Proposal: Add Compositor class as superclass of Arrow

Philippa Cowderoy flippa at
Thu Oct 18 15:58:27 EDT 2007

On Wed, 17 Oct 2007, Ashley Yakeley wrote:

> Conal Elliott wrote:
> > DeepArrow could benefit from suggestions (perhaps refactoring), and I
> > would appreciate such input.  In any case, I imagine there's some rich,
> > useful structure between Category & Arrow, and now would be a great time
> > to explore it before settling on a new class hierarchy.
> The only class that comes to mind is a subclass of Category that has arr
> but not first.

The other way round (first but not arr) is arguably more useful - it's the 
class of embedded first-order compositional languages and with a small 
amount of work we can even define applicative sugar akin to proc or do. 
There are all kinds of tasks that can be a big win for!

flippa at

There is no magic bullet. There are, however, plenty of bullets that
magically home in on feet when not used in exactly the right circumstances.

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