phobos and splitting things... but not with whitespace.

[Chad J]

On 06/23/2012 01:24 PM, Chad J wrote:
> On 06/23/2012 01:02 PM, simendsjo wrote:
>> On Sat, 23 Jun 2012 18:56:24 +0200, simendsjo <simendsjo at gmail.com>
>> wrote:
>>
>>> On Sat, 23 Jun 2012 18:50:05 +0200, Chad J
>>> <chadjoan at __spam.is.bad__gmail.com> wrote:
>>>
>>>> Looking for findSplit?
>>>> http://dlang.org/phobos/std_algorithm.html#findSplit
>>>> Cool, that's what I want!
>>>> Now if I could find the elegant way to remove exactly one line from
>>>> the text without scanning the text after it...
>>>
>>> Isn't that exactly what findSplit does? It doesn't have to search the
>>> rest of the string after the match, it just returns a slice of the
>>> rest of the array (I guess - haven't read the code)
>>
>>
>> import std.stdio, std.algorithm;
>>
>> void main() {
>> auto text = "1\n2\n3\n4";
>> auto res = text.findSplit("\n");
>>
>> auto pre = res[0];
>> assert(pre.ptr == text.ptr); // no copy for pre match
>>
>> auto match = res[1];
>> assert(match.ptr == &text[1]); // no copy for needle
>>
>> auto post = res[2];
>> assert(post.ptr == &text[2]); // no copy for post match
>> assert(post.length == 5);
>> }
>
> Close... the reason findSplit doesn't work is because a new line could
> be "\n" or it could be "\r\n" or it could be "\r".

As an additional note: I could probably do this easily if I had a 
function like findSplit where the predicate is used /instead/ of a 
delimiter.  So like this:

auto findSplit(alias pred = "a", R)(R haystack);
...
auto tuple = findSplit!(`a == "\n" || a == "\r\n" || a == "\r"`)(text);
return tuple[2];