use NULL instead of identity()

and filter with purrr:::compact(). Requires breaking API change since initializer are now not a function anymore but a list of funcitons.

Author: lorenzwalthert

API

@@ -2,7 +2,7 @@
 
 ## Exported functions
 
-create_style_guide(initialize = default_style_guide_attributes, line_break = NULL, space = NULL, token = NULL, indention = NULL, use_raw_indention = FALSE, reindention = tidyverse_reindention())
+create_style_guide(initialize = lst(default_style_guide_attributes), line_break = NULL, space = NULL, token = NULL, indention = NULL, use_raw_indention = FALSE, reindention = tidyverse_reindention())
 default_style_guide_attributes(pd_flat)
 specify_math_token_spacing(zero = NULL, one = c("'+'", "'-'", "'*'", "'/'", "'^'"))
 specify_reindention(regex_pattern = NULL, indention = 0, comments_only = TRUE)

NAMESPACE

@@ -14,6 +14,7 @@ export(tidyverse_reindention)
 export(tidyverse_style)
 import(tibble)
 importFrom(magrittr,"%>%")
+importFrom(purrr,compact)
 importFrom(purrr,flatten)
 importFrom(purrr,flatten_chr)
 importFrom(purrr,flatten_int)

R/style_guides.R

@@ -71,7 +71,7 @@ tidyverse_style <- function(scope = "tokens",
 
       fix_quotes,
       remove_space_before_closing_paren,
-      if (strict) remove_space_before_opening_paren else identity,
+      remove_space_before_opening_paren = if (strict) remove_space_before_opening_paren,
       add_space_after_for_if_while,
       add_space_before_brace,
       remove_space_before_comma,
@@ -105,25 +105,21 @@ tidyverse_style <- function(scope = "tokens",
   line_break_manipulators <- if (scope >= "line_breaks") {
     lst(
       remove_line_break_before_curly_opening,
-      if (strict) remove_line_break_before_round_closing_after_curly else identity,
-      if (strict) remove_line_break_before_round_closing_fun_dec else identity,
+      remove_line_break_before_round_closing_after_curly =
+        if (strict) remove_line_break_before_round_closing_after_curly,
+      remove_line_break_before_round_closing_fun_dec =
+        if (strict) remove_line_break_before_round_closing_fun_dec,
       partial(style_line_break_around_curly, strict),
-      if (strict) {
+      set_line_break_after_opening_if_call_is_multi_line = if (strict)
         partial(
           set_line_break_after_opening_if_call_is_multi_line,
           except_token_after = "COMMENT",
           except_text_before = c("switch", "ifelse", "if_else")
-        )
-      } else {
-        identity
-      } ,
-      if (strict) {
+        ),
+      set_line_break_before_closing_call = if (strict)
         partial(
           set_line_break_before_closing_call, except_token_before = "COMMENT"
-        )
-      } else {
-        identity
-      } ,
+        ),
       remove_line_break_in_empty_fun_call,
       add_line_break_after_pipe
     )
@@ -135,20 +131,21 @@ tidyverse_style <- function(scope = "tokens",
       resolve_semicolon,
       add_brackets_in_pipe,
       remove_terminal_token_before_and_after,
-      if (strict) wrap_if_else_multi_line_in_curly else identity
+      wrap_if_else_multi_line_in_curly =
+        if (strict) wrap_if_else_multi_line_in_curly
     )
   }
 
 
   indention_modifier <-
-    c(
-      if (scope >= "indention") update_indention_ref_fun_dec,
-      identity
+    lst(
+      update_indention_ref_fun_dec = 
+        if (scope >= "indention") update_indention_ref_fun_dec
     )
 
   create_style_guide(
     # transformer functions
-    initialize        = default_style_guide_attributes,
+    initialize        = lst(default_style_guide_attributes),
     line_break        = line_break_manipulators,
     space             = space_manipulators,
     token             = token_manipulators,
@@ -166,7 +163,7 @@ tidyverse_style <- function(scope = "tokens",
 #' transformer function corresponds to one styling rule. The output of this
 #' function can be used as an argument for \code{style} in top level functions
 #' like [style_text()] and friends.
-#' @param initialize The bare name of a function that initializes various
+#' @param initialize A list of functions that initializes various
 #'   variables on each level of nesting.
 #' @param line_break A list of transformer functions that manipulate line_break
 #'   information.
@@ -188,8 +185,9 @@ tidyverse_style <- function(scope = "tokens",
 #'   create_style_guide(line_break = set_line_break_before_curly_opening)
 #' }
 #' style_text("a <- function(x) { x }", style = set_line_break_before_curly_opening_style)
+#' @importFrom purrr compact
 #' @export
-create_style_guide <- function(initialize = default_style_guide_attributes,
+create_style_guide <- function(initialize = lst(default_style_guide_attributes),
                                line_break = NULL,
                                space = NULL,
                                token = NULL,
@@ -206,7 +204,8 @@ create_style_guide <- function(initialize = default_style_guide_attributes,
     # transformer options
     use_raw_indention,
     reindention
-  )
+  ) %>%
+    map(compact)
 }