GitLab

* Define new output dataclasses for greedy generation

* Add output_[...] flags in greedy generation methods

Added output_attentions, output_hidden_states, output_scores flags in
generate and greedy_search methods in GenerationMixin.

* [WIP] Implement logic and tests for output flags in generation

* Update GreedySearchOutput classes & docstring

* Implement greedy search output accumulation logic

Update greedy_search unittests

Fix generate method return value docstring

Properly init flags with the default config

* Update configuration to add output_scores flag

* Fix test_generation_utils

Sort imports and fix isinstance tests for GreedySearchOutputs

* Fix typo in generation_utils

* Add return_dict_in_generate for backwards compatibility

* Add return_dict_in_generate flag in config

* Fix tyPo in configuration

* Fix handling of attentions and hidden_states flags

* Make style & quality

* first attempt attentions

* some corrections

* improve tests

* special models requires special test

* disable xlm test for now

* clean tests

* fix for tf

* isort

* Add output dataclasses for other generation methods

* Add logic to return dict in sample generation

* Complete test for sample generation

- Pass output_attentions and output_hidden_states flags to encoder in
encoder-decoder models
- Fix import satements order in test_generation_utils file

* Add logic to return dict in sample generation

- Refactor tests to avoid using self.assertTrue, which provides
scarce information when the test fails
- Add tests for the three beam_search methods: vanilla, sample and
grouped

* Style doc

* Fix copy-paste error in generation tests

* Rename logits to scores and refactor

* Refactor group_beam_search for consistency

* make style

* add sequences_scores

* fix all tests

* add docs

* fix beam search finalize test

* correct docstring

* clean some files

* Made suggested changes to the documentation

* Style doc ?

* Style doc using the Python util

* Update src/transformers/generation_utils.py

* fix empty lines

* fix all test
Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>