The only way I can see is via a log transform, and that seems clumsy.

    ----

Alternative question:  How does one return the hash value of a string?  data.toHash doesn't work, and neither does string.getHash(data).  I suspect one working answer will turn out to be something like:
  cast(Object [])data.toHash

(I haven't yet tried that variation), but it seems like it should have a simpler answer.  So what's the *proper* way to do it?

Charles Hixson schrieb:

> The only way I can see is via a log transform, and that seems clumsy.

D doesn't seem to have an operator for it, and it's not in the math library. (Or: I'm really dumb and overlooked it in the docs.)

Maybe you can work with this:



version (standalone) {
  import conv;
  import string;
  import stream;
}

bool isOdd(uint i) {
  return (i & 1) == 1;
}

uint exp(uint b, uint e) {
  if (e == 0) return 1;
  int r = 1;
  int y = b;
  while (e > 1) {
    if (isOdd(e)) r *= y;
    e = e >> 1;
    y *= y;
  }
  r *= y;
  return r;
}

version (standalone) {
  int main(char[][] args) {
    stream.stdout.writeLine(toString(exp(toUint(args[1]),toUint(args[2]))));
    return 0;
  }
}

"Charles Hixson" <charleshixsn@earthlink.net> wrote in message news:blib9f$ke2$1@digitaldaemon.com...
> Alternative question:  How does one return the hash value of a string?

This seems to be the only standard way:

import stream;
uint dataHash = (new MemoryStream(cast(ubyte[])data)).toHash()

Note: if data is a string literal and you don't want to use wchar's, cast it to char[] first.

Vathix wrote:
> "Charles Hixson" <charleshixsn@earthlink.net> wrote in message
> news:blib9f$ke2$1@digitaldaemon.com...
> 
>>Alternative question:  How does one return the hash value of a
>>string?
> 
> 
> This seems to be the only standard way:
> 
> import stream;
> uint dataHash = (new MemoryStream(cast(ubyte[])data)).toHash()
> 
> Note: if data is a string literal and you don't want to use wchar's, cast it
> to char[] first.
> 
> 
> 
Thanks.  Considering the periginations I would appearantly have to go through to use exponentiation, that saves a bunch of trouble.

Charles Hixson wrote:
> 
> The only way I can see is via a log transform, and that seems clumsy.
> 

Perhaps something like:

  import math;

  double x,y,z;

  z=pow(x,y);

(untested)


-- 
Helmut Leitner    leitner@hls.via.at
Graz, Austria   www.hls-software.com

Charles Hixson wrote:
> 
> The only way I can see is via a log transform, and that seems clumsy.
extern (C) double pow(double b, double e);

then link with -lm.

-- 
+----------------------------------------------------------------------+ I Dr. Olaf Rogalsky                         Institut f. Theo. Physik I I I Tel.: 09131 8528440                       Univ. Erlangen-Nuernberg   I I Fax.: 09131 8528444                       Staudtstrasse 7 B3         I I rogalsky@theorie1.physik.uni-erlangen.de  D-91058 Erlangen           I +----------------------------------------------------------------------+

Ideally we wouldn't have to depend on the C runtime library at all.

Sean

"Olaf Rogalsky" <olaf.rogalsky@theorie1.physik.uni-erlangen.de> wrote in message news:3F81544F.A2386DA9@theorie1.physik.uni-erlangen.de...
> extern (C) double pow(double b, double e);

"Sean L. Palmer" wrote:
> 
> Ideally we wouldn't have to depend on the C runtime library at all.
Agreed! Personally I would like to see an internal '**' power operator, overloaded for the basic numeric types.

Why internal? `cause then the compiler could optimize constant expressions.

Why a new '**' operator? Why not. It's concise, and eyecatching. The greatest disadvantage in the lisp family of languages is not having too many parentheses (for experienced programmers they become opaque), but the uniform syntax. Machines are good at parsing a language with uniform syntax, humans are not!

Olaf
-- 
+----------------------------------------------------------------------+ I Dr. Olaf Rogalsky                         Institut f. Theo. Physik I I I Tel.: 09131 8528440                       Univ. Erlangen-Nuernberg   I I Fax.: 09131 8528444                       Staudtstrasse 7 B3         I I rogalsky@theorie1.physik.uni-erlangen.de  D-91058 Erlangen           I +----------------------------------------------------------------------+