Todo

TODO list for Perl module Object::LocalVars

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# Bugs to squash
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#--------------------------------------------------------------------------#
# Tests to write
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#--------------------------------------------------------------------------#
# Features for release soon
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- add introspection method to retrieve list of properties for a class

- EXPORT_OK a default BUILD that automatically populates from a hash_ref

- have property definitions take default value as argument e.g: :Prop( 12 ) or
  :Prop( [] ), etc.  *Don't* use package variable -- tempting, but vulnerable.

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# Potential incremental improvements for future releases
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- update benchmarks

- synonyms for :Prop (:Property :P) and :Method (:Meth :M) etc (:Public,
  :Private, :Protected)

- @array and %hash with :Prop, etc. attributes

- automethods

- naming $self as something else

- "super" like Spiffy does(?)

- mixin/trait support(?)

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# Ideas involving substantial API or structural change
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- switch from package globals for storing data to closures containing anonymous
  globrefs and coderefs (also need to move TRACKER to lexical closure in Object
  LocalVars)

- make attributes compatible with Attribute::Handlers -- should be OK as long
  as they only take effect in the BEGIN phase

- thread shared objects -- use Data::Uniqid or Data::UUID or equivalent to
  generate ID and store in a registry table (See below for ideas)  (VERY LOW
  PRIORITY)

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# Style thoughts -- refine for POD?
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Write about accessor style -- using name() and set_name().  If I ever
want to use name(index) or name(key) for @array and %hash property accessors,
then I need to not use name(val) to set scalars.  set_name should return the
object, to allow chaining.  

Mutators should be (to paraphrase Bill Clinton) "safe, legal and rare" so
maybe this doesn't matter much in the end.

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# Thoughts on thread safety and data sharing
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Problem of using refaddr has been solved since 0.13 using CLONE.

Sharing objects across threads seems much trickier.  First, the package globals
holding data all need to be shared.  Next, access has to be coordinated --
could be done with semaphors in the wrapper or locking the object tracker hash,
but that blocks everything on that object until the method exits (might be the
right thing to do.)  Accessors can lock the target before reading/writing the
same way.  Still ugly if accessing an array or hash-ref -- the method will have
to lock that, too, I think, or will have to get/store.  Alias of $self should
still be OK, as that's just aliasing a subroutine argument within the same
thread.

Smart thing to do is have Object::LocalVars automatically install the right
versions of locking/sharing subs or otherwise based on whether 
%INC{"threads/shared.pm"} is defined.  Otherwise, need an
Object::LocalVars::Shareable module that adds this functionality (at 
massive speed cost, I'd expect.)

Other potential snags:

- New objects created in one thread will still have data available in other
  threads due to shared data storage hashes, but won't be easily accessable.
  Would need to have a way to have a thread pass or return an object UUID to
  allow another thread to know what to manipulate. (This is probably fine.)

- Object destruction also becomes an issue -- can't destroy data when the
  reference count goes to zero because the object might exist in the other
  thread.  Have to disable DESTROY and have users manually destroy UUIDs when
  they are done with them, or have to keep object counts during CLONE, etc.  
  Perhaps keep a count of clones in a shared data structure and DESTROY is a
  no-op unless count is down to 1.  But what about new objects in a thread?  
  Data will be duplicated, and ID could have been passed over to other thread,
  so when does data get destroyed then?  Ugh.  If "new_from_id" is possible,
  then that could increment the count, I suppose.