Evaluate a regular map-reduce call with progress updates

Usage

progressify(
  expr,
  substitute = TRUE,
  ...,
  when = TRUE,
  eval = TRUE,
  envir = parent.frame()
)

Arguments

expr: An R expression.
substitute: If TRUE, expr is quoted.
when: If TRUE (default), the expression is progressified, otherwise not.
eval: If TRUE (default), the progressified expression is evaluated, otherwise it is returned.
envir: The environment in which expr is evaluated.
...: Not used.

Value

Returns the value of the evaluated expression expr.

Expression unwrapping

The transpilation mechanism includes logic to "unwrap" expressions enclosed in constructs such as !, { }, ( ), local(), I(), identity(), invisible(), suppressMessages(), suppressWarnings(), suppressPackageStartupMessages(), withCallingHandlers(), and with(). The transpiler descends through wrapping constructs until it finds a transpilable expression, avoiding the need to place progressify() inside such constructs. This allows for patterns like:

y <- {
  lapply(xs, fcn)
} |> suppressMessages() |> progressify()

avoiding having to write:

y <- {
  lapply(xs, fcn) |> progressify()
} |> suppressMessages()

Examples

handlers(global = TRUE) # listen to progress updates
#> Error in globalCallingHandlers(condition = global_progression_handler): should not be called with handlers on the stack

xs <- list(1, 1:2, 1:2, 1:5)
y <- lapply(X = xs, FUN = sum) |> progressify()
str(y)
#> List of 4
#>  $ : num 1
#>  $ : int 3
#>  $ : int 3
#>  $ : int 15