On Monday, 18 August 2014 at 12:42:25 UTC, monarch_dodra wrote:
On Monday, 18 August 2014 at 11:28:25 UTC, Nordlöw wrote:
On Saturday, 16 August 2014 at 20:59:47 UTC, monarch_dodra
wrote:
I don't get it? If you use "byDchar", you are *explicitly*
decoding. How is that any better? If anything, you are
*preventing* the (many) opportunities phobos has to *avoid*
decoding when it can...
byDchar and alikes are lazy ranges, ie they don't allocate.
Lazy does NOT mean does not allocate. You are making a terrible
mistake if you assume that.
Ok, sorry about that. My mistake. And thanks for correcting me on
this matter.
Furthermore decoding does NOT allocate either. At worst, it can
throw an exception, but that's exceptional.
They also don't throw exceptions which is preferably in some
cases.
Even then, "startsWith(string1, string2)" will *NOT* decode. It
will do a binary comparison of the codeunits. A fast one at
that, since you'll use SIMD vector comparison. Because of this,
it won't throw any exceptions either. This compiles just fine:
void main() nothrow
{
bool b = "foobar".startsWith("foo");
}
Ok, so decoding is needed only when whole and part have different
encodings,
In contrast, with:
whole.byDchar().startsWith(part.byDchar())
You *will* decode. *THAT* will be painfully slow.
Ok.
Read the details at
https://github.com/D-Programming-Language/phobos/pull/2043
If you are using a string, the only thing helpful in there is
`byCodeunit`. The rest is only useful if you have actual ranges.
Actual ranges of...characters and strings? Could you gives some
examples? I'm curious.
If you are using phobos, you should really trust the
implementation that decoding will only happen on a "as needed"
basis.
Ok, got it.
