Safely retrieves a named element from a list, returning a default value
if the element is missing or NULL.
Usage
get_param(args_list, param_name, default_value)
Arguments
- args_list
List to extract from.
- param_name
Character. Name of the element to retrieve.
- default_value
Default value to return if element is missing or
NULL.
Value
The value of args_list[[param_name]] if present and
non-NULL, otherwise default_value.