On Sat, Oct 26, 2013 at 6:24 PM, Nicolas Sicard <dran...@gmail.com> wrote:
> On Sunday, 27 October 2013 at 00:18:41 UTC, Timothee Cour wrote:
>
>> I've posted a while back a string=>string substring function that doesn't
>> allocating: google
>> "nonallocating unicode string manipulations"
>>
>> code:
>>
>> auto slice(T)(T a,size_t u, size_t v)if(is(T==string)){//TODO:**generalize
>> to
>> isSomeString
>> import std.exception;
>> auto m=a.length;
>> size_t i;
>> enforce(u<=v);
>> import std.utf;
>> while(u-- && i<m){
>> auto si=stride(a,i);
>> i+=si;
>> v--;
>> }
>> // assert(u==-1);
>> // enforce(u==-1);
>> size_t i2=i;
>> while(v-- && i2<m){
>> auto si=stride(a,i2);
>> i2+=si;
>> }
>> // assert(v==-1);
>> enforce(v==-1);
>> return a[i..i2];
>> }
>> unittest{
>> import std.range;
>> auto a="≈açç√ef";
>> auto b=a.slice(2,6);
>> assert(a.slice(2,6)=="çç√e");
>> assert(a.slice(2,6).ptr==a.**slice(2,3).ptr);
>> assert(a.slice(0,a.walkLength) is a);
>> import std.exception;
>> assertThrown(a.slice(2,8));
>> assertThrown(a.slice(2,1));
>> }
>>
>>
> Another one, with negative index like Javascript's String.slice():
> http://dpaste.dzfl.pl/608435c5
>
not as efficient as what I proposed since it's iterating over the string
twice (the 2nd index redoes the work done by 1st index). Could be adapted
though.
