Higher Order Magic
In general you can usually work out an infix operator from it's type. To get it's type, type it into PolyML. But here are a few commonly used things...
Piping (right-to-left)
This is just function composition. You can think of it as: do the thing on the right then give the result back to the thing on the left. It pipes information from right to left.
o : ('b -> 'c) * ('a -> 'b) -> ('a -> 'c)
(f o g) x = f (g x)
Piping (2 on the right-to-left)
This is for when you want to give two things given to the right function before giving the result to the thing on the left:
oo
Piping (left-to-right)
|>
Piping (2 on the left-to-right)
#>
Piping (second left-to-right)
||>