[Haskell-cafe] Using -> as both type and value constructor

[wren ng thornton]

On 8/24/11 5:03 PM, Armando Blancas wrote:
>>
>>> I didn't see that claim in the linked slides, and it's not Haskell '98
>> (nor Haskell 2010).
>
> I didn't realize it linked to the slides; I thought that pointed to the
> article. I just found another version of the paper, A Simple Implementation
> Technique for Priority Search Queues, by Hinze, which shows the binding type
> as a pair, with access functions for k and p. I'll continue to work my way
> through the material there. Thanks for you response.

With -XTypeOperators you can define

     data a :-> b = a :-> b

where (:->) is both a type constructor and a data constructor. Note the 
leading colon which is the only "capital" punctuation letter. Hinze may 
have just chosen to elide the colon for prettiness.

-- 
Live well,
~wren