Incomprehensible syntax in Scala

Question

trait GenericCategory[->>[_, _]] { def id[A]: A ->> A def compose[A, B, C](g: B ->> C, f: A ->> B): A ->> C }

I can't figure out the syntax right next to the trait's name

[->>[_,_]]

possible duplicate of In Scala type parameters, what do ->> and ->>> mean? — om-nom-nom
– om-nom-nom, Commented Apr 10, 2013 at 13:05
As with methods of a single argument, generic types / type constructors of two arguments can be used in infix form. That probably makes the name a bit more sensible, since it is presumably meant to be used that way. — Randall Schulz
– Randall Schulz, Commented Apr 10, 2013 at 16:12

Community · Accepted Answer · 2017-05-23 12:33:58Z

8

The reason you might find it confusing is that ->> is the name for the higher-kinded type -- it might have as well been called Arrow instead.

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answered Apr 10, 2013 at 13:07

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1 Comment

Great references, would you mind to add this same answer to the original question referred to by @om-nom-nom?