[libxml-devel] << operator

[Sean Chittenden]

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>>>> A contrived example, but this code absolutely irritates the shit  
>>>> out of me:
>>>> Class F
>>>> def a=(b)
>>>>   @z = b + 1
>>>>   return @z
>>>> end
>>>> def a
>>>>   return @z
>>>> end
>>>> end
>>>> f = F.new
>>>> x = f.a = 1
>>>> p f.a  # Prints 2
>>>> p x    # Prints 1
>>>
>>> That's bizarre.  What is going on there?  Print statement show  
>>> that def a= is called before def a, so can x ever be set to 1?
>> It's an "optimization".  The rvalue of an assignment is the  
>> argument to all lvalues in an assignment statement.  i.e.: x = f.a  
>> = 1 is translated into "x = 1 ; f.a = 1".  I think that was a very  
>> bad decision, but oh well.  Ruby ain't perfect and this, to me at  
>> least, is perfect justification for doing what is right vs. what is  
>> "standard."  -sc
>
> Ah.  That is silly.


And because it is a counterintuitive construct compared to nearly  
every other language on the planet, it is VERY difficult to figure out  
for the first time!!!!!  Ugh.  -sc

- --
Sean Chittenden
sean at chittenden.org



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