Batteries user guide : BatSeq.Infix

`sig val ( -- ) : int -> int -> int BatSeq.t val ( --^ ) : int -> int -> int BatSeq.t val ( --. ) : float * float -> float -> float BatSeq.t val ( --- ) : int -> int -> int BatSeq.t val ( --~ ) : char -> char -> char BatSeq.t val ( // ) : 'a BatSeq.t -> ('a -> bool) -> 'a BatSeq.t val ( /@ ) : 'a BatSeq.t -> ('a -> 'b) -> 'b BatSeq.t val ( @/ ) : ('a -> 'b) -> 'a BatSeq.t -> 'b BatSeq.t val ( //@ ) : 'a BatSeq.t -> ('a -> 'b option) -> 'b BatSeq.t val ( @// ) : ('a -> 'b option) -> 'a BatSeq.t -> 'b BatSeq.t end`