CTL1 offers two functions that enable inline evaluation of a string as if it were CTL code. This way you can interpret text that is e.g stored somewhere in a database as code.
eval(string) - executes the
string as CTL code
eval_exp(string) -
evaluates the
string as a CTL expression (same as in eval(string))
and then returns the value
of the result. The value can be saved to a variable.
When using the functions, keep in mind only valid CTL code should be passed to them. So you have to use proper identificators and even terminate expressions with a semicolon. The evaluated expression has a limited scope and cannot see variables declared outside of it.
Example 61.2. Eval() Function Examples
Example 1:
int value = eval_exp("2+5"); // the result of the expression is stored to 'value'
Example 2:
int out; // the variable has to be declared as global
function transform() {
eval("out = 3 + 5;");
print_err(out);
$0.Date := $0.DATE;
return ALL
}