[Python-Dev] Surely "nullable" is a reasonable name?

Larry Hastings larry at hastings.org
Sat Apr 25 09:58:58 CEST 2015



On 04/24/2015 09:45 PM, Nick Coghlan wrote:
> Ah, I misread Tal's suggestion. Using unary + is an even neater approach.

Not exactly.  The way I figure it, the best way to achieve this with 
unary plus is to ast.parse it (as we currently do) and then modify the 
parse tree.  That works but it's kind of messy.

My main objection to this notation is that that set objects /don't 
support +./  The union operator for sets is |.

I've prototyped a hack allowing
     str(accept|={NoneType})
I used the tokenize module to tokenize, modify, and untokenize the 
converter invocation.  Works fine.  And since augmented assignment is 
(otherwise) illegal in expressions, it's totally unambiguous.  I think 
if we do it at all it should be with that notation.


//arry/


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