comma.list: Print out comma separated list of values in X, truncating if many (good for error messages)
Description
Often for nice presentation of error messages you wish to display a list of values.
This adds commas between entries and will truncate the list above a length of 50
items with an ellipsis. Very simple but convenient function.
Usage
comma.list(X)
Value
string with entries separated by commas, and if long, entries skipped
indicated by an ellipsis.