[Ironruby-core] WinForms event handling

Andrew S. Townley ast at atownley.org
Wed Apr 22 05:26:17 EDT 2009


Hi Jimmy,

> In the latest builds this will work:
> 
> >>> s = System::String.new 'fubar'
> => 'fubar'
> >>> s.class
> => System::String
> 
> Note that the result is single-quoted; that's a little hint that it's a System::String rather than a Ruby String. The reason they are different is mutability; Ruby strings are mutable, while the CLR's are not. Unfortunately this means that not all the methods on a Ruby string can work on a CLR string (like sub!, slice!, etc), but we have added any non-mutable methods to CLR strings:
> 
> >>> s.upcase
> => "FUBAR"
> 
> And any mutable methods will throw:
> 
> >>> s.upcase!
> :0: Mutating method `upcase!' called for an immutable string (System::String) (TypeError)

I'd forgotten that CLR strings were immutable.  It's been a while since I was doing anything on the CLR.

Cheers for the feedback.

ast

> > -----Original Message-----
> > From: ironruby-core-bounces at rubyforge.org [mailto:ironruby-core-
> > bounces at rubyforge.org] On Behalf Of Andrew S. Townley
> > Sent: Tuesday, April 21, 2009 10:08 AM
> > To: ironruby-core at rubyforge.org
> > Subject: [Ironruby-core] WinForms event handling
> >
> > Hi,
> >
> > I was doing a bit of experimenting with ironruby today to see if it
> > might be useful for some prototyping work that I'm doing.  I noticed
> > that any of the strings returned from the CLR don't automatically
> > include the ruby string methods.  I would've expected that these would
> > be mapped directly so that you could call @textfield.text.strip instead
> > of @textfield.text.trim.
> >
> > Probably low on the priority list, but was just curious what the plan
> > was.  Assignment to locally created string references doesn't help
> > either.  I know it's early days yet, but this sort of thing will make
> > it
> > difficult for people to remember which API applies where--especially if
> > CLR strings "escape" a particular method context.
> >
> > Interesting things seem to also happen if you try and create a CLR type
> > directly:
> >
> > C:\>ir -v
> > IronRuby 0.3 0.3.0.0 on .NET 2.0.0.0
> >
> > C:\>iirb
> > irb(main):001:0> require 'mscorlib'
> > => true
> > irb(main):002:0> s = System::String.new "fubar"
> > TypeError: can't convert String into System::Char*
> >         from (irb):0
> >         from :0:in `eval'
> >         from workspace.rb:80:in `evaluate'
> >         from context.rb:217:in `evaluate'
> >         from irb.rb:147:in `eval_input'
> >         from irb.rb:253:in `signal_status'
> >         from irb.rb:146:in `eval_input'
> >         from ruby-lex.rb:230:in `each_top_level_statement'
> >         from :0:in `loop'
> >         from ruby-lex.rb:229:in `each_top_level_statement'
> >         from :0:in `catch'
> >         from ruby-lex.rb:227:in `each_top_level_statement'
> >         from irb.rb:102:in `eval_input'
> >         from irb.rb:69:in `start'
> >         from :0:in `catch'
> >         from irb.rb:51:in `start'
> >         from iirb:0irb(main):003:0>
> >
> > The only way that I've found to ensure that it's really a Ruby string
> > is
> > to do something like this
> >
> > s = "" << clrstring
> >
> > Has anyone else hit this yet?
> >
> > Cheers,
> >
> > ast
> > --
> > Andrew S. Townley <ast at atownley.org>
> > http://atownley.org
> >
> > _______________________________________________
> > Ironruby-core mailing list
> > Ironruby-core at rubyforge.org
> > http://rubyforge.org/mailman/listinfo/ironruby-core
> 
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--
Andrew S. Townley <ast at atownley.org>
http://atownley.org



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