EVL Functions
As an ‘EVL value’ in anon-config file, arbitrary EVL functions and expressions can be used. An input field is represented as ‘IN’.
All functions can be used in two ways:
- with pointers (preferred)
- without pointers (i.e. as referenced values, “with star”)
Option with pointers is preferred as it can handle NULL values (‘nullptr’ in fact). So these two examples:
str_function(IN) str_function(*IN)
are basically the same, but the first one might fail in case of using some standard C++ function and NULL value arrive. All EVL functions handle NULLs and (mostly) returns also NULL, so use ‘IN’ for them. In all other cases use better ‘*IN’.
There are these two rules in all EVL string manipulation functions described in this section:
- When the first argument is a pointer, the function returns also a pointer.
- When the first argument is ‘nullptr’, the function returns ‘nullptr’ as well.