Swaggadocio

Sat07Aug

Stabby Lambdas & Curried Functions
Starting a new project at work in Ruby 1.9, I noticed there is a new syntax for creating lambdas:
```
a = ->(a,b) { a**b }
```
This is equivalent to the conventional
```
b = lambda { |a,b| a**b }
```
Thus:
```
a[2,5] == b[2,5]
```
My opinion is split on the aesthetic appeal of this new syntax, sure it’s brief but it’s also erlang-y. Fortunately it does have a useful feature, i.e. the ability to give default values to block parameter. This is not possible:
```
lambda { |a,b=2| a**b }
```
This is:
```
->(a,b=2) { a**b }
```
Currying, i.e. partial application of functions also appear
```
pow = ->(a,b) { a**b }.curry
=> #<Proc:0x00000100b021b8 (lambda)>
square = pow[2]
=> #<Proc:0x00000100aff2b0 (lambda)>
square[2]
=> 4
square[4]
=> 16
square[16]
=> 256
```
Proc#call has also been aliased as Proc#=== meaning one can use lambdas in case statements… WUUUUUTTT!

S