Re: character input to functions

[Bill Allombert <Bill.Allombert@math.u-bordeaux1.fr>]

On Thu, Apr 02, 2009 at 12:01:49PM -0500, cino hilliard wrote:
> 
> Exactly what I said. I want to input without having to do the 4 extra keystrokes 
> for quotes for each number. 

Four ?  Two should suffice I think.

> Suppose in the dessert I stumble upon an old and fragial scroll of thousands 
> of numbers in base 32. I have a base(b1,b2,n) that converts n base r1 to r2. 
> I want to determine if the base 32 numbers are prime or not. Now depending, 
> on the starting number, This works. 
> 
> g(n) = isprime(eval(base(32,10,n))). 
> 
> (10:50:38) gp > g(12345ab)
>   ***   too many parameters in user-defined function call: g(12345ab)
>                                                                                          ^---
> 
> So we put n in quotes.
> 
> (10:52:33) gp > g("12345ab")
> %30 = 0
> 
> Yep. That works. I guess I could pay my assistent to simply type in the quotes
> so we would not get the error. Or I could make him think on each number: 

> "To quote or not to quote." This is a terible idea(Sorry Willie). 

OK, so I will give you a tip for free ( so you will save money!):
make your assistant to write all the numbers in a text file 'numbers.txt'
without quotes and one by lines,
then add the quotes with sed -e 's/.*/"&"/'  and read the file under GP
with readvec.

> Because thinking will 
> get errors on input. The input should be rote for maximum accuracy. Then the 
> creative juices abound. Why can't Pari accept all inputs without quotes?  

Because this would conflict with existing syntax:
1e3

? g(n)=n
? g(1e3)
%9 = 1000.0000000000000000000000000000000000
?g(1+1)
%10 = 2

etc.
You do not want 1000.000 to appears in your sequence!

Maybe what you want is:

sread()=extern("read a; echo \\\"$a\\\"")
g(n)=
{
  v=vector(n);
  for(i=1,n,
    s=sread();
    if(s=="",return(vecextract(v,1<<(i-1)-1)));
    v[i]=s);
  v
}

Now do g(100) and start typing your numbers.
Enter an empty line for stopping.

Cheers,
Bill.