cue/ast: add API to modify comments
Adding more methods to nodes makes the API rather
cluttered. We deprecate the interface methods
in favor of functions.
Change-Id: Ie791855720249e198082c9a76a87a26e21e82375
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/3221
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
diff --git a/cue/ast/ast.go b/cue/ast/ast.go
index da6b72c..01f16c4 100644
--- a/cue/ast/ast.go
+++ b/cue/ast/ast.go
@@ -44,8 +44,12 @@
// TODO: SetPos(p token.RelPos)
+ // Deprecated: use ast.Comments
Comments() []*CommentGroup
+
+ // Deprecated: use ast.AddComment
AddComment(*CommentGroup)
+ commentInfo() *comments
}
// An Expr is implemented by all expression nodes.
@@ -117,6 +121,8 @@
groups *[]*CommentGroup
}
+func (c *comments) commentInfo() *comments { return c }
+
func (c *comments) Comments() []*CommentGroup {
if c.groups == nil {
return []*CommentGroup{}
@@ -139,14 +145,24 @@
*c.groups = append(*c.groups, cg)
}
+func (c *comments) SetComments(cgs []*CommentGroup) {
+ if c.groups == nil {
+ a := cgs
+ c.groups = &a
+ return
+ }
+ *c.groups = cgs
+}
+
// A Comment node represents a single //-style or /*-style comment.
type Comment struct {
Slash token.Pos // position of "/" starting the comment
Text string // comment text (excluding '\n' for //-style comments)
}
-func (g *Comment) Comments() []*CommentGroup { return nil }
-func (g *Comment) AddComment(*CommentGroup) {}
+func (c *Comment) Comments() []*CommentGroup { return nil }
+func (c *Comment) AddComment(*CommentGroup) {}
+func (c *Comment) commentInfo() *comments { return nil }
func (c *Comment) Pos() token.Pos { return c.Slash }
func (c *Comment) End() token.Pos { return c.Slash.Add(len(c.Text)) }
@@ -171,6 +187,7 @@
func (g *CommentGroup) Comments() []*CommentGroup { return nil }
func (g *CommentGroup) AddComment(*CommentGroup) {}
+func (g *CommentGroup) commentInfo() *comments { return nil }
func isWhitespace(ch byte) bool { return ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r' }
diff --git a/cue/ast/astutil/apply.go b/cue/ast/astutil/apply.go
index 4e747f5..22deb16 100644
--- a/cue/ast/astutil/apply.go
+++ b/cue/ast/astutil/apply.go
@@ -42,7 +42,9 @@
Index() int
// Replace replaces the current Node with n.
- // The replacement node is not walked by Apply.
+ // The replacement node is not walked by Apply. Comments of the old node
+ // are copied to the new node if it has not yet an comments associated
+ // with it.
Replace(n ast.Node)
// Delete deletes the current Node from its containing struct.
@@ -84,6 +86,9 @@
func (c *cursor) Replace(n ast.Node) {
// panic if the value cannot convert to the original type.
reflect.ValueOf(n).Convert(reflect.TypeOf(c.typ).Elem())
+ if ast.Comments(n) != nil {
+ CopyComments(n, c.node)
+ }
c.node = n
c.replaced = true
}
diff --git a/cue/ast/astutil/apply_test.go b/cue/ast/astutil/apply_test.go
index 4a2eebf..7ed8f08 100644
--- a/cue/ast/astutil/apply_test.go
+++ b/cue/ast/astutil/apply_test.go
@@ -116,13 +116,15 @@
}, {
name: "replace",
in: `
- a: "string"
+ // keep comment
+ a: "string" // and this one
b: 3
c: [ 1, 2, 8, 4 ]
d: "\(foo) is \(0)"
`,
out: `
-a: s
+// keep comment
+a: s // and this one
b: 4
c: [4, 4, 4, 4]
d: "\(foo) is \(4)"
diff --git a/cue/ast/astutil/util.go b/cue/ast/astutil/util.go
new file mode 100644
index 0000000..2a237b3
--- /dev/null
+++ b/cue/ast/astutil/util.go
@@ -0,0 +1,26 @@
+// Copyright 2019 CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package astutil
+
+import "cuelang.org/go/cue/ast"
+
+// CopyComments associates comments of one node with another.
+// It may change the relative position of comments.
+func CopyComments(to, from ast.Node) {
+ if from == nil {
+ return
+ }
+ ast.SetComments(to, from.Comments())
+}
diff --git a/cue/ast/comments.go b/cue/ast/comments.go
new file mode 100644
index 0000000..09d5402
--- /dev/null
+++ b/cue/ast/comments.go
@@ -0,0 +1,46 @@
+// Copyright 2019 CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ast
+
+// Comments returns all comments associated with a given node.
+func Comments(n Node) []*CommentGroup {
+ c := n.commentInfo()
+ if c == nil {
+ return nil
+ }
+ return c.Comments()
+}
+
+// AddComment adds the given comment to the node if it supports it.
+// If a node does not support comments, such as for CommentGroup or Comment,
+// this call has no effect.
+func AddComment(n Node, cg *CommentGroup) {
+ c := n.commentInfo()
+ if c == nil {
+ return
+ }
+ c.AddComment(cg)
+}
+
+// SetComments replaces all comments of n with the given set of comments.
+// If a node does not support comments, such as for CommentGroup or Comment,
+// this call has no effect.
+func SetComments(n Node, cgs []*CommentGroup) {
+ c := n.commentInfo()
+ if c == nil {
+ return
+ }
+ c.SetComments(cgs)
+}
diff --git a/cue/ast/walk.go b/cue/ast/walk.go
index 1dfd1a0..85a45fc 100644
--- a/cue/ast/walk.go
+++ b/cue/ast/walk.go
@@ -64,7 +64,7 @@
// TODO: record the comment groups and interleave with the values like for
// parsing and printing?
- for _, c := range node.Comments() {
+ for _, c := range Comments(node) {
walk(v, c)
}
@@ -221,7 +221,7 @@
func (f *inspector) Before(node Node) visitor {
if f.before == nil || f.before(node) {
f.commentStack = append(f.commentStack, f.current)
- f.current = commentFrame{cg: node.Comments()}
+ f.current = commentFrame{cg: Comments(node)}
f.visitComments(f.current.pos)
return f
}
