Late-binding of function defaults (was Re: What is a function parameter =[] for?)

[BartC]

On 26/11/2015 00:31, Steven D'Aprano wrote:
> On Thu, 26 Nov 2015 09:41 am, BartC wrote:
>
>> Maybe you're too familiar with it. But the idea of executing the
>> function and other definitions in a file, instead of they just being
>> there, is novel.
>
>
> It really, truly isn't. Your viewpoint is clouded by too much immersion in
> crippled languages. *Old and obsolete versions* of crippled languages.
> Dynamic creation of functions goes back to the 1950s.
>
> Functions in Python are *first class values*, just like ints, strings, lists
> etc. That means functions can be passed around as arguments, assigned to
> variables, returned from functions, and created on the fly as needed. This
> is not an innovation from Python -- Python rarely, if ever, innovates. By
> the time any feature hits Python (yes, even significant indentation) it has
> typically been proven in at least one other language.
>
> Languages with first class functions include Perl, Javascript, Lua, PHP,
> Tcl/Tk, Io, Go, Rust, Maple, Mathematica, Smalltalk, Swift, and varied mix
> of old (Smalltalk and Perl) and new (Rust and Swift).
>
> It is almost unthinkable to imagine a functional programming language
> without this feature, and sure enough Scala, Haskell, ML, Clojure, and
> Scheme have it -- as does Lisp, which is the second oldest high level
> language in existence. Only Fortran is older.
>
> Delphi (a variant on Pascal/Algol) has supported them since 2009. C++, C#
> and Objective C have support for first class functions. Even Java 8 and
> above includes this feature.
>
> In 2015, it's hard to think of any non-obsolete, non-toy language which
> doesn't treat functions as first-class values, including creating them on
> the fly. Fortran and C perhaps.

It's funny then that the vast majority of top-level function definitions 
I see in Python (and import and class statements too) are decidedly static.

The names are declared, but the names are rarely bound to anything else. 
Functions are just called the same boring way they are in C.

/They might as well be static definitions/.

(In fact, all this dynamic set-up, while it makes for an elegant and 
consistent language, probably also makes it unnecessarily harder to 
accelerate.)

Clearly a huge amount of programming can be done without having to deal 
with first-class functions (or constructing functions at run-time; that 
sounds fun). (Or without using OOP, another thing I can't stand.)

Some people just don't want to be functional programmers. It is elitist 
to try and make out it that it is that important.

If lots of languages now have functional features, it's more likely to 
be a case of keeping up with the Joneses.

-- 
Bartc