Question

1. What do you call the -> operator as in the following?

   ->(...) do
     ...
   end
   

2. Aren’t the following snippets equivalent?

   succ = ->(x) {x + 1}
   succ = lambda {|x| x + 1}
   

Answer 1

In Ruby Programming Language (“Methods, Procs, Lambdas, and Closures”), a lambda defined using -> is called lambda literal.

succ = ->(x){ x+1 }
succ.call(2)

The code is equivalent to the following one.

succ = lambda { |x| x + 1 }
succ.call(2)

Informally, I have heard it being called stabby lambda or stabby literal.