*ParagraphParser) Match(tokens []*tokenizer.Token) (int, bool) {
@@ -38,10 +36,7 @@ func (p *ParagraphParser) Parse(tokens []*tokenizer.Token) ast.Node {
 	}
 
 	contentTokens := tokens[:size]
-	children := ParseInline(contentTokens, []InlineParser{
-		NewBoldParser(),
-		NewTextParser(),
-	})
+	children := ParseInline(contentTokens)
 	return &ast.Paragraph{
 		Children: children,
 	}

plugin/gomark/parser/parser.go

@@ -1,6 +1,8 @@
 package parser
 
 import (
+	"errors"
+
 	"github.com/usememos/memos/plugin/gomark/ast"
 	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
 )
@@ -23,32 +25,51 @@ type BlockParser interface {
 	BaseParser
 }
 
-func Parse(tokens []*tokenizer.Token) []ast.Node {
+var defaultBlockParsers = []BlockParser{
+	NewCodeBlockParser(),
+	NewHorizontalRuleParser(),
+	NewHeadingParser(),
+	NewBlockquoteParser(),
+	NewParagraphParser(),
+	NewLineBreakParser(),
+}
+
+func Parse(tokens []*tokenizer.Token) ([]ast.Node, error) {
 	nodes := []ast.Node{}
-	blockParsers := []BlockParser{
-		NewCodeBlockParser(),
-		NewParagraphParser(),
-		NewLineBreakParser(),
-	}
 	for len(tokens) > 0 {
-		for _, blockParser := range blockParsers {
+		for _, blockParser := range defaultBlockParsers {
 			cursor, matched := blockParser.Match(tokens)
 			if matched {
 				node := blockParser.Parse(tokens)
+				if node == nil {
+					return nil, errors.New("parse error")
+				}
 				nodes = append(nodes, node)
 				tokens = tokens[cursor:]
 				break
 			}
 		}
 	}
-	return nodes
+	return nodes, nil
+}
+
+var defaultInlineParsers = []InlineParser{
+	NewBoldItalicParser(),
+	NewImageParser(),
+	NewLinkParser(),
+	NewBoldParser(),
+	NewItalicParser(),
+	NewCodeParser(),
+	NewTagParser(),
+	NewStrikethroughParser(),
+	NewTextParser(),
 }
 
-func ParseInline(tokens []*tokenizer.Token, inlineParsers []InlineParser) []ast.Node {
+func ParseInline(tokens []*tokenizer.Token) []ast.Node {
 	nodes := []ast.Node{}
 	var lastNode ast.Node
 	for len(tokens) > 0 {
-		for _, inlineParser := range inlineParsers {
+		for _, inlineParser := range defaultInlineParsers {
 			cursor, matched := inlineParser.Match(tokens)
 			if matched {
 				node := inlineParser.Parse(tokens)

plugin/gomark/parser/parser_test.go

@@ -89,6 +89,8 @@ func TestParser(t *testing.T) {
 
 	for _, test := range tests {
 		tokens := tokenizer.Tokenize(test.text)
-		require.Equal(t, test.nodes, Parse(tokens))
+		nodes, err := Parse(tokens)
+		require.NoError(t, err)
+		require.Equal(t, test.nodes, nodes)
 	}
 }

plugin/gomark/parser/strikethrough.go

@@ -0,0 +1,49 @@
+package parser
+
+import (
+	"github.com/usememos/memos/plugin/gomark/ast"
+	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+)
+
+type StrikethroughParser struct{}
+
+func NewStrikethroughParser() *StrikethroughParser {
+	return &StrikethroughParser{}
+}
+
+func (*StrikethroughParser) Match(tokens []*tokenizer.Token) (int, bool) {
+	if len(tokens) < 5 {
+		return 0, false
+	}
+	if tokens[0].Type != tokenizer.Tilde || tokens[1].Type != tokenizer.Tilde {
+		return 0, false
+	}
+
+	cursor, matched := 2, false
+	for ; cursor < len(tokens)-1; cursor++ {
+		token, nextToken := tokens[cursor], tokens[cursor+1]
+		if token.Type == tokenizer.Newline || nextToken.Type == tokenizer.Newline {
+			return 0, false
+		}
+		if token.Type == tokenizer.Tilde && nextToken.Type == tokenizer.Tilde {
+			matched = true
+			break
+		}
+	}
+	if !matched {
+		return 0, false
+	}
+	return cursor + 2, true
+}
+
+func (p *StrikethroughParser) Parse(tokens []*tokenizer.Token) ast.Node {
+	size, ok := p.Match(tokens)
+	if size == 0 || !ok {
+		return nil
+	}
+
+	contentTokens := tokens[2 : size-2]
+	return &ast.Strikethrough{
+		Content: tokenizer.Stringify(contentTokens),
+	}
+}

plugin/gomark/parser/strikethrough_test.go

@@ -0,0 +1,45 @@
+package parser
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/usememos/memos/plugin/gomark/ast"
+	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+)
+
+func TestStrikethroughParser(t *testing.T) {
+	tests := []struct {
+		text          string
+		strikethrough ast.Node
+	}{
+		{
+			text:          "~~Hello world",
+			strikethrough: nil,
+		},
+		{
+			text: "~~Hello~~",
+			strikethrough: &ast.Strikethrough{
+				Content: "Hello",
+			},
+		},
+		{
+			text: "~~ Hello ~~",
+			strikethrough: &ast.Strikethrough{
+				Content: " Hello ",
+			},
+		},
+		{
+			text: "~~1~~ Hello ~~~",
+			strikethrough: &ast.Strikethrough{
+				Content: "1",
+			},
+		},
+	}
+
+	for _, test := range tests {
+		tokens := tokenizer.Tokenize(test.text)
+		require.Equal(t, test.strikethrough, NewStrikethroughParser().Parse(tokens))
+	}
+}

plugin/gomark/parser/tag.go

@@ -1,21 +1,22 @@
 package parser
 
-import "github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+import (
+	"github.com/usememos/memos/plugin/gomark/ast"
+	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
+)
 
