[racket] TR Numeric Tower

From: Matthias Felleisen (matthias at ccs.neu.edu)
Date: Wed Feb 13 22:15:14 EST 2013

That's just semantics, you dang logician 


On Feb 13, 2013, at 10:09 PM, Carl Eastlund wrote:

> That might not be what he wants either, if he wants anything representable as a flonum to be a flonum.  For instance, (S->F "5") is #false by your implementation.  It's hard to tell exactly what S->F is supposed to do without more of a specification.
> 
> Carl Eastlund
> 
> 
> On Wed, Feb 13, 2013 at 10:04 PM, Matthias Felleisen <matthias at ccs.neu.edu> wrote:
> 
> #lang typed/racket
> 
> (: S->F : String -> (Option Float))
> (define (S->F s)
>   (define n (string->number s))
>   (and (flonum? n) n))
> 
> I assume you mean to convert strings into floats, if possible.
> 
> But you may like the funny answers better -- Matthias
> 
> 
> 
> On Feb 13, 2013, at 9:49 PM, Ray Racine wrote:
> 
> > What is the most efficient way to write the following method in TR?
> >
> > (: S->F (String -> (Option Float)))
> >
> >
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