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digitalmars.D.bugs - [Issue 10176] New: std.array.extend?

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=10176

           Summary: std.array.extend?
           Product: D
           Version: D2
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: enhancement
          Priority: P2
         Component: Phobos
        AssignedTo: nobody puremagic.com
        ReportedBy: bearophile_hugs eml.cc



Maybe it's worth adding a std.array.extend() function that's similar to "~="
but accepts a lazy range (in theory, in a language where ranges are built-ins,
~= should append ranges too to arrays).

In std.array there is a join, but it creates a whole new array. It's usually
more efficient to extend arrays.


foreach (x; myrange)
    myarray ~= x;


Is replaced by:

myarray.extend(myrange);

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next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=10176


Andrej Mitrovic <andrej.mitrovich gmail.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |andrej.mitrovich gmail.com



06:21:09 PDT ---
Hmm, I would have hoped that 'put' would work here, but it doesn't:

-----
import std.range;
import std.array;

void main()
{
    {
        Appender!(int[]) arr;
        arr.put(iota(5));  // ok
        assert(arr.data == [0, 1, 2, 3, 4]);
    }

    {
        int[] arr;
        arr.put(iota(5));  // runtime exception
        assert(arr == [0, 1, 2, 3, 4]);
    }
}
-----


 core.exception.AssertError C:\dmd-git\dmd2\windows\bin\..\..\src\phob
s\std\array.d(587): Attempting to fetch the front of an empty array of int


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prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=10176


bearophile_hugs eml.cc changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|std.array.extend?           |Something to extend an
                   |                            |array with a lazy range



More general issue summary.

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prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=10176


Jonathan M Davis <jmdavisProg gmx.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jmdavisProg gmx.com



PDT ---

 Hmm, I would have hoped that 'put' would work here, but it doesn't:


put on arrays does not append. It starts writing at the beginning of the array.
So, it functions fundamentally differently from most output ranges. Presumably,
it's the desired behavior if you're dealing with a pre-allocated chunk of
memory that you're trying to fill, but it is problematic in that it doesn't
function like other output ranges. I've been think of opening a discussion in
the newsgroup on it so that we can figure out how to better sort out some of
these quirks of output ranges.

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prev sibling parent d-bugmail puremagic.com writes:
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02:06:50 PDT ---


 Hmm, I would have hoped that 'put' would work here, but it doesn't:


 
 put on arrays does not append. It starts writing at the beginning of the array.


That makes sense now that I think about it.

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