Mercurial > repos > shellac > guppy_basecaller

comparison env/lib/python3.7/site-packages/chardet/codingstatemachine.py @ 0:26e78fe6e8c4 draft

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"planemo upload commit c699937486c35866861690329de38ec1a5d9f783"
author shellac
date Sat, 02 May 2020 07:14:21 -0400
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-1:000000000000 0:26e78fe6e8c4
1 ######################## BEGIN LICENSE BLOCK ########################
2 # The Original Code is mozilla.org code.
3 #
4 # The Initial Developer of the Original Code is
5 # Netscape Communications Corporation.
6 # Portions created by the Initial Developer are Copyright (C) 1998
7 # the Initial Developer. All Rights Reserved.
8 #
9 # Contributor(s):
10 # Mark Pilgrim - port to Python
11 #
12 # This library is free software; you can redistribute it and/or
13 # modify it under the terms of the GNU Lesser General Public
14 # License as published by the Free Software Foundation; either
15 # version 2.1 of the License, or (at your option) any later version.
16 #
17 # This library is distributed in the hope that it will be useful,
18 # but WITHOUT ANY WARRANTY; without even the implied warranty of
19 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 # Lesser General Public License for more details.
21 #
22 # You should have received a copy of the GNU Lesser General Public
23 # License along with this library; if not, write to the Free Software
24 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
25 # 02110-1301 USA
26 ######################### END LICENSE BLOCK #########################
27
28 import logging
29
30 from .enums import MachineState
31
32
33 class CodingStateMachine(object):
34 """
35 A state machine to verify a byte sequence for a particular encoding. For
36 each byte the detector receives, it will feed that byte to every active
37 state machine available, one byte at a time. The state machine changes its
38 state based on its previous state and the byte it receives. There are 3
39 states in a state machine that are of interest to an auto-detector:
40
41 START state: This is the state to start with, or a legal byte sequence
42 (i.e. a valid code point) for character has been identified.
43
44 ME state: This indicates that the state machine identified a byte sequence
45 that is specific to the charset it is designed for and that
46 there is no other possible encoding which can contain this byte
47 sequence. This will to lead to an immediate positive answer for
48 the detector.
49
50 ERROR state: This indicates the state machine identified an illegal byte
51 sequence for that encoding. This will lead to an immediate
52 negative answer for this encoding. Detector will exclude this
53 encoding from consideration from here on.
54 """
55 def __init__(self, sm):
56 self._model = sm
57 self._curr_byte_pos = 0
58 self._curr_char_len = 0
59 self._curr_state = None
60 self.logger = logging.getLogger(__name__)
61 self.reset()
62
63 def reset(self):
64 self._curr_state = MachineState.START
65
66 def next_state(self, c):
67 # for each byte we get its class
68 # if it is first byte, we also get byte length
69 byte_class = self._model['class_table'][c]
70 if self._curr_state == MachineState.START:
71 self._curr_byte_pos = 0
72 self._curr_char_len = self._model['char_len_table'][byte_class]
73 # from byte's class and state_table, we get its next state
74 curr_state = (self._curr_state * self._model['class_factor']
75 + byte_class)
76 self._curr_state = self._model['state_table'][curr_state]
77 self._curr_byte_pos += 1
78 return self._curr_state
79
80 def get_current_charlen(self):
81 return self._curr_char_len
82
83 def get_coding_state_machine(self):
84 return self._model['name']
85
86 @property
87 def language(self):
88 return self._model['language']