A progression condition represents a progress in an R program.
(character vector or a function) If a character vector, then
it is pasted together into a single string using an empty separator.
If a function, then the message is constructed by
calling this function with the progression condition
p itself as the
(numeric) The total amount of progress made.
(numeric) The step completed. If specified,
amount is ignored.
step should only be used when in full control of the
order when this progression condition is signaled. For example, it must not
be signaled as one of many parallel progress updates signaled concurrently,
because then we cannot guarantee the order these progressions arrive.
(POSIXct) A timestamp.
Type of progression made.
(character) Zero or more class names to prepend.
(character string) A character string that is unique for the current progressor and the current R session.
(integer) A non-negative integer that is incremented by one for each progression condition created.
(POSIXct or character string) A timestamp specifying when the progression condition was created.
(expression) A call expression.
(pairlist) The calls that lead up to this progression update.
(character string) A character string that is unique for the R session where the progressor was created.
Additional named elements.
A base::condition of class
To signal a progression condition, use