http://d.puremagic.com/issues/show_bug.cgi?id=1858

           Summary: std.string find signature is not string
           Product: D
           Version: 2.011
          Platform: All
        OS/Version: Windows
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Phobos
        AssignedTo: bugzilla@digitalmars.com
        ReportedBy: ddparnell@bigpond.com


In std.string, the find and ifind routines use char[] rather than string in their parameter signatures. This seems odd because these functions do not modify the parameter data and most other 'string' functions use string instead of char[]. As most other routines use string I find that I have to make exceptions for these ones in my code.

As a workaround, I need to include the functions below in my code...

int find(string a, string b)
{
    return std.string.find(a.dup, b.dup);
}

int ifind(string a, string b)
{
    return std.string.ifind(a.dup, b.dup);
}

Which involves useless copying.


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http://d.puremagic.com/issues/show_bug.cgi?id=1858





------- Comment #1 from andrei@metalanguage.com  2008-02-21 09:49 -------
The signatures I'm seeing in the current release's codebase (2.0) are all using "in char[]", which is equivalent to "scope const char[]", which accepts mutable, const, and invariant arrays. Could you show a code sample that has a problem? FWIW, this compiles and runs fine on my system:

import std.string;

void main()
{
    string a = "abc", b = "bc";
    assert(find(a, b) == 1);
}


Andrei


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http://d.puremagic.com/issues/show_bug.cgi?id=1858





------- Comment #2 from ddparnell@bigpond.com  2008-02-21 10:09 -------
Here is the type of code that was giving me trouble.

import std.string;
int function(string a, string b) Finder;
void main()
{
    Finder = &std.string.find;
}

I am assuming the compiler is smart enough to work out which 'find' function I'm after by using the signature provided by the 'Finder' declaration.


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http://d.puremagic.com/issues/show_bug.cgi?id=1858





------- Comment #3 from ddparnell@bigpond.com  2008-02-21 10:15 -------
The example code below works just how I expected the compiler to work. It displays '10', so I know it found the right 'xfind' function.


import std.stdio;
int function(string, string) lFind;
void main()
{
    lFind = &xfind;
    writefln("%s", lFind("abc", "def"));
}

int xfind(string x, string y) { return 10; }
int xfind(ubyte[] x, ubyte y) { return 20; }
int xfind(char *x, double y) { return 30; }


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http://d.puremagic.com/issues/show_bug.cgi?id=1858





------- Comment #4 from andrei@metalanguage.com  2008-02-21 12:35 -------
Oh I see. This is best solved in the language - a function type F1 should be implicitly convertible to another function type F2 if all of F1's parameters are subtypes of the corresponding parameters in F2.

Arrays of const are a subtype of arrays of invariant (and actually this is another feature that is needed in a number of places), which takes care of the case in point.

So I hereby assign this to Walter. :o)


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http://d.puremagic.com/issues/show_bug.cgi?id=1858


bugzilla@digitalmars.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement




------- Comment #5 from bugzilla@digitalmars.com  2008-03-02 21:58 -------
Marked as enhancement request.


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http://d.puremagic.com/issues/show_bug.cgi?id=1858


Andrei Alexandrescu <andrei@metalanguage.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
                 CC|                            |andrei@metalanguage.com
         AssignedTo|bugzilla@digitalmars.com    |andrei@metalanguage.com


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Andrei Alexandrescu <andrei@metalanguage.com> changed:

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


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