Re: D looses in speed to Common Lisp

[Justin Whear via Digitalmars-d]

All those allocations aren't helping.  Here's a much more idiomatic D 
version:

import std.stdio, std.bigint;
import std.range;
void main() {
        int n = 100000;
        auto fib1 = recurrence!("a[n-1] + a[n-2]")(BigInt(0), BigInt
(1)).takeExactly(n);
        auto fib2 = recurrence!("a[n-1] + a[n-2]")(BigInt(0), BigInt
(1)).takeExactly(n);

        BigInt sumFib1;
        foreach (e; fib1)
                sumFib1 += e;

        BigInt sumFib2;
        foreach (e; fib2)
                sumFib2 += e;

        writeln(sumFib2 - sumFib1); // 0
}

Timing on my box:
$ time ./fib
0

real    0m1.520s
user    0m1.520s
sys     0m0.000s

Compiling with `ldmd2 fib.d -inline -noboundscheck -O -release`:
$ time ./fib
0

real    0m0.784s
user    0m0.776s
sys     0m0.000s