Updated vocab and vectors with forward method (pytorch#953)

* Updated vocab and vectors with forward method

* Added tests

test/experimental/test_vectors.py

@@ -71,6 +71,24 @@ def test_vectors_jit(self):
         self.assertEqual(vectors_obj['b'], jit_vectors_obj['b'])
         self.assertEqual(vectors_obj['not_in_it'], jit_vectors_obj['not_in_it'])
 
+    def test_vectors_forward(self):
+        tensorA = torch.tensor([1, 0], dtype=torch.float)
+        tensorB = torch.tensor([0, 1], dtype=torch.float)
+
+        unk_tensor = torch.tensor([0, 0], dtype=torch.float)
+        tokens = ['a', 'b']
+        vecs = torch.stack((tensorA, tensorB), 0)
+        vectors_obj = vectors(tokens, vecs, unk_tensor=unk_tensor)
+        jit_vectors_obj = torch.jit.script(vectors_obj.to_ivalue())
+
+        tokens_to_lookup = ['a', 'b', 'c']
+        expected_vectors = torch.stack((tensorA, tensorB, unk_tensor), 0)
+        vectors_by_tokens = vectors_obj(tokens_to_lookup)
+        jit_vectors_by_tokens = jit_vectors_obj(tokens_to_lookup)
+
+        self.assertEqual(expected_vectors, vectors_by_tokens)
+        self.assertEqual(expected_vectors, jit_vectors_by_tokens)
+
     def test_vectors_lookup_vectors(self):
         tensorA = torch.tensor([1, 0], dtype=torch.float)
         tensorB = torch.tensor([0, 1], dtype=torch.float)

test/experimental/test_vocab.py

@@ -119,6 +119,20 @@ def test_vocab_jit(self):
         self.assertEqual(jit_v.get_itos(), expected_itos)
         self.assertEqual(dict(jit_v.get_stoi()), expected_stoi)
 
+    def test_vocab_forward(self):
+        token_to_freq = {'a': 2, 'b': 2, 'c': 2}
+        sorted_by_freq_tuples = sorted(token_to_freq.items(), key=lambda x: x[1], reverse=True)
+
+        c = OrderedDict(sorted_by_freq_tuples)
+        v = vocab(c)
+        jit_v = torch.jit.script(v.to_ivalue())
+
+        tokens = ['b', 'a', 'c']
+        expected_indices = [2, 1, 3]
+
+        self.assertEqual(v(tokens), expected_indices)
+        self.assertEqual(jit_v(tokens), expected_indices)
+
     def test_vocab_lookup_token(self):
         token_to_freq = {'a': 2, 'b': 2, 'c': 2}
         sorted_by_freq_tuples = sorted(token_to_freq.items(), key=lambda x: x[1], reverse=True)

torchtext/experimental/vectors.py

@@ -203,7 +203,7 @@ def is_jitable(self):
         return not isinstance(self.vectors, VectorsPybind)
 
     @torch.jit.export
-    def __call__(self, tokens: List[str]) -> Tensor:
+    def forward(self, tokens: List[str]) -> Tensor:
         r"""Calls the `lookup_vectors` method
          Args:
             tokens: a list of tokens

torchtext/experimental/vocab.py

@@ -128,7 +128,7 @@ def is_jitable(self):
         return not isinstance(self.vocab, VocabPybind)
 
     @torch.jit.export
-    def __call__(self, tokens: List[str]) -> List[int]:
+    def forward(self, tokens: List[str]) -> List[int]:
         r"""Calls the `lookup_indices` method
         Args:
             tokens (List[str]): the tokens used to lookup their corresponding `indices`.