A.7.2 eval()

The Input Deck database can be told to evaluate an expression immediately while
parsing. This can be done using the `eval()` function, e.g.,

ext a = 10; ext b = 2; c = a * b; d = eval(c); // evaluated to 20

In this example the variables `a` and `b` are declared as extern
(see Section A.3) and can, therefore, be changed by the
simulator. Both variables are initialized. The variable `c` contains a
formula calculating the product of the variables `a` and `b`.
Variable `d` immediately calculates the result of variable `c` and,
from now on, stores a constant value. In contrast to variable `c` it
does no longer depend on any other variable. Each time variable `a` or
`b` is changed by the simulator variable `c` will change
automatically while variable `d` remains unchanged and keeps its
initialization value calculated once while parsing.

Robert Klima 2003-02-06