On Wednesday, March 26, 2014 11:02:04 PM UTC+5:30, Rustom Mody wrote: > On Wednesday, March 26, 2014 9:35:53 PM UTC+5:30, Steven D'Aprano wrote: > > On Wed, 26 Mar 2014 00:30:21 -0400, Terry Reedy wrote: > > > One passes an unquoted expression in code by quoting it with either > > > lambda, paired quote marks (Lisp used a single '),
> > Passing *strings* and *functions* is not the same as having compiler > > support for delayed evaluation. At best its a second-class work-around. > > Contrast: > Once the language has lambda, most else can be fashioned > See the classic papers > lambda the ultimate imperative > lambda the ultimate declarative > lambda the ultimate goto > at here http://library.readscheme.org/page1.html <Details of Jensen implementation snipped> Which I should have summarized as: lambda is the essential Delay operator. So much so that in scheme thaw and freeze are defined as (using pseudo-python syntax) def thaw(x) : return x() freeze(x) is a 'special-form' (aka macro) such that freeze(x) ≡ lambda : x -- https://mail.python.org/mailman/listinfo/python-list
