Do parsing first

tts/text/input_parsing/parser.py

@@ -0,0 +1,47 @@
+"""
+Parse raw text sequences into Arpabet and Grapheme sequences so that they can be 
+treated independently.
+
+Inspired by and including code from original Tacotron2 by Keith Ito.
+"""
+
+import re
+
+# Regular expression matching text enclosed in curly braces:
+_curly_re = re.compile(r'(.*?)\{(.+?)\}(.*)')
+
+class ArpabetSequence:
+    def __init__(self, sequence):
+        self.sequence = sequence
+
+class GraphemeSquence:
+    def __init__(self, sequence):
+        self.sequence = sequence
+
+def parse_grapheme_and_arpabet_sequence(input_text):
+    """
+    Parse a string into an array of ArpabetSequence and GraphemeSequence so that each 
+    subsequence can be treated independently.
+    """
+    sequence = []
+
+    # Check for curly braces and treat their contents as ARPAbet:
+    while len(input_text):
+        input_text = input_text.strip()
+        m = _curly_re.match(input_text)
+        if not m:
+            sequence.append(GraphemeSquence(input_text))
+            break
+
+        before = m.group(1).strip()
+        bracketed = m.group(2).strip()
+        after = m.group(3).strip()
+
+        if before:
+            sequence.append(GraphemeSquence(before))
+        if bracketed:
+            sequence.append(ArpabetSequence(bracketed))
+
+        input_text = after
+
+    return sequence