.. ops/index.rst

Core Ops
========

An ``Op``'s primary role is to function as a node in a directed acyclic graph 
dependency computation graph.  

*Core ops* are ops that are available and generally useful to all framework 
bridges and that can be compiled by all transformers. A framework bridge may 
define framework-specific ops to simplify graph construction, provided that the 
bridge can enable every transformer to replace all such ops with equivalent 
subgraphs composed of core ops. Similary, transformers may define 
transformer-specific ops to represent kernels or other intermediate operations. 

If a framework supports extending the set of ops it offers, a bridge may even 
expose transformer-specific ops to the framework user.

Our design philosophy is that the graph is not a script for running kernels; 
rather, our compilation will match ``ops`` to appropriate kernels for the 
backend(s) in use. Thus, we expect that adding of new Core ops should be 
infrequent and that most functionality instead gets added with new functions 
that build sub-graphs from existing core ops.   

It is easiest to define a new op by adapting an existing op. Some of the tasks 
that must be performed are:

- Op constructor:

  * Checking type-consistency of arguments 
  * Specifying the result type for a call 

- Serializer/Deserializer

- Transformer handlers:

  * Interpreter (reference) implementation of behavior. The
    implementation should favor clarity over efficiency.



Alphabetical list of Core ``ops``
----------------------------------

Not currently a comprehensive list.  


.. toctree::
   :maxdepth: 1

   abs.rst
   acos.rst
   add.rst
   asin.rst
   atan.rst
   avg_pool.rst
   avg_pool_backprop.rst
   broadcast.rst
   ceiling.rst
   concatenate.rst
   constant.rst
   convert.rst
   convolution.rst
   cos.rst
   cosh.rst

