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From Doug Cutting <cutt...@apache.org>
Subject Re: schema defaults not reflected in generated objects (1.3.2)
Date Mon, 07 Jun 2010 22:51:07 GMT
On 06/07/2010 03:40 PM, Scott Carey wrote:
> If the specific compiler generated a couple constructors --
> * A default empty argument constructor -- fills fields with defaults.
> * A constructor with all fields passed in -- assigns fields from the constructor and
does nothing with defaults.
>
> Then I can use the latter to avoid the performance issue.

A problem with the latter is that such constructors can be fragile.  If 
you have a number of integer fields and reorder them in your schema then 
the geneated constructor arguments will be re-ordered but the compiler 
will not notice a problem.

Another option might be to have a flag on the compiler to control 
generation of default value settings.

> FWIW, I have written wrappers around all of my datum classes to deal
> with this,

FWIW, Philip claims that (from his Google experience with protobufs) 
that the best practice is always to use a manually-written wrapper 
around generated classes.

> and I have wanted to either modify the SpecificCompiler or
> have a new generated object 'flavor' that had the safe-construction,
> union resolution, and getter methods that my wrappers provide.  I
> just haven't had time and its lower priority than some other
> enhancements I'll need soon.

Perhaps you can just post some pseudo code that illustrates what would 
be generated, for discussion?

For generated code like this I see no point to getter/setter methods. 
They seem equivalent to public fields.  But perhaps I'm missing something.

Doug


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