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Which popular language nowadays doesn't have closures? Even the so hated (by HN) PHP has had that for many years already.

• tomjen3 12y ago
  Python is often claimed not to have closures but that isn't really true, what it doesn't have is anonymous functions. It does have a lambda statement, but that is limited to a single statement. So what you end up writing is more akin to: def multiplier_maker(a): def temp(b): return b * a return temp That is because Python allows you to declare a function anyware, even inside other functions.
  • sebleblanc 12y ago
    And if you want to emulate static variables in a function, you can do that: def counter(): counter.x += 1 return counter.x counter.x = 0 counter() > 1 counter() > 2 Beware! singleton variables, mutable state, etc.
    • knome 12y ago
      You can do it by closing over a variable as well. Python closes over things just fine, it just has problems rebinding variables in outer scopes that aren't the global one. Here, I just make the variable a container, so I can alter a value inside it, instead of rebinding it ( only python2 has this problem, python3 has a "nonlocal" keyword to work around this in the language ) >>> def counter(): ... x = [ 1 ] ... def count(): ... y = x[ 0 ] ... x[ 0 ] += 1 ... return y ... return count ... >>> count = counter() >>> count() 1 >>> count() 2 >>> count() 3 >>> count() 4 >>> >>> otherCount = counter() >>> otherCount() 1 >>> otherCount() 2 >>> count() 5 >>> count() 6 >>> otherCount() 3 >>>
  • jafaku 12y ago
    > what it doesn't have is anonymous functions If it's not anonymous it's not a closure though.
    • tomjen3 12y ago
      Bullshit. It closures around its environment, it is a closure.
• nemothekid 12y ago
  Python.
  • knome 12y ago
    Under what definition of closure does python lack them?