[Gambas-user] gb2 Eval() question

[tobias]

hi,
i've been playing around with Eval() for some days, i read that it 
evaluates only expressions so i understand that DIMs raise "unexpected 
DIM" but what about SHELL and EXEC which also raise "unexpected ..." 
what is the difference between
Eval("hProcVar = SHELL \"zenity --info --text hello\" WAIT", hVarCollection)
and
Eval("iIntVar = 5 * 6", hVarCollection)?
I think both are assignments to variables and thus expressions? (The 
same with DIM Var AS Integer = 7 but which I think just tells to make 
room for a variable and initialises it so isn't an expression, right?)
I found nothing else in gb.eval Expression class than "You can use 
almost any Gambas subroutines and operators."
What are the criteria of a gambas expression?

best regards,
tobi