twitter/algebird — pull request #366 by MansurAshraf (2014-12-03 23:28:21+00:00)
Title: add no-arg count method to aggregator

Trying to write some scalding example that shows scalding equivalent of SQL code using Aggregator.

so for this SQL statement

```
SELECT customerName, Count(*)
FROM order
GroupBy customerName
```

I have to write something like this

```
val orders = List(
Order(1, "12/22/2005", 160, 2, "Smith"),
Order(2, "08/10/2005", 190, 2, "Johnson"),
Order(3, "07/13/2005", 500, 5, "Baldwin"),
Order(4, "07/15/2005", 420, 2, "Smith"),
Order(5, "12/22/2005", 1000, 4, "Wood"),
Order(6, "10/2/2005", 820, 4, "Smith"),
Order(7, "11/03/2005", 2000, 2, "Baldwin"))

TypedPipe.from(orders)
.groupBy(_.customerName)
.aggregate(count( x => true))
```

it would be nice if we could just write

```
TypedPipe.from(orders)
.groupBy(_.customerName)
.aggregate(count)
```