# MutableString vs string

**URL:** <https://www.ruby-forum.com/t/mutablestring-vs-string/122359>\
**Category:** IronRuby\
**Created:** [December 6, 2007, 10:56pm UTC](https://www.ruby-forum.com/t/mutablestring-vs-string/122359 "2007-12-06T22:56:52Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![editkid](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/977dab/32.png) [@editkid](https://www.ruby-forum.com/u/editkid)\
**Post date:** [December 6, 2007, 10:56pm UTC](https://www.ruby-forum.com/t/mutablestring-vs-string/122359/1 "2007-12-06T22:56:52Z")

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Along the lines of the discussion before about raising exceptions: Is it  
acceptable to return .NET strings from library methods or should we be  
trying to use MutableString instances?

Pete

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**Author:** ![editkid](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/977dab/32.png) [@editkid](https://www.ruby-forum.com/u/editkid)\
**Post date:** [December 6, 2007, 11:22pm UTC](https://www.ruby-forum.com/t/mutablestring-vs-string/122359/2 "2007-12-06T23:22:06Z")

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Good question… I’m using always MutableString inside my StringIO  
implementation but I’m not sure if it’s ok…

On Dec 6, 2007 3:54 PM, Peter Bacon D. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)

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**Author:** ![editkid](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/977dab/32.png) [@editkid](https://www.ruby-forum.com/u/editkid)\
**Post date:** [December 7, 2007, 12:02am UTC](https://www.ruby-forum.com/t/mutablestring-vs-string/122359/3 "2007-12-07T00:02:38Z")

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You should return MutableStrings and also accept MutableStrings as  
parameters.

Tomas

From: removed\_email\_address@domain.invalid  
[[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)] On Behalf Of Eduardo A.  
Flores Verduzco  
Sent: Thursday, December 06, 2007 2:19 PM  
To: removed\_email\_address@domain.invalid  
Subject: Re: [Ironruby-core] MutableString vs string

Good question… I’m using always MutableString inside my StringIO  
implementation but I’m not sure if it’s ok…

On Dec 6, 2007 3:54 PM, Peter Bacon D. \<  
removed\_email\_address@domain.invalid[mailto:removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)\> wrote:

Along the lines of the discussion before about raising exceptions: Is it  
acceptable to return .NET strings from library methods or should we be  
trying to use MutableString instances?

Pete

---

<div class="post-metadata">

**Author:** ![editkid](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/e/977dab/32.png) [@editkid](https://www.ruby-forum.com/u/editkid)\
**Post date:** [December 7, 2007, 5:30am UTC](https://www.ruby-forum.com/t/mutablestring-vs-string/122359/4 "2007-12-07T05:30:36Z")

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Tomas:

> You should return MutableStrings and also accept MutableStrings as  
> parameters.

Yup.

Long term, we’ve talked about some action binder magic that would  
automatically convert MutableString \<-\> System.String for calling .NET  
methods. But that’s a long way off, so use MutableStrings for now.

- John