import pynini
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from fun_text_processing.text_normalization.en.graph_utils import DAMO_UPPER, GraphFst, insert_space
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from pynini.lib import pynutil
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class AbbreviationFst(GraphFst):
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"""
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Finite state transducer for classifying electronic: as URLs, email addresses, etc.
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e.g. "ABC" -> tokens { abbreviation { value: "A B C" } }
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Args:
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whitelist: whitelist FST
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deterministic: if True will provide a single transduction option,
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for False multiple transduction are generated (used for audio-based normalization)
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"""
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def __init__(self, whitelist: "pynini.FstLike", deterministic: bool = True):
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super().__init__(name="abbreviation", kind="classify", deterministic=deterministic)
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dot = pynini.accep(".")
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# A.B.C. -> A. B. C.
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graph = DAMO_UPPER + dot + pynini.closure(insert_space + DAMO_UPPER + dot, 1)
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# A.B.C. -> A.B.C.
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graph |= DAMO_UPPER + dot + pynini.closure(DAMO_UPPER + dot, 1)
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# ABC -> A B C
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graph |= DAMO_UPPER + pynini.closure(insert_space + DAMO_UPPER, 1)
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# exclude words that are included in the whitelist
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graph = pynini.compose(
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pynini.difference(
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pynini.project(graph, "input"), pynini.project(whitelist.graph, "input")
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),
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graph,
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)
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graph = pynutil.insert('value: "') + graph.optimize() + pynutil.insert('"')
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graph = self.add_tokens(graph)
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self.fst = graph.optimize()
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