[Tutor] When are strings interned?
Angus Rodgers
angus at bigfoot.com
Fri Jul 3 13:46:06 CEST 2009
This is partly a test to see if I can reply in the correct format
to a message in the tutor list (which I receive in digest format).
>Date: Thu, 02 Jul 2009 20:39:28 +1000
>From: Lie Ryan <lie.1296 at gmail.com>
>
>Angus Rodgers wrote:
>[...]
>>>>> p = "green ideas"
>>>>> q = "green ideas"
>>>>> p == q
>> True
>>>>> p is q
>> False
>[...]
>In this particular case, the reason is because "colourless" can be used
>as an identifier.
>[...] Identifiers cannot contain spaces, that's why green ideas are
>not interned.
That is very clear, thanks.
Presumably a different optimisation is going on here:
>>> "green ideas" is "green ideas"
True
[Does it create confusion to quote a dialogue with the interpreter
in this way? The >>> looks like an instance of e-mail quotation.]
>And... have I told you not to rely on this behavior? NEVER rely on this
>implementation details. Once you get bitten by it, you'll regret it.
Noted!
--
Angus Rodgers
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