From 8d85af84cd5f1748f979fddcbc4aab1449f61ecb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Eren=20G=C3=B6lge?= <egolge@coqui.ai>
Date: Tue, 16 Nov 2021 13:28:42 +0100
Subject: [PATCH] Implement Punctuation class

---
 TTS/tts/utils/text/punctuation.py | 156 ++++++++++++++++++++++++++++++
 1 file changed, 156 insertions(+)
 create mode 100644 TTS/tts/utils/text/punctuation.py

diff --git a/TTS/tts/utils/text/punctuation.py b/TTS/tts/utils/text/punctuation.py
new file mode 100644
index 00000000..624cea88
--- /dev/null
+++ b/TTS/tts/utils/text/punctuation.py
@@ -0,0 +1,156 @@
+import collections
+import re
+from enum import Enum
+
+import six
+
+_DEF_PUNCS = ';:,.!?¡¿—…"«»“”'
+
+_PUNC_IDX = collections.namedtuple("_punc_index", ["punc", "position"])
+
+
+class PuncPosition(Enum):
+    """Enum for the punctuations positions"""
+
+    BEGIN = 0
+    END = 1
+    MIDDLE = 2
+    ALONE = 3
+
+
+class Punctuation:
+    """Handle punctuations characters in text.
+
+    Just strip punctuations from text or strip and restore them later.
+
+    Args:
+        puncs (str): The punctuations to be processed. Defaults to `_DEF_PUNCS`.
+    """
+
+    def __init__(self, puncs: str = _DEF_PUNCS):
+        self.puncs = puncs
+
+    @staticmethod
+    def default_puncs():
+        """Return default set of punctuations."""
+        return _DEF_PUNCS
+
+    @property
+    def puncs(self):
+        return self._puncs
+
+    @puncs.setter
+    def puncs(self, value):
+        if not isinstance(value, six.string_types):
+            raise ValueError("[!] Punctuations must be of type str.")
+        self._puncs = "".join(set(value))
+        self.puncs_regular_exp = re.compile(fr"(\s*[{re.escape(self._puncs)}]+\s*)+")
+
+    def strip(self, text):
+        """Remove all the punctuations by replacing with `space`.
+
+        Args:
+            text (str): The text to be processed.
+
+        Example::
+
+            "This is. example !" -> "This is example "
+        """
+        return re.sub(self.puncs_regular_exp, " ", text).strip()
+
+    def strip_to_restore(self, text):
+        """Remove punctuations from text to restore them later.
+
+        Args:
+            text (str): The text to be processed.
+
+        Examples ::
+
+            "This is. example !" -> [["This is", "example"], [".", "!"]]
+
+        """
+        text, puncs = self._strip_to_restore(text)
+        return text, puncs
+
+    def _strip_to_restore(self, text):
+        """Auxiliary method for Punctuation.preserve()"""
+        matches = list(re.finditer(self.puncs_regular_exp, text))
+        if not matches:
+            return [text], []
+        # the text is only punctuations
+        if len(matches) == 1 and matches[0].group() == text:
+            return [], [_PUNC_IDX(text, PuncPosition.ALONE)]
+        # build a punctuation map to be used later to restore punctuations
+        puncs = []
+        for match in matches:
+            position = PuncPosition.MIDDLE
+            if match == matches[0] and text.startswith(match.group()):
+                position = PuncPosition.BEGIN
+            elif match == matches[-1] and text.endswith(match.group()):
+                position = PuncPosition.END
+            puncs.append(_PUNC_IDX(match.group(), position))
+        # convert str text to a List[str], each item is separated by a punctuation
+        splitted_text = []
+        for punc in puncs:
+            split = text.split(punc.punc)
+            prefix, suffix = split[0], punc.punc.join(split[1:])
+            splitted_text.append(prefix)
+            text = suffix
+        return splitted_text, puncs
+
+    @classmethod
+    def restore(cls, text, puncs):
+        """Restore punctuation in a text.
+
+        Args:
+            text (str): The text to be processed.
+            puncs (List[str]): The list of punctuations map to be used for restoring.
+
+        Examples ::
+
+            ['This is', 'example'], ['.', '!'] -> "This is. example!"
+
+        """
+        return cls._restore(text, puncs, 0)
+
+    @classmethod
+    def _restore(cls, text, puncs, num):
+        """Auxiliary method for Punctuation.restore()"""
+        if not puncs:
+            return text
+
+        # nothing have been phonemized, returns the puncs alone
+        if not text:
+            return ["".join(m.mark for m in puncs)]
+
+        current = puncs[0]
+
+        if current.position == PuncPosition.BEGIN:
+            return cls._restore([current.mark + text[0]] + text[1:], puncs[1:], num)
+
+        if current.position == PuncPosition.END:
+            return [text[0] + current.punc] + cls._restore(text[1:], puncs[1:], num + 1)
+
+        if current.position == PuncPosition.ALONE:
+            return [current.mark] + cls._restore(text, puncs[1:], num + 1)
+
+        # POSITION == MIDDLE
+        if len(text) == 1:  # pragma: nocover
+            # a corner case where the final part of an intermediate
+            # mark (I) has not been phonemized
+            return cls._restore([text[0] + current.punc], puncs[1:], num)
+
+        return cls._restore([text[0] + current.punc + text[1]] + text[2:], puncs[1:], num)
+
+
+if __name__ == "__main__":
+    punc = Punctuation()
+    text = "This is. This is, example!"
+
+    print(punc.strip(text))
+
+    split_text, puncs = punc.strip_to_restore(text)
+    print(split_text, " ---- ", puncs)
+
+    restored_text = punc.restore(split_text, puncs)
+    print(restored_text)