Merge pull request #127 from mlr-org/check_ops

Move `%check&&%` and `%check||%` from `mlr3pipelines`

DESCRIPTION

@@ -48,6 +48,7 @@ Collate:
     'calculate_hash.R'
     'capitalize.R'
     'catn.R'
+    'check_operators.R'
     'check_packages_installed.R'
     'chunk.R'
     'compose.R'

NAMESPACE

@@ -37,6 +37,8 @@ S3method(remove_named,default)
 S3method(remove_named,environment)
 S3method(strip_srcrefs,"function")
 S3method(strip_srcrefs,default)
+export("%check&&%")
+export("%check||%")
 export("%nin%")
 export("get_private<-")
 export(Callback)

NEWS.md

@@ -1,6 +1,7 @@
 # mlr3misc (development version)
 
 * feat: `as_callbacks()` returns a list named by the callback ids now.
+* feat: Added logical operators `%check&&%` and `%check||%` for `check_*`-functions from `checkmate` (moved here from `mlr3pipelines`).
 
 # mlr3misc 0.16.0
 

R/check_operators.R

@@ -0,0 +1,35 @@
+#' @title Logical Check Operators
+#'
+#' @description
+#' Logical AND and OR operators for `check_*`-functions from [`checkmate`][`checkmate::checkmate`].
+#'
+#' @param lhs,rhs (`function()`)\cr
+#'   `check_*`-functions that return either `TRUE` or an error message as a `character(1)`.
+#'
+#' @return Either `TRUE` or a `character(1)`.
+#'
+#' @name check_operators
+#' @examples
+#' library(checkmate)
+#'
+#' x = c(0, 1, 2, 3)
+#' check_numeric(x) %check&&% check_names(names(x), "unnamed")  # is TRUE
+#' check_numeric(x) %check&&% check_true(all(x < 0))  # fails
+#'
+#' check_numeric(x) %check||% check_character(x)  # is TRUE
+#' check_number(x) %check||% check_flag(x)  # fails
+NULL
+
+#' @export
+#' @rdname check_operators
+`%check&&%` = function(lhs, rhs) {
+  if (!isTRUE(lhs) && !isTRUE(rhs)) return(paste0(lhs, ", and ", rhs))
+  if (isTRUE(lhs)) rhs else lhs
+}
+
+#' @export
+#' @rdname check_operators
+`%check||%` = function(lhs, rhs) {
+  if (!isTRUE(lhs) && !isTRUE(rhs)) return(paste0(lhs, ", or ", rhs))
+  TRUE
+}

tests/testthat/test_check_operators.R

@@ -0,0 +1,13 @@
+test_that("check operators", {
+  # AND operator
+  expect_true(TRUE %check&&% TRUE)
+  expect_equal(TRUE %check&&% "error", "error")
+  expect_equal("error" %check&&% TRUE, "error")
+  expect_equal("error1" %check&&% "error2", "error1, and error2")
+
+  # OR operator
+  expect_true(TRUE %check||% TRUE)
+  expect_true(TRUE %check||% "error")
+  expect_true("error" %check||% TRUE)
+  expect_equal("error1" %check||% "error2", "error1, or error2")
+})