Author new functions that stops and provides a custom message when a predicate evaluates to true.
brake_ff(predicate, stop_message, arguments)
| predicate | Evaluating function.  | 
    
|---|---|
| stop_message | Message to receive with the   | 
    
| arguments | (option) character vector of arguments for the new function. If missing, the new function will not have any arguments. Arguments in the   | 
    
Assigned function
parse_expr,missing_arg
map,set_names
Other ff functions: 
flag_ff()