On Friday, 13 June 2014 at 22:12:01 UTC, Ali Çehreli wrote:
On 06/13/2014 03:02 PM, monarch_dodra wrote:
> No, it just receives a range, so it does range formating. eg:
> "[" ~ Element ~ ", " ~ Element ... "]".
It still looks like it could send the formatting characters as
well as the elements separately to the output stream:
"["
Element
", "
...
"]"
I am assuming that the slowness in OP's example is due to
constructing a long string.
Ali
We'd have to check, but don't think that formatted write actually
ever allocates anywhere, so there should be no "constructing a
long string". The real issue (I think), is that when you ask
formatted write to write a string, it just pipes the entire char
array at once to the underlying stream.
If the characters are escaped though (which is the case when you
print an array of strings), then formatedWrite needs to check
each character individually, and then also pass each character
individually to the underlying stream. And *that* could
definitely justify the order of magnitude slowdown observed.
What's more this *may* trigger a per-character decode-encode
loop. I'd have to check. But that shouldn't be observable next to
the stream overhead anyways.
