.. _program_listing_file_src_layers_output.h:

Program Listing for File output.h
=================================

|exhale_lsh| :ref:`Return to documentation for file <file_src_layers_output.h>` (``src/layers/output.h``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #pragma once
   
   #include "data/shortlist.h"
   #include "generic.h"
   #include "layers/factory.h"
   #include "logits.h"
   #include "marian.h"
   
   namespace marian {
   
   namespace mlp {
   
   class Output : public LayerBase, public IUnaryLogitLayer, public IHasShortList {
   private:
     // parameters held by this layer
     Expr Wt_;  // weight matrix is stored transposed for efficiency
     Expr b_;
     Expr lemmaEt_;  // re-embedding matrix for lemmas [lemmaDimEmb x lemmaVocabSize]
     bool isLegacyUntransposedW{false};  // legacy-model emulation: W is stored in non-transposed form
     bool hasBias_{true};
   
     Ptr<FactoredVocab> factoredVocab_;
   
     // optional parameters set/updated after construction
     Expr tiedParam_;
     Ptr<data::Shortlist> shortlist_;
   
     void lazyConstruct(int inputDim);
   
   public:
     Output(Ptr<ExpressionGraph> graph, Ptr<Options> options)
         : LayerBase(graph, options), hasBias_{!options->get<bool>("output-omit-bias", false)} {
       clear();
     }
   
     void tieTransposed(Expr tied) {
       if(Wt_)
         ABORT_IF(tiedParam_.get() != tied.get(),
                  "Tied output projection cannot be changed once weights have been created");
       else
         tiedParam_ = tied;
     }
   
     void setShortlist(Ptr<data::Shortlist> shortlist) override final {
       if(shortlist_)
         ABORT_IF(shortlist.get() != shortlist_.get(),
                  "Output shortlist cannot be changed except after clear()");
       else {
         shortlist_ = shortlist;
       }
       // cachedShortWt_ and cachedShortb_ will be created lazily inside apply()
     }
   
     // this is expected to be called in sync with graph->clear(), which invalidates
     // cachedShortWt_ etc. in the graph's short-term cache
     void clear() override final {
       shortlist_ = nullptr;
     }
   
     Logits applyAsLogits(Expr input) override final;
   };
   
   }  // namespace mlp
   
   }  // namespace marian