Merge pull request #92 from mlr-org/feat/dict-prototype

feat: allow prototype arguments

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: mlr3misc
 Title: Helper Functions for 'mlr3'
-Version: 0.12.0-9000
+Version: 0.13.0-9000
 Authors@R: c(
     person("Michel", "Lang", , "[email protected]", role = c("cre", "aut"),
            comment = c(ORCID = "0000-0001-9754-0393")),

NEWS.md

@@ -1,6 +1,8 @@
-# mlr3misc 0.13.0
+# mlr3misc 0.13.0-9000
 
-* Bugfix: disable leanification when `ROXYGEN_PKG` environment variable is set
+* Added the possibility to include prototype arguments when adding elements to a `Dictionary`
+* Removed unused argument `required_args` from `Dictionary` class
+* Disable leanification when `ROXYGEN_PKG` environment variable is set
 
 # mlr3misc 0.13.0
 

R/Dictionary.R

@@ -91,10 +91,19 @@ Dictionary = R6::R6Class("Dictionary",
     #' @param ... (`any`)\cr
     #' Passed down to constructor.
     #'
+    #' @param .prototype (`logical(1)`)\cr
+    #'   Whether to construct a prototype object.
+    #'
     #' @return Object with corresponding key.
-    get = function(key, ...) {
+    get = function(key, ..., .prototype = FALSE) {
       assert_string(key, min.chars = 1L)
-      dictionary_get(self, key, ...)
+      assert_flag(.prototype)
+      args = list(...)
+      if (.prototype) {
+        args = insert_named(self$prototype_args(key), args)
+      }
+
+      invoke(dictionary_get, self = self, key = key, .args = args)
     },
 
     #' @description
@@ -115,7 +124,6 @@ Dictionary = R6::R6Class("Dictionary",
     #' @description
     #' Adds object `value` to the dictionary with key `key`, potentially overwriting a previously stored item.
     #' Additional arguments in `...` must be named and are passed as default arguments to `value` during construction.
-    #' The names of all additional arguments which are mandatory for construction and missing in `...` should be listed in `required_args`.
     #'
     #' @param key (`character(1)`).
     #'
@@ -124,16 +132,18 @@ Dictionary = R6::R6Class("Dictionary",
     #' @param ... (`any`)\cr
     #' Passed down to constructor.
     #'
-    #' @param required_args (`character()`).
+    #' @param .prototype_args (`list()`)\cr
+    #'   List of arguments to construct a prototype object.
+    #'   Can be used when objects have construction arguments without defaults.
     #'
     #' @return `Dictionary`.
-    add = function(key, value, ..., required_args = character()) {
+    add = function(key, value, ..., .prototype_args = list()) {
       assert_string(key, min.chars = 1L)
       assert(check_class(value, "R6ClassGenerator"), check_r6(value), check_function(value))
-      assert_character(required_args, any.missing = FALSE)
 
       dots = assert_list(list(...), names = "unique", .var.name = "additional arguments passed to Dictionary")
-      assign(x = key, value = list(value = value, pars = dots, required_args = required_args), envir = self$items)
+      assert_list(.prototype_args, names = "unique", .var.name = "prototype arguments")
+      assign(x = key, value = list(value = value, pars = dots, prototype_args = .prototype_args), envir = self$items) # nolint
       invisible(self)
     },
 
@@ -154,15 +164,15 @@ Dictionary = R6::R6Class("Dictionary",
     },
 
     #' @description
-    #' Returns the names of arguments required to construct the object.
+    #' Returns the arguments required to construct a simple prototype of the object.
     #'
     #' @param key (`character(1)`)\cr
     #'   Key of object to query for required arguments.
     #'
-    #' @return `character()` of names of required arguments.
-    required_args = function(key) {
+    #' @return `list()` of prototype arguments
+    prototype_args = function(key) {
       assert_string(key, min.chars = 1L)
-      self$items[[key]][["required_args"]]
+      self$items[[key]][["prototype_args"]]
     }
   )
 )
@@ -184,10 +194,6 @@ dictionary_retrieve_item = function(self, key) {
 dictionary_initialize_item = function(key, obj, cargs = list()) {
   cargs = c(cargs[is.na(names2(cargs))],
     insert_named(obj$pars, cargs[!is.na(names2(cargs))]))
-  ii = wf(obj$required_args %nin% names(cargs))
-  if (length(ii)) {
-    stopf("Need argument '%s' to construct '%s'", obj$required_args[ii], key)
-  }
 
   constructor = obj$value
   if (inherits(constructor, "R6ClassGenerator")) {

tests/testthat/test_Dictionary.R

@@ -31,17 +31,6 @@ test_that("Dictionary clones R6", {
   expect_false(data.table::address(foo) == data.table::address(d$get("f")))
 })
 
-test_that("Dictionary required args", {
-  foo = R6Class("Foo", public = list(x = 0))
-  x = Dictionary$new()
-  x$add("a", foo)
-  x$add("b", foo, required_args = "c")
-
-  expect_equal(x$required_args("a"), character())
-  expect_equal(x$required_args("b"), "c")
-  expect_equal(x$required_args("c"), NULL)
-})
-
 test_that("Dictionary throws exception on unnamed args", {
   foo = R6Class("Foo", public = list(x = 0))
   x = Dictionary$new()
@@ -128,3 +117,14 @@ test_that("avoid unintended partial argument matching", {
   expect_r6(a, "A")
   expect_equal(a$d, 1)
 })
+
+
+test_that("prototype_args works", {
+  A = R6Class("A", public = list(x = NULL, initialize = function(x) self$x = x))
+  d = Dictionary$new()
+  d$add("a", A, .prototype_args = list(x = 1))
+  expect_identical(d$prototype_args("a"), list(x = 1))
+  a = d$get("a", .prototype = TRUE)
+  expect_identical(a$x, 1)
+  expect_identical(d$prototype_args("a"), list(x = 1))
+})