-type TagParser struct {
-	ContentTokens []*tokenizer.Token
-}
+type TagParser struct{}
 
 func NewTagParser() *TagParser {
 	return &TagParser{}
 }
 
-func (*TagParser) Match(tokens []*tokenizer.Token) *TagParser {
+func (*TagParser) Match(tokens []*tokenizer.Token) (int, bool) {
 	if len(tokens) < 2 {
-		return nil
+		return 0, false
 	}
 	if tokens[0].Type != tokenizer.Hash {
-		return nil
+		return 0, false
 	}
 	contentTokens := []*tokenizer.Token{}
 	for _, token := range tokens[1:] {
@@ -25,10 +26,20 @@ func (*TagParser) Match(tokens []*tokenizer.Token) *TagParser {
 		contentTokens = append(contentTokens, token)
 	}
 	if len(contentTokens) == 0 {
+		return 0, false
+	}
+
+	return len(contentTokens) + 1, true
+}
+
+func (p *TagParser) Parse(tokens []*tokenizer.Token) ast.Node {
+	size, ok := p.Match(tokens)
+	if size == 0 || !ok {
 		return nil
 	}
 
-	return &TagParser{
-		ContentTokens: contentTokens,
+	contentTokens := tokens[1:size]
+	return &ast.Tag{
+		Content: tokenizer.Stringify(contentTokens),
 	}
 }

plugin/gomark/parser/tag_test.go

@@ -5,13 +5,14 @@ import (
 
 	"github.com/stretchr/testify/require"
 
+	"github.com/usememos/memos/plugin/gomark/ast"
 	"github.com/usememos/memos/plugin/gomark/parser/tokenizer"
 )
 
 func TestTagParser(t *testing.T) {
 	tests := []struct {
 		text string
-		tag  *TagParser
+		tag  ast.Node
 	}{
 		{
 			text: "*Hello world",
@@ -23,30 +24,20 @@ func TestTagParser(t *testing.T) {
 		},
 		{
 			text: "#tag",
-			tag: &TagParser{
-				ContentTokens: []*tokenizer.Token{
-					{
-						Type:  tokenizer.Text,
-						Value: "tag",
-					},
-				},
+			tag: &ast.Tag{
+				Content: "tag",
 			},
 		},
 		{
-			text: "#tag/subtag",
-			tag: &TagParser{
-				ContentTokens: []*tokenizer.Token{
-					{
-						Type:  tokenizer.Text,
-						Value: "tag/subtag",
-					},
-				},
+			text: "#tag/subtag 123",
+			tag: &ast.Tag{
+				Content: "tag/subtag",
 			},
 		},
 	}
 
 	for _, test := range tests {
 		tokens := tokenizer.Tokenize(test.text)
-		require.Equal(t, test.tag, NewTagParser().Match(tokens))
+		require.Equal(t, test.tag, NewTagParser().Parse(tokens))
 	}
 }

plugin/gomark/parser/text.go

@@ -9,10 +9,8 @@ type TextParser struct {
 	Content string
 }
 
-var defaultTextParser = &TextParser{}
-
 func NewTextParser() *TextParser {
-	return defaultTextParser
+	return &TextParser{}
 }
 
 func (*TextParser) Match(tokens []*tokenizer.Token) (int, bool) {

plugin/gomark/parser/tokenizer/tokenizer.go

@@ -4,7 +4,7 @@ type TokenType = string
 
 const (
 	Underline          TokenType = "_"
-	Star               TokenType = "*"
+	Asterisk           TokenType = "*"
 	Hash               TokenType = "#"
 	Backtick           TokenType = "`"
 	LeftSquareBracket  TokenType = "["
@@ -12,6 +12,9 @@ const (
 	LeftParenthesis    TokenType = "("
 	RightParenthesis   TokenType = ")"
 	ExclamationMark    TokenType = "!"
+	Tilde              TokenType = "~"
+	Dash               TokenType = "-"
+	GreaterThan        TokenType = ">"
 	Newline            TokenType = "\n"
 	Space              TokenType = " "
 )
@@ -39,7 +42,7 @@ func Tokenize(text string) []*Token {
 		case '_':
 			tokens = append(tokens, NewToken(Underline, "_"))
 		case '*':
-			tokens = append(tokens, NewToken(Star, "*"))
+			tokens = append(tokens, NewToken(Asterisk, "*"))
 		case '#':
 			tokens = append(tokens, NewToken(Hash, "#"))
 		case '`':
@@ -54,6 +57,12 @@ func Tokenize(text string) []*Token {
 			tokens = append(tokens, NewToken(RightParenthesis, ")"))
 		case '!':
 			tokens = append(tokens, NewToken(ExclamationMark, "!"))
+		case '~':
+			tokens = append(tokens, NewToken(Tilde, "~"))
+		case '-':
+			tokens = append(tokens, NewToken(Dash, "-"))
+		case '>':
+			tokens = append(tokens, NewToken(GreaterThan, ">"))
 		case '\n':
 			tokens = append(tokens, NewToken(Newline, "\n"))
 		case ' ':

plugin/gomark/parser/tokenizer/tokenizer_test.go

@@ -15,7 +15,7 @@ func TestTokenize(t *testing.T) {
 			text: "*Hello world!",
 			tokens: []*Token{
 				{
-					Type:  Star,
+					Type:  Asterisk,
 					Value: "*",
 				},
 				{