On Friday, 24 April 2015 at 11:33:48 UTC, John Colvin wrote:
On Friday, 24 April 2015 at 10:22:05 UTC, Chris wrote:
I replaced a range that was similar to map with map and the
performance dropped by ~0.5 msec.
The range I used previously is based on Adam's D Cookbook. It
is consistently faster than map.
private struct Transformer(alias agent, R) if (isInputRange!R)
{
private R r;
this (R r) {
this.r = r;
}
static if (isInfinite!R) {
enum bool empty = false;
}
else {
@property bool empty() {
return r.empty;
}
}
void popFront() {
r.popFront();
}
@property ref auto front() {
return agent(r.front);
}
static if (isForwardRange!R) {
@property auto save() {
return Transformer!(agent, R)(r.save);
}
}
static if (isBidirectionalRange!R) {
@property auto back() {
return agent(r.back);
}
void popBack() {
r.popBack();
}
}
static if (isRandomAccessRange!R) {
auto opIndex(size_t i) {
return agent(r[i]);
}
}
static if (hasLength!R) {
@property auto length() {
return r.length;
}
}
}
That is pretty much identical to the implementation of map, see
https://github.com/D-Programming-Language/phobos/blob/master/std/algorithm/iteration.d#L504
Yeah, I saw that.
The only difference is that you don't implement opSlice.
Perhaps slicing is particularly slow for your source range?
The source range is a string[][].
