Put selector functions etc. into a parent env instead of the same env…

…ironment as topic aliases.

Fixes r-lib#2396.

R/topics.R

@@ -61,10 +61,11 @@ all_sign <- function(x, text) {
 }
 
 match_env <- function(topics) {
-  out <- env(empty_env(),
+  fns <- env(empty_env(),
     "-" = function(x) -x,
     "c" = function(...) c(...)
   )
+  out <- env(fns)
 
   topic_index <- seq_along(topics$name)
 
@@ -99,36 +100,36 @@ match_env <- function(topics) {
   is_public <- function(internal) {
     if (!internal) !topics$internal else rep(TRUE, nrow(topics))
   }
-  out$starts_with <- function(x, internal = FALSE) {
+  fns$starts_with <- function(x, internal = FALSE) {
     any_alias(~ grepl(paste0("^", x), .), .internal = internal)
   }
-  out$ends_with <- function(x, internal = FALSE) {
+  fns$ends_with <- function(x, internal = FALSE) {
     any_alias(~ grepl(paste0(x, "$"), .), .internal = internal)
   }
-  out$matches <- function(x, internal = FALSE) {
+  fns$matches <- function(x, internal = FALSE) {
     any_alias(~ grepl(x, .), .internal = internal)
   }
-  out$contains <- function(x, internal = FALSE) {
+  fns$contains <- function(x, internal = FALSE) {
     any_alias(~ grepl(x, ., fixed = TRUE), .internal = internal)
   }
-  out$has_keyword <- function(x) {
+  fns$has_keyword <- function(x) {
     which(purrr::map_lgl(topics$keywords, ~ any(. %in% x)))
   }
-  out$has_concept <- function(x, internal = FALSE) {
+  fns$has_concept <- function(x, internal = FALSE) {
     match <- topics$concepts %>%
       purrr::map(~ str_trim(.) == x) %>%
       purrr::map_lgl(any)
 
     which(match & is_public(internal))
   }
-  out$lacks_concepts <- function(x, internal = FALSE) {
+  fns$lacks_concepts <- function(x, internal = FALSE) {
     nomatch <- topics$concepts %>%
       purrr::map(~ match(str_trim(.), x, nomatch = FALSE)) %>%
       purrr::map_lgl(~ length(.) == 0L | all(. == 0L))
 
     which(nomatch & is_public(internal))
   }
-  out$lacks_concept <- out$lacks_concepts
+  fns$lacks_concept <- fns$lacks_concepts
   out
 }