[Python-ideas] IntFlags

[Cameron Simpson]

On 05Mar2015 05:04, Neil Girdhar <mistersheik at gmail.com> wrote:
>This is exactly why we should not have & and ~.  It creates the possibility
>to write meaningless code.  Have methods that clear fields and methods that
>set them.  I proposed an interface to IntFields in another message.

I can see the argument against ~, unless you preagree a 1's complelment bit 
range (or equivalent, whatever): feasible, given that you might refuse to 
accept "unknown" flags. With a preagreed range, "~" is perfectly meaningful.

I do not see _any_ argument again "&". I would be very unhappy with an IntFlags 
that didn't accept "&" and "|", and immediately subclass it and never use the 
raw one again.

I'm not sure I am a fan of "remembering negation". Keep it simple. Forbid (or 
document as undefined) ~ in the absense of a range agreement at setup time.

Cheers,
Cameron Simpson <cs at zip.com.au>

Favourite proverb: Ein mann der motorrad fahrt ist fuer immer jung.