Add "which" to filtering verbs (#17)

NEWS.md

@@ -2,6 +2,7 @@
 
 - `distinct` gained `.keep_all` and `.keep_old` parameters.
 - `filter_on` now allows empty names for data tables that already have keys (#17).
+- All filtering verbs now have a `which` parameter (#17).
 
 # table.express 0.2.0
 

R/VERBS-filter_on.R

@@ -3,13 +3,12 @@
 #' Helper to filter specifying the `on` part of the [data.table::data.table] query.
 #'
 #' @export
-#' @importFrom rlang abort
 #' @importFrom rlang expr
 #'
 #' @template data-arg
 #' @param ... Key-value pairs, maybe with empty keys if the `data.table` already has them. See
 #'   details.
-#' @param nomatch,mult See [data.table::data.table].
+#' @param which,nomatch,mult See [data.table::data.table].
 #' @param .negate Whether to negate the expression and search only for rows that don't contain the
 #'   given values.
 #' @template chain-arg
@@ -32,8 +31,8 @@
 #'     start_expr %>%
 #'     filter_on(cyl = 4, gear = 5)
 #'
-filter_on <- function(.data, ..., nomatch = getOption("datatable.nomatch"), mult = "all", .negate = FALSE,
-                      .chain = getOption("table.express.chain", TRUE))
+filter_on <- function(.data, ..., which = FALSE, nomatch = getOption("datatable.nomatch"), mult = "all",
+                      .negate = FALSE, .chain = getOption("table.express.chain", TRUE))
 {
     key_value <- parse_dots(FALSE, ...)
     keys <- names(key_value)
@@ -49,6 +48,9 @@ filter_on <- function(.data, ..., nomatch = getOption("datatable.nomatch"), mult
     if (all(nzchar(keys))) {
         frame_append(ans, on = !!keys, .parse = FALSE)
     }
+    if (!missing(which)) {
+        frame_append(ans, which = !!which, .parse = FALSE)
+    }
     if (!missing(nomatch)) {
         frame_append(ans, nomatch = !!nomatch, .parse = FALSE)
     }

R/VERBS-filter_sd.R

@@ -10,13 +10,15 @@
 #' @importFrom rlang enexpr
 #' @importFrom rlang enquo
 #' @importFrom rlang expr
+#' @importFrom rlang maybe_missing
 #' @importFrom rlang syms
 #' @importFrom rlang zap
 #'
 #' @template data-arg
 #' @param .SDcols See [data.table::data.table] and the details here.
 #' @param .how The filtering function or predicate.
 #' @param ... Possibly more arguments for `.how`.
+#' @param which Passed to [data.table::data.table].
 #' @param .collapse See [where-table.express].
 #' @template parse-arg
 #' @template chain-arg
@@ -37,7 +39,7 @@
 #'     start_expr %>%
 #'     filter_sd(c("vs", "am"), .COL == 1)
 #'
-filter_sd <- function(.data, .SDcols, .how = Negate(is.na), ..., .collapse = `&`,
+filter_sd <- function(.data, .SDcols, .how = Negate(is.na), ..., which, .collapse = `&`,
                       .parse = getOption("table.express.parse", FALSE),
                       .chain = getOption("table.express.chain", TRUE))
 {
@@ -58,7 +60,8 @@ filter_sd <- function(.data, .SDcols, .how = Negate(is.na), ..., .collapse = `&`
 
     clauses <- Map(substitue_col_pronoun, list(.how), rlang::syms(.SDcols))
 
-    where(.data, !!!clauses, .collapse = !!rlang::enexpr(.collapse), .parse = FALSE, .chain = .chain)
+    where(.data, !!!clauses, which = rlang::maybe_missing(which), .collapse = !!rlang::enexpr(.collapse),
+          .parse = FALSE, .chain = .chain)
 }
 
 #' @importFrom rlang as_label

R/VERBS-where.R

@@ -16,8 +16,10 @@ where <- function(.data, ...) {
 #' @rdname where-table.express
 #' @export
 #' @importFrom rlang enquo
+#' @importFrom rlang is_missing
 #' @importFrom rlang quo_get_expr
 #'
+#' @param which Passed to [data.table::data.table].
 #' @param .collapse A boolean function which will be used to "concatenate" all conditions in `...`.
 #' @template parse-arg
 #' @template chain-arg
@@ -32,7 +34,7 @@ where <- function(.data, ...) {
 #'     start_expr %>%
 #'     where(vs == 0, am == 1)
 #'
-where.ExprBuilder <- function(.data, ..., .collapse = `&`,
+where.ExprBuilder <- function(.data, ..., which = FALSE, .collapse = `&`,
                               .parse = getOption("table.express.parse", FALSE),
                               .chain = getOption("table.express.chain", TRUE))
 {
@@ -52,5 +54,10 @@ where.ExprBuilder <- function(.data, ..., .collapse = `&`,
         clause <- reduce_expr(clause[-1L], first_where, .collapse, .parse = .parse)
     }
 
-    .data$set_where(clause, .chain)
+    .data <- .data$set_where(clause, .chain)
+    if (!rlang::is_missing(which)) {
+        frame_append(.data, which = !!which, .parse = FALSE)
+    }
+
+    .data
 }

inst/NEWS.md

@@ -2,3 +2,4 @@
 
 - `distinct` gained `.keep_all` and `.keep_old` parameters.
 - `filter_on` now allows empty names for data tables that already have keys.
+- All filtering verbs now have a `which` parameter.

tests/testthat/unit/test-filter.R

@@ -139,3 +139,9 @@ test_that("The filter verb works with several values per key for primary keys.",
 
     expect_identical(ans, expected)
 })
+
+test_that("Filtering when passing which = TRUE works.", {
+    expected <- DT[cyl == 6 & mpg > 20, which = TRUE]
+    ans <- DT %>% start_expr %>% filter(cyl == 6, mpg > 20, which = TRUE) %>% end_expr
+    expect_identical(ans, expected)
+})

tests/testthat/unit/test-filter_on.R

@@ -59,3 +59,9 @@ test_that("The filter_on verb works for several values per key.", {
 
     expect_identical(ans, expected)
 })
+
+test_that("The filter_on verb works when which = TRUE.", {
+    expected <- data.table::copy(DT)[.(1, 0), on = c("vs", "am"), which = TRUE]
+    ans <- DT %>% start_expr %>% filter_on(vs = 1, am = 0, which = TRUE) %>% end_expr(.by_ref = FALSE)
+    expect_identical(ans, expected)
+})

tests/testthat/unit/test-filter_sd.R

@@ -55,3 +55,9 @@ test_that("Filtering SD with :-calls works.", {
     ans <- DT %>% start_expr %>% filter_sd(vs:9, .COL == 1) %>% end_expr
     expect_identical(ans, expected)
 })
+
+test_that("Filtering SD when which = TRUE works.", {
+    expected <- DT[vs == 1 & am == 1, which = TRUE]
+    ans <- DT %>% start_expr %>% filter_sd(vs:am, .COL == 1, which = TRUE) %>% end_expr
+    expect_identical(ans, expected)
+})