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Utilities: cat_*() functions

Source: R/utils-cat.R
cat_.Rd

cat_*() functions control user output in patter functions with the .verbose argument.

Usage

cat_setup(.fun, .verbose)

cat_init(.verbose)

cat_log_file(.verbose)

Arguments

.fun

A character string that defines the name of the parent function.

.verbose

A logical variable or a string that defines the path to a text file.

  • .verbose = FALSE suppresses user outputs;

  • .verbose = TRUE sends user outputs to the console;

  • .verbose = file.path("path", "to", "text", "file.txt") sends user outputs to a .txt file;

Details

These are internal functions.

  • cat_setup() sets up messages within functions;

  • cat_init() defines a cat() wrapper based on .verbose;

  • cat_log_file() validates .verbose and, if necessary, creates the .txt file;

Author

Edward Lavender

Examples

if (FALSE) { # \dontrun{

# Define example function
wrap <- function(.verbose = getOption("Patter.verbose")) {
  # Set up messages and exit handler
  cats <- cat_setup(.fun = "wrap", .verbose = .verbose)
  on.exit(eval(cats$exit, envir = cats$envir), add = TRUE)
  # Run function
  cats$cat("Running function...")
  Sys.sleep(1)
}

# `.verbose = TRUE` sends user output to the console
wrap(.verbose = TRUE)

# `.verbose = {log}.txt` sends user output to file
log.txt <- tempfile(fileext = ".txt")
wrap(.verbose = log.txt)
readLines(log.txt)
unlink(log.txt)

# `.verbose = TRUE` suppresses user output
wrap(.verbose = FALSE)
} # }