added methods for dplyr::slice_*(), closes #84

NAMESPACE

@@ -69,6 +69,11 @@ S3method(semi_join,egor)
 S3method(setdiff,egor)
 S3method(setequal,egor)
 S3method(slice,egor)
+S3method(slice_head,egor)
+S3method(slice_max,egor)
+S3method(slice_min,egor)
+S3method(slice_sample,egor)
+S3method(slice_tail,egor)
 S3method(subset,egor)
 S3method(summarise,egor)
 S3method(summarize,egor)

R/dplyr_methods.R

@@ -211,6 +211,47 @@ slice.egor <- function(.data, ...) {
   return_egor_with_result(.data, result)
 }
 
+#' @export
+#' @noRd
+#' @method slice_head egor
+slice_head.egor <- function(.data, ...) {
+  result <- slice_head(tibble_egos(.data)[[attr(.data, "active")]], ...)
+  return_egor_with_result(.data, result)
+}
+
+#' @export
+#' @noRd
+#' @method slice_tail egor
+slice_tail.egor <- function(.data, ...) {
+  result <- slice_tail(tibble_egos(.data)[[attr(.data, "active")]], ...)
+  return_egor_with_result(.data, result)
+}
+
+#' @export
+#' @noRd
+#' @method slice_min egor
+slice_min.egor <- function(.data, ...) {
+  result <- slice_min(tibble_egos(.data)[[attr(.data, "active")]], ...)
+  return_egor_with_result(.data, result)
+}
+
+
+#' @export
+#' @noRd
+#' @method slice_max egor
+slice_max.egor <- function(.data, ...) {
+  result <- slice_max(tibble_egos(.data)[[attr(.data, "active")]], ...)
+  return_egor_with_result(.data, result)
+}
+
+#' @export
+#' @noRd
+#' @method slice_sample egor
+slice_sample.egor <- function(.data, ...) {
+  result <- slice_sample(tibble_egos(.data)[[attr(.data, "active")]], ...)
+  return_egor_with_result(.data, result)
+}
+
 
 # group_by count tally summarise ------------------------------------------
 

tests/testthat/test-dplyr_methods.R

@@ -44,6 +44,9 @@ test_that("methods for dplyr are working",
               egor::activate(e, "alter") %>%
                 filter(sex == "w")
 
+
+              # slice and slice_* -------------------------------------
+
               slice(e, 1)
 
               activate(e, alter) %>%
@@ -52,6 +55,48 @@ test_that("methods for dplyr are working",
               activate(e, aatie) %>%
                 slice(1:2)
 
+              slice_head(e, n = 1)
+
+              activate(e, alter) %>%
+                slice_head() # defaults to n = 1
+
+              activate(e, aatie) %>%
+                slice_head(prop = .2)
+
+              slice_tail(e, n = 1)
+
+              activate(e, alter) %>%
+                slice_tail() # defaults to n = 1
+
+              activate(e, aatie) %>%
+                slice_tail(prop = .2)
+
+              slice_min(e, age.years, n = 2)
+
+              activate(e, alter) %>%
+                slice_min(age.years) # defaults to n = 1
+
+              activate(e, aatie) %>%
+                slice_min(weight, prop = .2)
+
+              slice_max(e, age.years, n = 1)
+
+              activate(e, alter) %>%
+                slice_max(age.years) # defaults to n = 1
+
+              activate(e, aatie) %>%
+                slice_max(weight, prop = .2)
+
+              slice_sample(e, n = 1)
+
+              activate(e, alter) %>%
+                slice_sample() # defaults to n = 1
+
+              activate(e, aatie) %>%
+                slice_sample(prop = .01)
+
+              # summarise ----------------------------------------------
+
               e %>%
                 activate("alter") %>%
                 group_by(.egoID) %>%