-val delay : faust_exp -> int, returns the number of delays estimated staticly.
-Attention: delays of "@" is estimated as 10 constant,
-delays of "vectorize" and "serialize" haven't been implemented,
-delays of "rdtable" hasn't been implemented.
-
-val d_seq : int * int -> int * int -> int * int, process dimension for constructor "seq(:)",
-which is (size of input beam of first exp, size of output beam of second exp)
-along with beam matching.
-
-val d_split : int * int -> int * int -> int * int, process dimension for constructor "split(<:)",
-which is (size of input beam of first exp, size of output beam of second exp)
-along with beam matching.
-
-val d_merge : int * int -> int * int -> int * int, process dimension for constructor "merge(:>)",
-which is (size of input beam of first exp, size of output beam of second exp)
-along with beam matching.
-
-val d_rec : int * int -> int * int -> int * int, process dimension for constructor "rec(~)",
-which is (size of input beam of first exp - size of output beam of second exp,
-size of output beam of first exp)
-along with beam matching.
-