chromium/third_party/cld_3/src/src/embedding_feature_extractor.h

/* Copyright 2016 Google Inc. All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
==============================================================================*/

#ifndef EMBEDDING_FEATURE_EXTRACTOR_H_
#define EMBEDDING_FEATURE_EXTRACTOR_H_

#include <memory>
#include <string>
#include <vector>

#include "feature_extractor.h"
#include "task_context.h"
#include "workspace.h"

namespace chrome_lang_id {

// An EmbeddingFeatureExtractor manages the extraction of features for
// embedding-based models. It wraps a sequence of underlying classes of feature
// extractors, along with associated predicate maps. Each class of feature
// extractors is associated with a name, e.g., "unigrams", "bigrams".
//
// The class is split between a generic abstract version,
// GenericEmbeddingFeatureExtractor (that can be initialized without knowing the
// signature of the ExtractFeatures method) and a typed version.
//
// The predicate maps must be initialized before use: they can be loaded using
// Read() or updated via UpdateMapsForExample.
class GenericEmbeddingFeatureExtractor { … };

// Templated, object-specific implementation of the
// EmbeddingFeatureExtractor. EXTRACTOR should be a FeatureExtractor<OBJ,
// ARGS...> class that has the appropriate FeatureTraits() to ensure that
// locator type features work.
//
// Note: for backwards compatibility purposes, this always reads the FML spec
// from "<prefix>_features".
template <class EXTRACTOR, class OBJ, class... ARGS>
class EmbeddingFeatureExtractor : public GenericEmbeddingFeatureExtractor { … };

}  // namespace chrome_lang_id

#endif  // EMBEDDING_FEATURE_EXTRACTOR_H_