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Date: Wed, 16 Mar 2016 17:00:39 -0500
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Subject: Re: [PHP-DEV] [RFC Discussion] Typed Properties
From: larry@garfieldtech.com (Larry Garfield)

On 3/16/16 2:30 PM, Andrey Andreev wrote:
> Also, a LOT of code would end up with e.g. a default value of 0 for an 
> integer property, still having to check if it was properly populated 
> with a positive value - not much of an improvement over NULLs. Cheers, 
> Andrey. 

That's fine.  Type checking doesn't say that a value is correct or 
meaningful; it just enforces the shape of the data.

Vis, type enforcement tells you that the property is an integer; it 
doesn't tell you that the integer is within the range of legal values 
for the temperature of a room.  It tells you that a property is a 
string; it doesn't tell you that the string doesn't contain NSFW words.  
Those are all application-level concerns, not type-level concerns, no 
matter what we do here.  (Just like they are for parameters and returns 
already.)

IMO, int/string/float is only a big deal on properties if you're using 
reflection for DB schema generation or similar, as it lets you remove an 
annotation.  (That's a useful benefit, though.)  The bigger impact for 
me is for class names, so I can enforce a given object type on a certain 
property.  Knowing "at least it's not NULL" has a much larger benefit in 
that case, as you avoid many "method called on non-object 100 execution 
lines later than the actual bug, good luck finding it" errors. :-)

-- 
--Larry Garfield