Package 'wrappr'

Title: A Collection of Helper and Wrapper Functions
Description: Helper functions to easily add functionality to functions. The package can assign functions to have an lazy evaluation allowing you to save and update the arguments before and after each function call. You can set a temporary working directory within functions and wrap console messages around other functions.
Authors: John Piper [aut, cre]
Maintainer: John Piper <[email protected]>
License: MIT + file LICENSE
Version: 0.1.0
Built: 2024-12-13 06:54:02 UTC
Source: CRAN

Help Index

Checks if variable exists in environment and returns back or creates a new variable

Description

Checks if variable exists in environment and returns back or creates a new variable

Usage

get_cache_or_create(
  var,
  func,
  ...,
  exists_func_args = NA,
  get_func_args = NA,
  warning_msg = NA_character_
)

Arguments

var

character. The name of the variable to check in the global environment.
func

function. A function that returns a value.
...

Additional arguments to be passed to the param func.
exists_func_args

list. A list of arguments to use in base::exists.
get_func_args

list. A list of arguments to use in bass::get.
warning_msg

character. Message sent to stop function if an error occurs.

Value

Unknown. The return type from the param func or the existing variable in global environment.

Examples

## Not run: 
df <- data.frame(col_1 = c("a","b","c"), col_2 = c(1,2,3))

create_blank_df <- function() {

    data.frame(col_1 = NA_character_, col_2 = NA_integer_)

    }

df_1 <- get_cache_or_create(
                          "df",
                          create_blank_df
                          )

df_2 <- get_cache_or_create(
                          "df_2",
                          create_blank_df
                          )

## End(Not run)

save and Delay a function call with the option to change the function and arguments when called

Description

save and Delay a function call with the option to change the function and arguments when called

Usage

lazy_eval(..., .f)

Arguments

...

Additional arguments to be passed to the param .f. Also in closure function returned.
.f

function. A function that will be called when needed. Also in closure function returned.

Value

closure function with same param names plus the param names overwrite_args Boolean and return_new_closure Boolean.

Examples

numbers <- c(1,2,3,4,5)

func <- lazy_eval(numbers, .f = sum)

sum_result <- func()

max_result <- func(.f = max)

mean_result <- func(.f = mean)

range_result <- func(.f = function(...) { max(...) - min(...)})

add_more_num_result <- func(4,5,6, NA, na.rm = TRUE)

updated_func <- func(na.rm = TRUE, return_new_closure = TRUE)

updated_func_result <- updated_func()

Wraps a message before and/or after a function

Description

Wraps a message before and/or after a function

Usage

msg_wrap(
  func,
  ...,
  before_func_msg = "",
  after_func_msg = "",
  print_func = print,
  use_msg = "both",
  print_return_var = FALSE
)

Arguments

func

function.
...

Additional arguments to be passed into the param func.
before_func_msg

character.
after_func_msg

character.
print_func

function. The default is print. Can use related function like message.
use_msg

character. The default is "both". Selects which messages to print in the function. Use before, after, both or none.
print_return_var

Boolean. The default is FALSE. Prints the output from the called func using the print argument from param print_func.

Value

Unknown. The return type from the param func.

Examples

numbers <- c(1,2,3,4,5)

answer <- msg_wrap(
                   sum,
                   numbers,
                   before_func_msg = "Currently summing the numbers",
                   after_func_msg = "Summing the numbers complete"
                   )

numbers_with_na <- c(1,2,3,NA,5)

answer_na_removed <- msg_wrap(
                              sum,
                              numbers,
                              na.rm = TRUE,
                              before_func_msg = "Sum with na.rm set to TRUE",
                              use_msg = "before"
                              )

numbers_to_sum <- c(10,20,30)

msg_wrap((function(x) sum(x[x%%2 == 1])),
         x = numbers_to_sum,
         before_func_msg = "Result from sum of odd numbers",
         use_msg = "before",
         print_return_var = TRUE
         )

Sets a temporary working directory within the function scope

Description

Sets a temporary working directory within the function scope

Usage

set_temp_wd(
  temp_cwd,
  func,
  ...,
  err_msg = "An error has occured in the function set_temp_wd"
)

Arguments

temp_cwd

character. Folder path to temporarily set the working directory
func

function. A function that used a directory path
...

Additional arguments to be passed to the param func.
err_msg

character. Message sent to stop function if an error occurs.

Value

Unknown. The return type from the param func.

Examples

## Not run: 

temp_wd <- "example/folder/address/to/change"

get_data <- set_temp_wd(temp_wd, read.csv, file = "file.csv")


## End(Not run)