[fuzzyman]

Nope - not arbitrary, it is because of the indentation scoping rules. Try coming up with a syntax for statement based lambdas that isn't ugly as heck.

[jashkenas]

First, links for context.

Guido's take: http://www.artima.com/weblogs/viewpost.jsp?thread=147358

Arcieri's take: http://www.unlimitednovelty.com/2009/03/indentation-sensitiv...

It's not hard if we disallow statements, and make everything into an expression that returns a value -- something that Ruby does right. The value of a block of statements is just the value of the last statement in the block.

So, whether you call it a function, or a method, or a lambda, or a block, whitespace with multi-line expressions can be made to work.

The commonly-cited lambda-with-multiple-prints example, in CoffeeScript:

    count: ->
      print 'one'
      print 'two'
      print 'three'