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digitalmars.D.bugs - [Issue 11254] New: std.string.strip is not nothrow

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=11254

           Summary: std.string.strip is not nothrow
           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


--- Comment #0 from bearophile_hugs eml.cc 2013-10-14 02:52:27 PDT ---
import std.string: strip;
void main() nothrow {
    " hello ".strip;
}



dmd 2.064beta gives:

test.d(3): Error: 'std.string.strip!(immutable(char)).strip' is not nothrow
test.d(2): Error: function 'D main' is nothrow yet may throw


I don't know if this can be done. Often string functions need to decode UTF,
and this could raise exceptions. In most cases, or for ASCII strings, a strip
can't throw exceptions.

If this can't be done then please close down this issue.

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next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=11254


monarchdodra gmail.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |monarchdodra gmail.com
         Resolution|                            |INVALID


--- Comment #1 from monarchdodra gmail.com 2013-10-14 05:55:11 PDT ---
(In reply to comment #0)
 import std.string: strip;
 void main() nothrow {
     " hello ".strip;
 }
 
 
 
 dmd 2.064beta gives:
 
 test.d(3): Error: 'std.string.strip!(immutable(char)).strip' is not nothrow
 test.d(2): Error: function 'D main' is nothrow yet may throw
 
 
 I don't know if this can be done. Often string functions need to decode UTF,
 and this could raise exceptions. In most cases, or for ASCII strings, a strip
 can't throw exceptions.
 
 If this can't be done then please close down this issue.
strip is a unicode aware function, that can remove unicode whites, so it *must* decode. So even if "most of the time", it won't throw, in the generic case, it can. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Oct 14 2013
prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=11254



--- Comment #2 from bearophile_hugs eml.cc 2013-10-14 09:46:51 PDT ---
(In reply to comment #1)

 strip is a unicode aware function, that can remove unicode whites, so it *must*
 decode. So even if "most of the time", it won't throw, in the generic case, it
 can.
Some possible alternative solutions: - A strip-like function that works on ubyte[] (the return type of std.string.representation if you give it a string); - A compile-time switch for std.string.strip that compiles out the unicode-aware parts. - A std.ascii.astrip nothrow function designed to work only on ASCII strings/char[]. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Oct 14 2013
prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=11254



--- Comment #3 from monarchdodra gmail.com 2013-10-14 11:50:50 PDT ---
(In reply to comment #2)
 (In reply to comment #1)
 
 strip is a unicode aware function, that can remove unicode whites, so it *must*
 decode. So even if "most of the time", it won't throw, in the generic case, it
 can.
Some possible alternative solutions: - A strip-like function that works on ubyte[] (the return type of std.string.representation if you give it a string); - A compile-time switch for std.string.strip that compiles out the unicode-aware parts. - A std.ascii.astrip nothrow function designed to work only on ASCII strings/char[].
You should try the new generic std.algorithm.strip: //---- import std.string, std.ascii, std.algorithm; void main(string[] args) nothrow pure { string s = " hello! "; s = cast(string)s.representation.strip!isWhite(); } //---- -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Oct 14 2013
prev sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=11254


Jonathan M Davis <jmdavisProg gmx.com> changed:

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


--- Comment #4 from Jonathan M Davis <jmdavisProg gmx.com> 2013-10-14 19:41:32
PDT ---
I think that we should probably move towards overloading string functions with
ubyte[] so that they can have ASCII-specific versions, and more of those would
be able to be nothrow.

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