On Saturday, 26 October 2013 at 23:19:56 UTC, Namespace wrote:
On Saturday, 26 October 2013 at 22:17:33 UTC, Ali Çehreli wrote:
On 10/26/2013 02:25 PM, Namespace wrote:
On Saturday, 26 October 2013 at 21:23:13 UTC, Gautam Goel
wrote:
Dumb Newbie Question: I've searched through the library
reference, but
I haven't figured out how to extract a substring from a
string. I'd
like something like string.substring("Hello", 0, 2) to
return "Hel",
for example. What method am I looking for? Thanks!
Use slices:
string msg = "Hello";
string sub = msg[0 .. 2];
Yes but that works only if the string is known to contain only
ASCII codes. (Otherwise, a string is a collection of UTF-8
code units.)
I could not find a subString() function either but it turns
out to be trivial to implement with Phobos:
import std.range;
import std.algorithm;
auto subRange(R)(R s, size_t beg, size_t end)
{
return s.dropExactly(beg).take(end - beg);
}
unittest
{
assert("abcçdef".subRange(2, 4).equal("cç"));
}
void main()
{}
That function produces a lazy range. To convert it eagerly to
a string:
import std.conv;
string subString(string s, size_t beg, size_t end)
{
return s.subRange(beg, end).text;
}
unittest
{
assert("Hello".subString(0, 2) == "He");
}
Ali
Yeah that is of course easier and nicer than C++... :D Just
kidding. I think the slice should be enough. This example would
have deterred me from further use if I had seen it it in my
beginning.
This functionality should really be provided in phobos str.string!
It is a very common function and I have also made the mistake of
slicing a range in the past :/
