What do you call the -> operator in Ruby?

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}
   

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.

=> == Hash Rocket

Separates keys from values in a hash map literal.

-> == Dash Rocket

Used to define a lambda literal in Ruby 1.9.X (without args) and Ruby 2.X (with args). The examples you give (->(x) { x * 2 } & lambda { |x| x * 2 }) are in fact equivalent.

Lambda rocket

I got that from this article. But first a google search for ruby lambda shorthand http://ruby-journal.com/becareful-with-space-in-lambda-hash-rocket-syntax-between-ruby-1-dot-9-and-2-dot-0/

->(x) { ... } is the same as lambda { |x| ... }. It creates a lambda. See Kernel#lambda A lambda is a type of proc, one that ensures the number of parameters passed to it is correct. See also Proc::new and Kernel#proc.