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Undesirable function linter

Source: R/undesirable_function_linter.R
undesirable_function_linter.Rd

Report the use of undesirable functions and suggest an alternative.

Usage

undesirable_function_linter(
  fun = default_undesirable_functions,
  symbol_is_undesirable = TRUE
)

Arguments

fun

Character vector of undesirable function names. Input can be any of three types:

  • Unnamed entries must be a character string specifying an undesirable function.

  • For named entries, the name specifies the undesirable function.

    • If the entry is a character string, it is used as a description of why a given function is undesirable

    • Otherwise, entries should be missing (NA) A generic message that the named function is undesirable is used if no specific description is provided. Input can also be a list of character strings for convenience.

Defaults to default_undesirable_functions. To make small customizations to this list, use modify_defaults().

symbol_is_undesirable

Whether to consider the use of an undesirable function name as a symbol undesirable or not.

See also

linters for a complete list of linters available in lintr.

Tags

best_practices, configurable, robustness, style

Examples

# defaults for which functions are considered undesirable
names(default_undesirable_functions)
#>  [1] ".libPaths"     "attach"        "browser"       "debug"        
#>  [5] "debugcall"     "debugonce"     "detach"        "library"      
#>  [9] "mapply"        "options"       "par"           "require"      
#> [13] "sapply"        "setwd"         "sink"          "source"       
#> [17] "structure"     "Sys.setenv"    "Sys.setlocale" "trace"        
#> [21] "undebug"       "untrace"      

# will produce lints
lint(
  text = "sapply(x, mean)",
  linters = undesirable_function_linter()
)
#> <text>:1:1: style: [undesirable_function_linter] Avoid undesirable function "sapply". As an alternative, use vapply() with an appropriate `FUN.VALUE=` argument to obtain type-stable simplification.
#> sapply(x, mean)
#> ^~~~~~

lint(
  text = "log10(x)",
  linters = undesirable_function_linter(fun = c("log10" = NA))
)
#> <text>:1:1: style: [undesirable_function_linter] Avoid undesirable function "log10".
#> log10(x)
#> ^~~~~

lint(
  text = "log10(x)",
  linters = undesirable_function_linter(fun = c("log10" = "use log()"))
)
#> <text>:1:1: style: [undesirable_function_linter] Avoid undesirable function "log10". As an alternative, use log().
#> log10(x)
#> ^~~~~

lint(
  text = 'dir <- "path/to/a/directory"',
  linters = undesirable_function_linter(fun = c("dir" = NA))
)
#> <text>:1:1: style: [undesirable_function_linter] Avoid undesirable function "dir".
#> dir <- "path/to/a/directory"
#> ^~~


lint(
  text = 'dir <- "path/to/a/directory"',
  linters = undesirable_function_linter(fun = "dir")
)
#> <text>:1:1: style: [undesirable_function_linter] Avoid undesirable function "dir".
#> dir <- "path/to/a/directory"
#> ^~~

# okay
lint(
  text = "vapply(x, mean, FUN.VALUE = numeric(1))",
  linters = undesirable_function_linter()
)
#> ℹ No lints found.

lint(
  text = "log(x, base = 10)",
  linters = undesirable_function_linter(fun = c("log10" = "use log()"))
)
#> ℹ No lints found.

lint(
  text = 'dir <- "path/to/a/directory"',
  linters = undesirable_function_linter(fun = c("dir" = NA), symbol_is_undesirable = FALSE)
)
#> ℹ No lints found.

lint(
  text = 'dir <- "path/to/a/directory"',
  linters = undesirable_function_linter(fun = "dir", symbol_is_undesirable = FALSE)
)
#> ℹ No lints found.