[Ironruby-core] Comparing CLR strings and Ruby strings - a slightly surprising behaviour

Meinrad Recheis meinrad.recheis at gmail.com
Tue Mar 3 17:19:07 EST 2009

On Tue, Mar 3, 2009 at 11:11 PM, Meinrad Recheis
<meinrad.recheis at gmail.com>wrote:

> On Tue, Mar 3, 2009 at 9:46 PM, Thibaut Barrère <thibaut.barrere at gmail.com
> > wrote:
>> Hi,
>> while writing specs for Magic, I noticed that:
>> instance_from(MenuItem, "Hello").text.*to_s*.should == "Hello"
>> to_s is required to get the assertion to pass. The following will return
>> false:
>> button = Button.new
>> button.text = "Hello"
>> puts button.text == "Hello"
>> So I guess that CLR strings cannot be compared to Ruby strings unless to_s
>> is applied.
> I have stumbled on this too and was very surprised. This problem does not
> exist in IronPython (does it? please correct me if I am wrong). The behavior
> I was expecting is that "on the ruby" side all strings are (or at least
> behave exactly like) ruby strings, even if they come from .NET and are
> automatically converted to clr-strings when passed into clr methods.

In addition to that, it would also be great to have automatic type
conversion on the .NET side too. I'd expect to be able to assign a string
pulled out from the interpreter to a C# string without the need to call
ToString(). For example,

string s = engine.Execute("'hi'") as string;

Currently s would be null because the dynamic cast to System.String fails.
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