[burlesona]

You can literally write my_method = Kernel.method(:puts) and it’ll give you the method to do what you wish with.

As far as defining anonymous functions, literally all you have to do is:

my_func = -> (input) { output }

That makes a “lambda” which is literally just a function you can pass around anonymously.

You call it via either my_func.call(input) or simply my_func[input].

That capability is used all over the place.

Ruby absolutely has first class functions, the only thing you can say is it the syntax is slightly different if you want to use them anonymously (with no object context).

[jablan]

> my_method = Kernel.method(:puts)

That's exactly what being first-class is not. You tell Kernel to wrap you a method called puts into an object of class Method, rather than assigning a method to a variable. You don't have to look further than JS for a counterexample.

[burlesona]

Ruby has two kinds of functions. Methods are functions attached to objects. Lambdas are functions that are not. Ruby lambdas are exactly like javascript arrow functions, or python functions.

There's a _reason_ for the difference, since it determines the implicit self, which is a meaningful part of how Ruby works. Because that difference is meaningful it is reflected in the syntax. `lambda`, or the shorthand `->` creates a function not attached to an object, and `def` creates a function and attaches it to the calling context (making it a method).

Perhaps you don't like this, that's fine. But to say "nope I want my methods and functions to be interchangeable and not to be called lambdas" is purely a subjective argument.

Objectively, Ruby has first-class functions that can be assigned to variables and passes around and returned from other function calls etc etc. They're just called lambdas.

[jonnytran]

This is clearly a misunderstanding of what a first-class function is. If it doesn't meet your criteria in the colloquial sense of "first-class", that's one thing. But in computer science and programming in general, "first-class function" has a very specific meaning [1], and Ruby absolutely meets the criteria.

The other bit of confusion is that the actual syntax in Ruby optimizes for the common case, which is calling methods. Yehuda Katz wrote a good article explaining this [2]. Among other things, it allows you to create very concise DSLs in Ruby that would never be quite as clean in Python.

1: https://en.wikipedia.org/wiki/First-class_function

2: https://yehudakatz.com/2010/02/21/ruby-is-not-a-callable-ori...