in.order(&x.LParen)
		for _, l := range x.Line {
			in.order(l)
		}
		in.order(&x.RParen)
	}
	if x != nil {
		in.post = append(in.post, x)
	}
}

// assignComments attaches comments to nearby syntax.
func (in *input) assignComments() {
	const debug = false

	// Generate preorder and postorder lists.
	in.order(in.file)

	// Split into whole-line comments and suffix comments.