Refactor parser (#545)

* refactor parser

ast/ast.go

@@ -1762,6 +1762,14 @@ type TagNode struct {
 	Value Node
 }
 
+func (n *TagNode) GetValue() any {
+	scalar, ok := n.Value.(ScalarNode)
+	if !ok {
+		return nil
+	}
+	return scalar.GetValue()
+}
+
 func (n *TagNode) stringWithoutComment() string {
 	return n.Value.String()
 }

decode.go

@@ -215,6 +215,14 @@ func (d *Decoder) addHeadOrLineCommentToMap(node ast.Node) {
 	}
 	commentPath := node.GetPath()
 	if minCommentLine < targetLine {
+		switch n := node.(type) {
+		case *ast.MappingNode:
+			if len(n.Values) != 0 {
+				commentPath = n.Values[0].Key.GetPath()
+			}
+		case *ast.MappingValueNode:
+			commentPath = n.Key.GetPath()
+		}
 		d.addCommentToMap(commentPath, HeadComment(texts...))
 	} else {
 		d.addCommentToMap(commentPath, LineComment(texts[0]))
@@ -255,14 +263,20 @@ func (d *Decoder) addFootCommentToMap(node ast.Node) {
 	)
 	switch n := node.(type) {
 	case *ast.SequenceNode:
-		if len(n.Values) != 0 {
-			footCommentPath = n.Values[len(n.Values)-1].GetPath()
-		}
 		footComment = n.FootComment
+		if n.FootComment != nil {
+			footCommentPath = n.FootComment.GetPath()
+		}
 	case *ast.MappingNode:
 		footComment = n.FootComment
+		if n.FootComment != nil {
+			footCommentPath = n.FootComment.GetPath()
+		}
 	case *ast.MappingValueNode:
 		footComment = n.FootComment
+		if n.FootComment != nil {
+			footCommentPath = n.FootComment.GetPath()
+		}
 	}
 	if footComment == nil {
 		return

parser/color.go

@@ -0,0 +1,28 @@
+package parser
+
+import "fmt"
+
+const (
+	colorFgHiBlack int = iota + 90
+	colorFgHiRed
+	colorFgHiGreen
+	colorFgHiYellow
+	colorFgHiBlue
+	colorFgHiMagenta
+	colorFgHiCyan
+)
+
+var colorTable = []int{
+	colorFgHiRed,
+	colorFgHiGreen,
+	colorFgHiYellow,
+	colorFgHiBlue,
+	colorFgHiMagenta,
+	colorFgHiCyan,
+}
+
+func colorize(idx int, content string) string {
+	colorIdx := idx % len(colorTable)
+	color := colorTable[colorIdx]
+	return fmt.Sprintf("\x1b[1;%dm", color) + content + "\x1b[22;0m"
+}

parser/context.go

@@ -3,13 +3,21 @@ package parser
 import (
 	"fmt"
 	"strings"
+
+	"github.com/goccy/go-yaml/token"
 )
 
 // context context at parsing
 type context struct {
+	tokenRef *tokenRef
 	path     string
 	isFlow   bool
-	isMapKey bool
+}
+
+type tokenRef struct {
+	tokens []*Token
+	size   int
+	idx    int
 }
 
 var pathSpecialChars = []string{
@@ -32,6 +40,44 @@ func normalizePath(path string) string {
 	return path
 }
 
+func (c *context) currentToken() *Token {
+	if c.tokenRef.idx >= c.tokenRef.size {
+		return nil
+	}
+	return c.tokenRef.tokens[c.tokenRef.idx]
+}
+
+func (c *context) isComment() bool {
+	return c.currentToken().Type() == token.CommentType
+}
+
+func (c *context) nextToken() *Token {
+	if c.tokenRef.idx+1 >= c.tokenRef.size {
+		return nil
+	}
+	return c.tokenRef.tokens[c.tokenRef.idx+1]
+}
+
+func (c *context) nextNotCommentToken() *Token {
+	for i := c.tokenRef.idx + 1; i < c.tokenRef.size; i++ {
+		tk := c.tokenRef.tokens[i]
+		if tk.Type() == token.CommentType {
+			continue
+		}
+		return tk
+	}
+	return nil
+}
+
+func (c *context) withGroup(g *TokenGroup) *context {
+	ctx := *c
+	ctx.tokenRef = &tokenRef{
+		tokens: g.Tokens,
+		size:   len(g.Tokens),
+	}
+	return &ctx
+}
+
 func (c *context) withChild(path string) *context {
 	ctx := *c
 	ctx.path = c.path + "." + normalizePath(path)
@@ -50,14 +96,60 @@ func (c *context) withFlow(isFlow bool) *context {
 	return &ctx
 }
 
-func (c *context) withMapKey() *context {
-	ctx := *c
-	ctx.isMapKey = true
-	return &ctx
-}
-
 func newContext() *context {
 	return &context{
 		path: "$",
 	}
 }
+
+func (c *context) goNext() {
+	ref := c.tokenRef
+	if ref.size <= ref.idx+1 {
+		ref.idx = ref.size
+	} else {
+		ref.idx++
+	}
+}
+
+func (c *context) next() bool {
+	return c.tokenRef.idx < c.tokenRef.size
+}
+
+func (c *context) insertNullToken(tk *Token) *Token {
+	nullToken := c.createNullToken(tk)
+	c.insertToken(nullToken)
+	c.goNext()
+
+	return nullToken
+}
+
+func (c *context) createNullToken(base *Token) *Token {
+	pos := *(base.RawToken().Position)
+	pos.Column++
+	return &Token{Token: token.New("null", "null", &pos)}
+}
+
+func (c *context) insertToken(tk *Token) {
+	ref := c.tokenRef
+	idx := ref.idx
+	if ref.size < idx {
+		return
+	}
+	if ref.size == idx {
+		curToken := ref.tokens[ref.size-1]
+		tk.RawToken().Next = curToken.RawToken()
+		curToken.RawToken().Prev = tk.RawToken()
+
+		ref.tokens = append(ref.tokens, tk)
+		ref.size = len(ref.tokens)
+		return
+	}
+
+	curToken := ref.tokens[idx]
+	tk.RawToken().Next = curToken.RawToken()
+	curToken.RawToken().Prev = tk.RawToken()
+
+	ref.tokens = append(ref.tokens[:idx+1], ref.tokens[idx:]...)
+	ref.tokens[idx] = tk
+	ref.size = len(ref.tokens)
+}