refactor: move variables closer to their usage, add assert_character()

R/attributes.R

@@ -461,6 +461,7 @@ set_vertex_attr <- function(graph, name, index = V(graph), value) {
 
 i_set_vertex_attr <- function(graph, name, index = V(graph), value, check = TRUE) {
   ensure_igraph(graph)
+  assert_character(name)
 
   if (is.null(value)) {
     return(graph)
@@ -472,19 +473,19 @@ i_set_vertex_attr <- function(graph, name, index = V(graph), value, check = TRUE
     value <- as.numeric(value)
   }
 
-  single <- is_single_index(index)
-  complete <- is_complete_iterator(index)
   if (!missing(index) && check) {
     index <- as_igraph_vs(graph, index)
   }
-  name <- as.character(name)
 
   vattrs <- .Call(R_igraph_mybracket2, graph, igraph_t_idx_attr, igraph_attr_idx_vertex)
 
-  if (!complete && !(name %in% names(vattrs))) {
+  complete <- is_complete_iterator(index)
+  name_available <- (name %in% names(vattrs))
+  if (!complete && !name_available) {
     vattrs[[name]] <- value[rep.int(NA_integer_, vcount(graph))]
   }
 
+  single <- is_single_index(index)
   if (single) {
     vattrs[[name]][[index]] <- value
   } else {

R/utils-assert.R

@@ -0,0 +1,5 @@
+assert_character <- function(x, name) {
+  if (!inherits(x, "character")) {
+    cli::cli_abort("{.arg {name}} must be a character, not {.obj_type_friendly {x}}.")
+  }
+}