Functional programming in Python

Dean Herington
Tue, 22 May 2001 13:16:55 -0400 wrote:

>         There's another piece to this question that we're overlooking, I
> think. It's not just a difference (or lack thereof) in precedence, it's the
> fact that parentheses indicate application in Python and many other
> languages, and a function name without parentheses after it is a reference
> to the function, not an application of it. This has nothing to do with
> currying that I can see - you can have curried functions in Python, and they
> still look the same. The main advantage I see for the Haskell style is
> (sometimes) fewer keypresses for parentheses, but I still find it surprising
> at times. Unfortunately in many cases you need to apply nearly as many
> parens for a Haskell expression as you would for a Python one, but they're
> in different places. It's not:
>                 foo( bar( baz( x ) ) )
>         it's:
>                 (foo ( bar (baz x) ) )
>         I'm not sure why folks thought this was an improvement. I suppose it
> bears more resemblance to lambda calculus?

In Haskell, one doesn't need to distinguish "a reference to the function" from
"an application of it".  As a result, parentheses need to serve only a single
function, that of grouping.  Parentheses surround an entire function
application, just as they surround an entire operation application:

        foo (fum 1 2) (3 + 4)

I find this very consistent, simple, and elegant.