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digitalmars.D.bugs - [Bug 66] New: Bad length in value of T[a..b] = scalar

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/bugzilla/show_bug.cgi?id=66

           Summary: Bad length in value of T[a..b] = scalar
           Product: D
           Version: 0.150
          Platform: PC
               URL: http://www.digitalmars.com/drn-
                    bin/wwwnews?digitalmars.D.bugs/1725
        OS/Version: Windows
            Status: NEW
          Keywords: wrong-code
          Severity: critical
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla digitalmars.com
        ReportedBy: smjg iname.com


When a slice is assigned by a scalar, the value of the assignment expression
has the length of the whole array, not that of the slice.

----------
import std.stdio;

void show(int[] s) {
    foreach (int i; s) {
        writef("%d ", i);
    }
    writefln();
}

void main() {
    int[] qwert = new int[6];
    int[] yuiop;
    yuiop = qwert[2..5] = 3;
    show(yuiop);
    show(qwert[2..5] = 4);
    show(qwert[2..5]);
    show(qwert);
    show(yuiop[2..5] = qwert[1..4]);

    yuiop = qwert[2..5];
    show(yuiop[1..3] = 6);
    writefln((yuiop[1..3] = 7).length);
}
----------

Output:

3 3 3 0 0 0
4 4 4 0 0 0
4 4 4
0 0 4 4 4 0
0 4 4
6 6 4
3

Expected output:

3 3 3
4 4 4
4 4 4
0 0 4 4 4 0
0 4 4
6 6
2

A testcase (array_chain.d) is also included in my DStress contribution
apparently still waiting to be added (see bug 63).


--
Mar 22 2006
next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/bugzilla/show_bug.cgi?id=66


deewiant gmail.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED





Fixed in 0.151.

Also, unless I'm mistaken, there is a bug in that test code: you have
"show(yuiop[2..5] = qwert[1..4]);" at a point where yuiop's length is 3.
Shouldn't that read "show(yuiop = qwert[1..4]);"? I get your expected output
after that change.


--
Apr 03 2006
prev sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/bugzilla/show_bug.cgi?id=66






You're right that the testcase is buggy.  However, the point was to compare the
behaviour when copying a slice to a slice, whereas your proposed change turns
it into a reference assignment.

A better corretion is simply to add

    yuiop.length = 6;

before that line.


--
Apr 04 2006