Re: Function to print a diamond shape

[Jay Norwood via Digitalmars-d-learn]

Wow,  joiner is much slower than join.  Such a small choice can 
make this big of a difference.  Not at all expected, since the 
lazy calls, I thought, were considered to be more efficient.  
This is with ldc2 -O2.

jay@jay-ubuntu:~/ec_ddt/workspace/diamond/source$ ./main 
1>/dev/null
brad: time: 21958[ms]
sergei: time: 24629[ms]
jay2: time: 259[ms]
diamondShape: time: 6701[ms]
printDiamond: time: 194[ms]
printDiamonde2a: time: 95[ms]
printDiamonde2b: time: 92[ms]
printDiamond3: time: 144[ms]
printDiamonde2monarch: time: 67[ms]
printDiamonde2cJoin: time: 96[ms]
printDiamonde2cJoiner: time: 16115[ms]

void printDiamonde2cJoin(in uint N)
{
        int n,l;
    size_t N2 = N/2;
    size_t NM1 = N-1;
    char p[] = uninitializedArray!(char[])(N2+N);
    p[0..N2] = ' ';
    p[N2..$] = '*';
    char nl[] = uninitializedArray!(char[])(1);
    nl[] = '\n';

    char wc[][] = minimallyInitializedArray!(char[][])(N);

    for(n=0,l=0; n<N2; n++,l+=2){
        wc[n] = wc[NM1-n] = p[n .. N2+l+1];
    }

    wc[N2] = p[N2..$];
    auto wj = join(wc,nl);
    write(wj);
    write('\n');
}

void printDiamonde2cJoiner(in uint N)
{
        int n,l;
    size_t N2 = N/2;
    size_t NM1 = N-1;
    char p[] = uninitializedArray!(char[])(N2+N);
    p[0..N2] = ' ';
    p[N2..$] = '*';

    char wc[][] = minimallyInitializedArray!(char[][])(N);

    for(n=0,l=0; n<N2; n++,l+=2){
        wc[n] = wc[NM1-n] = p[n .. N2+l+1];
    }

    wc[N2] = p[N2..$];
    write(joiner(wc,"\n"));
    write('\n');
}