Add GNMT (dmlc#64)

* Add gnmt

* fix lint

* fix

* fix lint

* fix lint

* move to scripts

* fix

* fix

* fix

* specify beam_size

gluonnlp/model/attention_cell.py

@@ -132,7 +132,7 @@ def __call__(self, query, key, value=None, mask=None):  # pylint: disable=argume
         att_weights : Symbol or NDArray
             Attention weights. Shape (batch_size, query_length, memory_length)
         """
-        return super(AttentionCell, self).__call__(query, key, value, mask)
+        return self.forward(query, key, value, mask)
 
     def forward(self, query, key, value=None, mask=None):  # pylint: disable=arguments-differ
         if value is None:
@@ -242,7 +242,7 @@ def __call__(self, query, key, value=None, mask=None):
             Attention weights of multiple heads.
             Shape (batch_size, num_heads, query_length, memory_length)
         """
-        return super(MultiHeadAttentionCell, self).__call__(query, key, value, mask)
+        return self.forward(query, key, value, mask)
 
     def _compute_weight(self, F, query, key, mask=None):
         query = self.proj_query(query)  # Shape (batch_size, query_length, query_units)

scripts/nmt/_constants.py

@@ -0,0 +1,22 @@
+# coding: utf-8
+
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you 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.
+"""Constants used in the NMT examples."""
+import os
+
+CACHE_PATH = os.path.realpath(os.path.join(os.path.realpath(__file__), '..', 'cached'))

scripts/nmt/bleu.py

@@ -44,15 +44,16 @@ def _ngrams(segment, n):
     return ngram_counts
 
 
-def compute_bleu(reference_corpus, translation_corpus, max_n=4, smooth=False, lower_case=False):
+def compute_bleu(reference_corpus_list, translation_corpus,
+                 max_n=4, smooth=False, lower_case=False):
     """Compute bleu score of translation against references.
 
     Parameters
     ----------
-    reference_corpus: list(list(list(str)))
-        List of lists of references for each translation.
+    reference_corpus_list: list of list(list(str))
+        List of references for each translation.
     translation_corpus: list(list(str))
-        List of translations to score.
+        Translations to score.
     max_n: int, default 4
         Maximum n-gram order to use when computing BLEU score.
     smooth: bool, default False
@@ -65,13 +66,14 @@ def compute_bleu(reference_corpus, translation_corpus, max_n=4, smooth=False, lo
     5-Tuple with the BLEU score, n-gram precisions, brevity penalty,
         reference length, and translation length
     """
-    precision_numerators = Counter()
-    precision_denominators = Counter()
+    precision_numerators = [0 for _ in range(max_n)]
+    precision_denominators = [0 for _ in range(max_n)]
     ref_length, trans_length = 0, 0
-    assert len(reference_corpus) == len(translation_corpus), \
-        'The number of translations and their references do not match'
+    for references in reference_corpus_list:
+        assert len(references) == len(translation_corpus), \
+            'The number of translations and their references do not match'
 
-    for references, translation in zip(reference_corpus, translation_corpus):
+    for references, translation in zip(zip(*reference_corpus_list), translation_corpus):
         if lower_case:
             references = [list(map(str.lower, reference)) for reference in references]
             translation = list(map(str.lower, translation))