What can procs and lambdas do that functions can’t in ruby

I’ve been working in Ruby for the last couple weeks, and I’ve come to the subject of procs, lambdas and blocks. After reading a fair share of examples from a variety of sources, I don’t how they’re much different from small, specialized functions. It’s entirely possible that the examples I’ve read aren’t showing the power behind procs and lambdas.

C++11 support for higher-order list functions

Most functional programming languages (e.g. Common Lisp, Scheme / Racket, Clojure, Haskell, Scala, Ocaml, SML) support some common higher-order functions on lists, such as map, filter, takeWhile, dropWhile, foldl, foldr (see e.g. Common Lisp, Scheme / Racket, Clojure side-by-side reference sheet, the Haskell, Scala, OCaml, and the SML documentation.)

What triggered the popularity of lambda functions in modern mainstream programming languages?

In the last few years anonymous functions (AKA lambda functions) have become a very popular language construct and almost every major / mainstream programming language has introduced them or is planned to introduce them in an upcoming revision of the standard.

Type inference in Java 8

Is the introduction of the new lambda notation (see e.g. this article) in Java 8 going to require some kind of type inference?

Why doesn’t Haskell have type-level lambda abstractions?

Are there some theoretical reasons for that (like that the type checking or type inference would become undecidable), or practical reasons (too difficult to implement properly)?

What does this mean: Expression<Func>

In ASP.Net MVC, in the razor view, you can type this kind of code:

Is python lambda “really formal” λ-calculus or just share the name?

Now and then I use the Python lambda. Is it so formal that it is safe to say that you can do formal lambda calculus with it? I just used it but I didn’t fully understand whether the python lambda and the lambda calculus like I read was done by Alonzo Church. I also used it in Javascript, I think. Isn’t this more common in functional languages (e.g. Haskell, Scheme/Lisp, Clojure…) and I never saw lambda in use with Java or C(++)?

Lambda Calculus Free Variable

Here’s something from Slonneger’s “Syntax and Semantics of Programming Languages”:

How to properly diagram lambda expressions or traversals through them in Architecture Explorer?

I’m exploring a piece of code in Architecture Explorer in Visual Studio 2010 to study the relations between methods. I noticed a strange behavior.

What is Java’s primary focus? Why does it take so long to get new features?

I have been exploring the new features in the JDK8, like the lambda expressions, the extension methods, and the new stream API.