add comments

teunbrand · teunbrand · commit 077b268becdc · 2025-10-07T16:01:12.000+02:00
diff --git a/R/layer.R b/R/layer.R
@@ -971,10 +971,13 @@ normalise_label <- function(label) {
     return(NULL)
   }
   if (obj_is_list(label)) {
+    # Ensure that element in the list has length 1
     label[lengths(label) == 0] <- ""
     labels <- lapply(labels, `[`, i)
   }
   if (is.expression(label)) {
+    # Subclasses expressions, when converted to lists, retain their class.
+    # The unclass is needed to properly treat it as a vctrs-compatible list.
     label <- unclass(as.list(label))
   }
   label

Original file line number	Diff line number	Diff line change
`@@ -971,10 +971,13 @@ normalise_label <- function(label) {`
`971`	`971`	`return(NULL)`
`972`	`972`	`}`
`973`	`973`	`if (obj_is_list(label)) {`
	`974`	`+ # Ensure that element in the list has length 1`
`974`	`975`	`label[lengths(label) == 0] <- ""`
`975`	`976`	labels <- lapply(labels, `[`, i)
`976`	`977`	`}`
`977`	`978`	`if (is.expression(label)) {`
	`979`	`+ # Subclasses expressions, when converted to lists, retain their class.`
	`980`	`+ # The unclass is needed to properly treat it as a vctrs-compatible list.`
`978`	`981`	`label <- unclass(as.list(label))`
`979`	`982`	`}`
`980`	`983`	`label`