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digitalmars.D.bugs - [Issue 4165] New: std.conv.to!int doesn't ignore whitespace

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=4165

           Summary: std.conv.to!int doesn't ignore whitespace
           Product: D
           Version: future
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Phobos
        AssignedTo: nobody puremagic.com
        ReportedBy: bearophile_hugs eml.cc


--- Comment #0 from bearophile_hugs eml.cc 2010-05-09 05:20:45 PDT ---
Too much flexibility in a language and its libs causes several problems, but
the opposite too makes the language and its use fussy. So there is a right
intermediate point of balance to be found.

The conversion from string to numbers performed by std.conv.to is excessively
rigid.

In Python this conversion works:

 int(" 0123\n")
123 In D v.2.043 the same produces an error: import std.conv: to; void main() { int x = to!int(" 0123\n"); } std.conv.ConvError: Can't convert value ` 0123 ' of type const(char)[] to type int Can std.conv.to be modified to ignore whitespace? In particular the ending newline is very common, for example every time I want to convert a line from a text file to a number I have to use something like this: to!int(readln().chomp()); Instead of a simpler: to!int(readln()); -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
May 09 2010
next sibling parent d-bugmail puremagic.com writes:
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--- Comment #1 from bearophile_hugs eml.cc 2010-05-22 14:24:20 PDT ---
A comment by Adam Ruppe:
 I don't think that's a bug. It should only worry about converting, not
 filtering out bad stuff. That's an orthogonal problem that the other
 function does well, and easily too.
It's not a bug. But saying it's an orthogonal problem is not enough. You must keep a balance between having a so flexible language/stdlib that's sloppy and can lead to bugs, and to have as much orthogonal functions as possible that are fussy and can lead to opposite kinds of bugs. Often if I have to convert strings to numbers that have a leading newline. Converting such string with leading newline to a number is not sloppiness because my experience shows me it doesn't cause bugs in Python. The way to!() is currently designed forces me to remove the spaces often. This has caused a bug in one script-like D program. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
May 22 2010
prev sibling next sibling parent d-bugmail puremagic.com writes:
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Lars T. Kyllingstad <bugzilla kyllingen.net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bugzilla kyllingen.net
           Severity|normal                      |enhancement


--- Comment #2 from Lars T. Kyllingstad <bugzilla kyllingen.net> 2010-08-13
03:27:02 PDT ---
Since we all agree this is not a bug, I'm marking it as an enhancement request.

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Aug 13 2010
prev sibling parent d-bugmail puremagic.com writes:
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David Simcha <dsimcha yahoo.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |dsimcha yahoo.com
         Resolution|                            |WONTFIX


--- Comment #3 from David Simcha <dsimcha yahoo.com> 2010-08-15 08:10:52 PDT ---
I'm marking this as wontfix because it's by design (it's mentioned in the docs
of std.conv), and there's a trivial workaround:

int x = to!int(" 0123\n".strip());

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Aug 15 2010