On 10/11/17 7:06 PM, Johan Engelen wrote:
On Wednesday, 11 October 2017 at 22:45:14 UTC, Jonathan M Davis wrote:
On Wednesday, October 11, 2017 22:22:43 Johan Engelen via
Digitalmars-d- learn wrote:
std.string.removechars is now deprecated.
https://dlang.org/changelog/2.075.0.html#pattern-deprecate
What is now the most efficient way to remove characters from a
string, if only one type of character needs to be removed?
```
// old
auto old(string s) {
return s.removechars(",").to!int;
}
// new?
auto newnew(string s) {
return s.filter!(a => a != ',').to!int;
}
```
Well, in general, I'd guess that the fastest way to remove all
instances of a character from a string would be std.array.replace with
the replacement being the empty string,
Is that optimized for empty replacement?
but if you're feeding it to std.conv.to rather than really using the
resultant string, then filter probably is faster, because it won't
allocate. Really though, you'd have to test for your use case and see
how fast a given solution is.
Performance-wise, I would use neither, as both autodecode (removechars
by using the opaque/slow foreach decoding) and reencode.
Especially if you are removing a single ascii char.
I am disappointed to see functions being deprecated, without an
extensive documentation of how to rewrite them for different usage of
the deprecated function. It makes me feel that no deep thought went into
removing them (perhaps there was, I can't tell).
One has to go and browse through the different version _release notes_
to find any documentation on how to rewrite them. It would have been
much better to add it (aswell) to the deprecated function documentation.
This should have been done. A deprecation in this manner where there is
no exact path forward is confusing and unnecessary. If we are
deprecating a function, the person deprecating the function should have
had a replacement in mind. The only way the message could be worse is if
it said "please use other functions in Phobos".
-Steve
