www.digitalmars.com         C & C++   DMDScript  

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



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.

-- 
Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
Oct 14 2013
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





 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







 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







 

 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



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.

-- 
Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
Oct 14 2013