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Date: Fri, 15 Feb 2013 19:25:12 -0500
Reply-To: Sanford Whiteman <swhitemanlistens-software@cypressintegrated.com>
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Subject: Re: [PHP-DEV] Questions regarding DateTimeImmutable
From: swhitemanlistens-software@cypressintegrated.com (Sanford Whiteman)

I think it was done to ease adoption even though it was known to
violate LSP. To quote Stas, "As for established practice, everybody
expects DateTime, so IMHO we should leave DateTime as base class even
though it's not strictly OO-pure."

This way does let users sub in DateTimeImmutable more easily and patch
over a ton of unintended -- maybe not even fully noted or understood
-- defects in their apps? I dunno.

I looked at the first discussion from late 2010 after Benjamin E.
sketched out the language addition and Larry G. suggested making them
siblings as opposed to subclassing, but those discussions seemed to
peter out and by the time Derick wrote the patch, the class model was
kind of accepted.

The discussion from 2012 is rather mild considering some pretty
disparate viewpoints are represented, viz. users don't care about
mutability vs. users have been coding as if DT were immutable.

-- Sandy