cue/ast: remove Node.Comments and Node.AddComment

And deprecate the methods which get promoted into every Node
implementation, which is what many users end up actually using.

These Node methods were deprecated back in late 2019 in
https://cue-review.googlesource.com/c/cue/+/3221,
more than six years ago, so at this point they can be removed.

The corresponding methods in the comments type, which are promoted
into every Node implementation via embedding, were not deprecated yet.
As such, removing them outright doesn't seem fair to users.
Deprecate them now, and leave a note to remove in the future.

Signed-off-by: Daniel Martí <[email protected]>
Change-Id: I321ae429e91e004f51a0824e98088cf1cc28e11e
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1224693
TryBot-Result: CUEcueckoo <[email protected]>
Reviewed-by: Roger Peppe <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>

Author: mvdan

cue/ast/ast.go

@@ -55,11 +55,6 @@ type Node interface {
 	// the node or nil if there is no such position.
 	pos() *token.Pos
 
-	// Deprecated: use [Comments]
-	Comments() []*CommentGroup
-
-	// Deprecated: use [AddComment]
-	AddComment(*CommentGroup)
 	commentInfo() *comments
 }
 
@@ -147,13 +142,20 @@ type comments struct {
 
 func (c *comments) commentInfo() *comments { return c }
 
+// TODO: remove these deprecated comment methods in late 2026.
+// Note that we unfortunately cannot use `//go:fix inline`;
+// for example, from the comments.Comments promoted method below,
+// we cannot call the Comments API as it works on Node, the embedding type.
+
+// Deprecated: use [Comments].
 func (c *comments) Comments() []*CommentGroup {
 	if c.groups == nil {
 		return []*CommentGroup{}
 	}
 	return *c.groups
 }
 
+// Deprecated: use [AddComment].
 func (c *comments) AddComment(cg *CommentGroup) {
 	if cg == nil {
 		return
@@ -171,6 +173,7 @@ func (c *comments) AddComment(cg *CommentGroup) {
 	}
 }
 
+// Deprecated: use [SetComments].
 func (c *comments) SetComments(cgs []*CommentGroup) {
 	if c.groups == nil {
 		if cgs == nil {