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Quietly Evaluate an Expression with Custom Warning Patterns

Source: R/general_quietly.R
quietly.Rd

Evaluates an R expression while suppressing package startup messages and selected warnings and messages. By default, warnings containing "was built under R version" or "Loading required namespace" are muffled. Additional patterns (regular expressions) can be provided via ... to suppress matching warnings or messages.

Usage

quietly(expr, ...)

Arguments

expr

An R expression to be evaluated quietly. This can be a single expression or a block of code wrapped in curly brackets.

...

Additional character strings. Each value will be treated as a regular expression pattern to match in warning or message text to muffle. For example, quietly(expr, "Picked up JAVA_TOOL_OPTIONS", "Scale for [xy] is already present\\.").

Value

The result of evaluating expr, with specified messages and warnings suppressed.

Author

Ahmed El-Gabbas

Examples

# Suppress a package startup message and a version warning
quietly({
  warning("This package was built under R version 4.3.1", call. = FALSE)
})
#> Warning: This package was built under R version 4.3.1
#> function (...) 
#> capture_output(.f(...))
#> <bytecode: 0x5583198c7e48>
#> <environment: 0x5583198c8120>

# Suppress a custom warning pattern (e.g., JAVA_TOOL_OPTIONS)
quietly({
 warning(
   "Picked up JAVA_TOOL_OPTIONS: -Djava.util.prefs.userRoot=/tmp/.java1234",
   call. = FALSE)
},
"Picked up JAVA_TOOL_OPTIONS")
#> Error in quietly({    warning("Picked up JAVA_TOOL_OPTIONS: -Djava.util.prefs.userRoot=/tmp/.java1234",         call. = FALSE)}, "Picked up JAVA_TOOL_OPTIONS"): unused argument ("Picked up JAVA_TOOL_OPTIONS")

# Suppress multiple custom warning patterns
quietly({
  warning("Couldn't flush user prefs", call. = FALSE)
  warning("java.util.prefs.FileSystemPreferences error", call. = FALSE)
},
"Couldn't flush user prefs", "java.util.prefs.FileSystemPreferences")
#> Error in quietly({    warning("Couldn't flush user prefs", call. = FALSE)    warning("java.util.prefs.FileSystemPreferences error", call. = FALSE)}, "Couldn't flush user prefs", "java.util.prefs.FileSystemPreferences"): unused arguments ("Couldn't flush user prefs", "java.util.prefs.FileSystemPreferences")

# Show that a non-matching warning still prints
quietly({
  warning("This is a normal warning and should be displayed", call. = FALSE)
},
"Picked up JAVA_TOOL_OPTIONS")
#> Error in quietly({    warning("This is a normal warning and should be displayed",         call. = FALSE)}, "Picked up JAVA_TOOL_OPTIONS"): unused argument ("Picked up JAVA_TOOL_OPTIONS")

# Use a code block with multiple lines, some of which trigger warnings
quietly({
  # suppressed by default
  warning("Loading required namespace: foo", call. = FALSE)
  # suppressed by default
  warning("was built under R version 4.3.0", call. = FALSE)
  # not suppressed, will be shown
  warning("Something else", call. = FALSE)
})
#> Warning: Loading required namespace: foo
#> Warning: was built under R version 4.3.0
#> Warning: Something else
#> function (...) 
#> capture_output(.f(...))
#> <bytecode: 0x5583198c7e48>
#> <environment: 0x5583197334b0>

if (FALSE) {
  # Error if ... is not character
  quietly({ warning("test", call. = FALSE) }, 1L)

  # Error if expr is not a language object
  quietly("not an expression")
}

# Suppress specific messages using regular expression patterns
quietly({
  message("Scale for y is already present.")
  message("Scale for x is already present.")
  message("TTT")
  warning("Something else")
},
"Scale for [xy] is already present\\."
)
#> Error in quietly({    message("Scale for y is already present.")    message("Scale for x is already present.")    message("TTT")    warning("Something else")}, "Scale for [xy] is already present\\."): unused argument ("Scale for [xy] is already present\\.")