Python from Wise Guy's Viewpoint

[Matthew Danish]

On Tue, Oct 28, 2003 at 11:20:45AM +0100, ketil+news at ii.uib.no wrote:
> Matthew Danish <mdanish at andrew.cmu.edu> writes:
> > What is this stuff?  I am talking about integers here!
> 
> But the SML program isn't.  Or it may be, and maybe not.  So it's
> ambigous without type information.
> 
> > Why can't the implementation figure out how to represent them most
> > efficiently? 
> 
> Because it needs a type annotation or inference to decide that the
> numbers are indeed integers, and not a different set with different
> arithmetic properties.

1 is an integer.  Simple type inference.  In Lisp, it's also a fixnum,
it's also an (unsigned-byte 23), it's also an (integer 1 (2)), etc.

> > Lisp gets exact rational arithmetic right, why don't ML or Haskell?
> 
> Could you point to a case where they don't?  I don't understand your 
> criticism at all.  Is the ability to do modulo arithmetic "wrong"?

- fun fact 0 = 1 | fact n = n * fact (n - 1);
val fact = fn : int -> int
- fact 10;
val it = 3628800 : int
- fact 15;
val it = 1307674368000 : int  (* ideally *)

- 1 * 1.0;
val it = 1.0 : float  (* ideally *)

- 2 / 4;
val it = 1/2 : ratio  (* ideally *)

- 2 truncate 4;
val it = 0 : int

-- 
; Matthew Danish <mdanish at andrew.cmu.edu>
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