Re: eval of numeric strings

[Bill Allombert <Bill.Allombert@math.u-bordeaux.fr>]

On Thu, Oct 22, 2015 at 02:39:08PM +0200, Josef Eschgfaeller wrote:
> I would like to define a function evaln
> which evaluates a string to a number
> only if the string contains explicitly
> the decimal representation of that
> number, not a variable.
> --------------------------------------------------
> Behavior of eval:
> 
> x=17;
> s=eval("x"); print(s); \\ 17.
> t=eval("17"); print(t); \\ 17.
> y="John"
> r=eval("y"); print(r); \\ John
> --------------------------------------------------
> Desired behavior of evaln:
> 
> x=17;
> s=evaln("x"); print(s); \\ x.
> t=evaln("17"); print(t); \\ 17.
> y="John"
> r=evaln("y"); print(r); \\ y.

What should give:
evaln("x2")
evaln("2x")

Cheers,
Bill.