[sv-ac] checker: Clarification on functions & side effects

LRM states that Functions shall be automatic (or preserve no state
information) and have no side effects,
*
*
*1) What is a side effect? To me a side effect is an assignment of a
variable (free variable of the checker or a module).*
*A function can (in a checker) only return a value.   Thus the following is
illegal: *
*checker t_chk(...); *
*  logic a, x, y;*
* function void inc_a; *
*       a ++; // same as    a=a+1 // illegal blocking assignment? *
*     // a <= a+1;  // Illegal also, cannot change value of a variable*
*   endfunction : a_to_1*
* ap_test: assert property(@ (posedge clk) (x, inc_a()) |-> y) ;*
*endchecker : t_chk*
   --
* 2) Can **functions be of type void in a checker? *
   Since a void function must have a side effect, such as assigning a value
to a variable, I believe that they are illegal.
Function with return type of void cannot be used in/as an expression.


>
> * *
>

-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.