Replace ranking expression by a function in top_n()

tidyverse · Jul 2, 2019 · bf4edf5 · bf4edf5
1 parent 1131d64
commit bf4edf5
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Showing 2 changed files with 11 additions and 13 deletions.
diff --git a/DESCRIPTION b/DESCRIPTION
@@ -24,7 +24,7 @@ Imports:
     pkgconfig,
     R6,
     Rcpp (>= 1.0.1),
-    rlang (>= 0.3.1),
+    rlang (>= 0.4.0),
     tibble (>= 2.0.0),
     tidyselect (>= 0.2.5),
     utils

diff --git a/R/top-n.R b/R/top-n.R
@@ -52,29 +52,27 @@
 #' }
 #' }
 top_n <- function(x, n, wt) {
-  nn <- enquo(n)
   wt <- enquo(wt)
-
   if (quo_is_missing(wt)) {
     vars <- tbl_vars(x)
     wt_name <- vars[length(vars)]
     inform(glue("Selecting by ", wt_name))
     wt <- sym(wt_name)
   }
 
-  pred <- expr(local({
-    .n <- !!nn
-    if (.n > 0) {
-      min_rank(desc(!!wt)) <= .n
-    } else {
-      min_rank(!!wt) <= abs(.n)
-    }
-  }))
-  filter(x, !!pred)
+  filter(x, top_n_rank({{ n }}, !!wt))
+}
+
+top_n_rank <- function(n, wt) {
+  if (n > 0) {
+    min_rank(desc(wt)) <= n
+  } else {
+    min_rank(wt) <= abs(n)
+  }
 }
 
 #' @export
 #' @rdname top_n
 top_frac <- function(x, n, wt) {
-  top_n(x, !!enquo(n) * n(), !!enquo(wt))
+  top_n(x, {{ n }} * n(), {{ wt }})
 }