Functional programming in Python

[S. Alexander Jacobson]

Does anyone know why the haskell designers did not make the syntax
right associative?  It would clean up a lot of stuff.

Haskell					Non-Haskell
Left Associative			Right Associative
foo (bar (baz (x)))			foo bar baz x
foo $ bar $ baz x			foo bar baz x
add (square x) (square y) 		add square x square y
add (square x) y	 		add square x y
------------From Prelude----------------------
map f x					(map f) x
f x (n - 1) x				f x n - 1 x
f x (foldr1 f xs)			f x foldr1 f xs
showChar '[' . shows x . showl xs	showChar '[] shows x showl xs

You just need to read from right to left accumulating a stack of
arguments.  When you hit a function that can consume some arguments, it
does so.  There is an error if you end up with more than one value on
the argument stack.

-Alex-



On Fri, 25 May 2001, Tom Pledger wrote:

> Peter Douglass writes:
>  :
>  | but in ( foo ( bar (baz x) ) )
>  |
>  | You would want the following I think.
>  |
>  |      foo . bar . baz x
>  |
>  | which does have the parens omitted, but requires the composition
>  | operator.
>
> Almost.  To preserve the meaning, the composition syntax would need to
> be
>
>     (foo . bar . baz) x
>
> or
>
>     foo . bar . baz $ x
>
> or something along those lines.  I favour the one with parens around
> the dotty part, and tend to use $ only when a closing paren is
> threatening to disappear over the horizon.
>
>     do ...
>        return $ case ... of
>            ... -- many lines
>
> Regards,
> Tom
>
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