From a6e520e99a4075bc99ec1df52e4ebf7c1ee01cd9 Mon Sep 17 00:00:00 2001
From: Izen <speedcell4@users.noreply.github.com>
Date: Fri, 1 Feb 2019 21:28:23 +0900
Subject: [PATCH] fix parameter specials in Field.build_vocab (#495)

* fix parameter specials in Field.build_vocab
---
 test/data/test_field.py | 19 ++++++++++---------
 torchtext/data/field.py |  2 +-
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/test/data/test_field.py b/test/data/test_field.py
index 29c7be5274..1b734b6d9b 100644
--- a/test/data/test_field.py
+++ b/test/data/test_field.py
@@ -154,19 +154,20 @@ def test_build_vocab(self):
             fields=json_fields)
 
         # Test build_vocab default
-        question_field.build_vocab(tsv_dataset, json_dataset)
+        question_field.build_vocab(tsv_dataset, json_dataset, specials=['<space>'])
         assert question_field.vocab.freqs == Counter(
             {'When': 4, 'do': 4, 'you': 4, 'use': 4, 'instead': 4,
              'of': 4, 'was': 4, 'Lincoln': 4, 'born?': 4, 'シ': 2,
              'し?': 2, 'Where': 2, 'What': 2, 'is': 2, '2+2': 2,
              '"&"': 2, '"and"?': 2, 'Which': 2, 'location': 2,
              'Abraham': 2, '2+2=?': 2})
-        expected_stoi = {'<unk>': 0, '<pad>': 1, 'Lincoln': 2, 'When': 3,
-                         'born?': 4, 'do': 5, 'instead': 6, 'of': 7,
-                         'use': 8, 'was': 9, 'you': 10, '"&"': 11,
-                         '"and"?': 12, '2+2': 13, '2+2=?': 14, 'Abraham': 15,
-                         'What': 16, 'Where': 17, 'Which': 18, 'is': 19,
-                         'location': 20, 'し?': 21, 'シ': 22}
+        expected_stoi = {'<unk>': 0, '<pad>': 1, '<space>': 2,
+                         'Lincoln': 3, 'When': 4,
+                         'born?': 5, 'do': 6, 'instead': 7, 'of': 8,
+                         'use': 9, 'was': 10, 'you': 11, '"&"': 12,
+                         '"and"?': 13, '2+2': 14, '2+2=?': 15, 'Abraham': 16,
+                         'What': 17, 'Where': 18, 'Which': 19, 'is': 20,
+                         'location': 21, 'し?': 22, 'シ': 23}
         assert dict(question_field.vocab.stoi) == expected_stoi
         # Turn the stoi dictionary into an itos list
         expected_itos = [x[0] for x in sorted(expected_stoi.items(),
@@ -348,9 +349,9 @@ def test_numericalize_stop_words(self):
         test_example_data = question_field.pad(
             [question_field.preprocess(x) for x in
              [["When", "do", "you", "use", "シ",
-              "instead", "of", "し?"],
+               "instead", "of", "し?"],
               ["What", "is", "2+2", "<pad>", "<pad>",
-              "<pad>", "<pad>", "<pad>"],
+               "<pad>", "<pad>", "<pad>"],
               ["Here", "is", "a", "sentence", "with",
                "some", "oovs", "<pad>"]]]
         )
diff --git a/torchtext/data/field.py b/torchtext/data/field.py
index 0311bfcf88..090821b315 100644
--- a/torchtext/data/field.py
+++ b/torchtext/data/field.py
@@ -304,7 +304,7 @@ def build_vocab(self, *args, **kwargs):
                     counter.update(chain.from_iterable(x))
         specials = list(OrderedDict.fromkeys(
             tok for tok in [self.unk_token, self.pad_token, self.init_token,
-                            self.eos_token]
+                            self.eos_token] + kwargs.pop('specials', [])
             if tok is not None))
         self.vocab = self.vocab_cls(counter, specials=specials, **kwargs)