Re: [Scheme-reports] Fwd: fresh empty strings

[Per Bothner <per@x>]

On 01/21/2012 09:54 AM, Vincent Manis wrote:
> My sense of the Scheme consensus on this issue is that empty lists are always eq, but whether empty other things are eq is unspecified. Am I correct?

Note the cases of mutable string and immutable strings should be 
distinguished.
Likewise for vectors.  I feel it should be:

(eq? "" "") --> unspecified
(eq? (string) (string)) --> #f
(eq? #() #()) --> unspecified
(eq? (vector) (vector)) --> #f

At least as long as the (string) constructor is defined to create a
mutable string, then each call creates a distinct strong object -
even in the zero-length case.
-- 
	--Per Bothner
per@x   http://per.bothner.com/

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