my ideas for array operations

[Janice Caron]

On 10/7/07, David Brown <dlang at davidb.org> wrote:
> But, I agree, this doesn't need to be in the language, since it is easy to
> write.

It is worth pondering about efficiency though. Most especially when it
comes to concatenation. That is:

string s = cat(a,b,c,d,e,f,g,h);

ought to be more efficient than

string s = a~b~c~d~e~f~g~h;

because the former could, in principle, require only one allocation,
wheras the latter needs seven.

The fast way:
s.length = a.length + b.length + ...
s[0..a.length] = a[];
s[a.length..a.length+b.length] = b[];
...

Order O(N)

The slow way:
s = a ~ b;
s = s ~ c;
...
s = s ~ h;

Order O(N squared)