On Wednesday, 20 April 2016 at 22:44:37 UTC, ag0aep6g wrote:
On 20.04.2016 23:59, Alex Parrill wrote:
On Wednesday, 20 April 2016 at 17:09:29 UTC, Matt Kline wrote:
[...]
First, you can't assign anything to a void[], for the same
reason you
can't dereference a void*. This includes the slice assignment
that you
are trying to do in `buf[0..minLen] =
remainingData[0..minLen];`.
Not true. You can assign any dynamic array to a void[].
That's not assigning the elements of a void[]; it's just changing
what the slice points to and adjusting the length, like doing
`void* ptr = someOtherPtr;`
Regarding vector notation, the spec doesn't seem to mention how
it interacts with void[], but dmd accepts this no problem:
----
int[] i = [1, 2, 3];
auto v = new void[](3 * int.sizeof);
v[] = i[];
----
It only seems to work on arrays, not arbitrary ranges, sliceable
or not. Though see below.
[...]
Second, don't use slicing on ranges (unless you need it). Not
all ranges
support it...
As far as I see, the slicing code is guarded by `static if
(isArray!T)`. Arrays support slicing.
[...]
Instead, use a loop (or maybe `put`) to fill the array.
That's what done in the `else` path, no?
Yes, I did not see the static if condition, my bad.
Third, don't treat text as bytes; encode your characters.
auto schema = EncodingScheme.create("utf-8");
auto range = chain("hello", " ", "world").map!(ch =>
cast(char) ch);
auto buf = new ubyte[](100);
auto currentPos = buf;
while(!range.empty && schema.encodedLength(range.front) <=
currentPos.length) {
auto written = schema.encode(range.front, currentPos);
currentPos = currentPos[written..$];
range.popFront();
}
buf = buf[0..buf.length - currentPos.length];
You're "converting" chars to UTF-8 here, right? That's a nop.
char is a UTF-8 code unit already.
It can be either chars, wchars, or dchars.
(PS there ought to be a range in Phobos that encodes each
character,
something like map maybe)
std.utf.byChar and friends:
https://dlang.org/phobos/std_utf.html#.byChar
byChar would work. byWChar and byDChar might cause endian-ness
issues.
