chris blogs: Dynamic Variables in Ruby

chris blogs: Dynamic Variables in Ruby:

« Blindschleichen, Pazifische und Gürkinen April 2005 Papa Razi und Soldaten » 24apr2005 · Dynamic Variables in Ruby Many Lisps provide dynamically scoped or special variables additionally to lexically scoped ones. Some (for example Elisp or ye olde MacLisp) even soley provide dynamically scoped variables. In fact, Scheme was the first lisp-based language to make lexical scoping popular. Now, what’s the difference between dynamic and lexical scoping? Lexical scoping should be known to every Rubyist, as this is the usual (and the only one provided by default) way of scoping. Lexical scoping has the major advantage of enabling closures, that is, pieces of code that save their lexical environment. For example, in Ruby you can write: def adder(n) v = 0 # v is lexically scoped here lambda { v += n } # v and n are accessed from the closure end add1 = adder(10) p add1.call #=> 10...

Full article: http://chneukirchen.org/blog/archive/2005/04/dynamic-vari...