Mercurial > repos > bcclaywell > argo_navis

comparison venv/lib/python2.7/site-packages/yaml/reader.py @ 0:d67268158946 draft

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planemo upload commit a3f181f5f126803c654b3a66dd4e83a48f7e203b
author bcclaywell
date Mon, 12 Oct 2015 17:43:33 -0400
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-1:000000000000 0:d67268158946
1 # This module contains abstractions for the input stream. You don't have to
2 # looks further, there are no pretty code.
3 #
4 # We define two classes here.
5 #
6 # Mark(source, line, column)
7 # It's just a record and its only use is producing nice error messages.
8 # Parser does not use it for any other purposes.
9 #
10 # Reader(source, data)
11 # Reader determines the encoding of `data` and converts it to unicode.
12 # Reader provides the following methods and attributes:
13 # reader.peek(length=1) - return the next `length` characters
14 # reader.forward(length=1) - move the current position to `length` characters.
15 # reader.index - the number of the current character.
16 # reader.line, stream.column - the line and the column of the current character.
17
18 __all__ = ['Reader', 'ReaderError']
19
20 from error import YAMLError, Mark
21
22 import codecs, re
23
24 class ReaderError(YAMLError):
25
26 def __init__(self, name, position, character, encoding, reason):
27 self.name = name
28 self.character = character
29 self.position = position
30 self.encoding = encoding
31 self.reason = reason
32
33 def __str__(self):
34 if isinstance(self.character, str):
35 return "'%s' codec can't decode byte #x%02x: %s\n" \
36 " in \"%s\", position %d" \
37 % (self.encoding, ord(self.character), self.reason,
38 self.name, self.position)
39 else:
40 return "unacceptable character #x%04x: %s\n" \
41 " in \"%s\", position %d" \
42 % (self.character, self.reason,
43 self.name, self.position)
44
45 class Reader(object):
46 # Reader:
47 # - determines the data encoding and converts it to unicode,
48 # - checks if characters are in allowed range,
49 # - adds '\0' to the end.
50
51 # Reader accepts
52 # - a `str` object,
53 # - a `unicode` object,
54 # - a file-like object with its `read` method returning `str`,
55 # - a file-like object with its `read` method returning `unicode`.
56
57 # Yeah, it's ugly and slow.
58
59 def __init__(self, stream):
60 self.name = None
61 self.stream = None
62 self.stream_pointer = 0
63 self.eof = True
64 self.buffer = u''
65 self.pointer = 0
66 self.raw_buffer = None
67 self.raw_decode = None
68 self.encoding = None
69 self.index = 0
70 self.line = 0
71 self.column = 0
72 if isinstance(stream, unicode):
73 self.name = "<unicode string>"
74 self.check_printable(stream)
75 self.buffer = stream+u'\0'
76 elif isinstance(stream, str):
77 self.name = "<string>"
78 self.raw_buffer = stream
79 self.determine_encoding()
80 else:
81 self.stream = stream
82 self.name = getattr(stream, 'name', "<file>")
83 self.eof = False
84 self.raw_buffer = ''
85 self.determine_encoding()
86
87 def peek(self, index=0):
88 try:
89 return self.buffer[self.pointer+index]
90 except IndexError:
91 self.update(index+1)
92 return self.buffer[self.pointer+index]
93
94 def prefix(self, length=1):
95 if self.pointer+length >= len(self.buffer):
96 self.update(length)
97 return self.buffer[self.pointer:self.pointer+length]
98
99 def forward(self, length=1):
100 if self.pointer+length+1 >= len(self.buffer):
101 self.update(length+1)
102 while length:
103 ch = self.buffer[self.pointer]
104 self.pointer += 1
105 self.index += 1
106 if ch in u'\n\x85\u2028\u2029' \
107 or (ch == u'\r' and self.buffer[self.pointer] != u'\n'):
108 self.line += 1
109 self.column = 0
110 elif ch != u'\uFEFF':
111 self.column += 1
112 length -= 1
113
114 def get_mark(self):
115 if self.stream is None:
116 return Mark(self.name, self.index, self.line, self.column,
117 self.buffer, self.pointer)
118 else:
119 return Mark(self.name, self.index, self.line, self.column,
120 None, None)
121
122 def determine_encoding(self):
123 while not self.eof and len(self.raw_buffer) < 2:
124 self.update_raw()
125 if not isinstance(self.raw_buffer, unicode):
126 if self.raw_buffer.startswith(codecs.BOM_UTF16_LE):
127 self.raw_decode = codecs.utf_16_le_decode
128 self.encoding = 'utf-16-le'
129 elif self.raw_buffer.startswith(codecs.BOM_UTF16_BE):
130 self.raw_decode = codecs.utf_16_be_decode
131 self.encoding = 'utf-16-be'
132 else:
133 self.raw_decode = codecs.utf_8_decode
134 self.encoding = 'utf-8'
135 self.update(1)
136
137 NON_PRINTABLE = re.compile(u'[^\x09\x0A\x0D\x20-\x7E\x85\xA0-\uD7FF\uE000-\uFFFD]')
138 def check_printable(self, data):
139 match = self.NON_PRINTABLE.search(data)
140 if match:
141 character = match.group()
142 position = self.index+(len(self.buffer)-self.pointer)+match.start()
143 raise ReaderError(self.name, position, ord(character),
144 'unicode', "special characters are not allowed")
145
146 def update(self, length):
147 if self.raw_buffer is None:
148 return
149 self.buffer = self.buffer[self.pointer:]
150 self.pointer = 0
151 while len(self.buffer) < length:
152 if not self.eof:
153 self.update_raw()
154 if self.raw_decode is not None:
155 try:
156 data, converted = self.raw_decode(self.raw_buffer,
157 'strict', self.eof)
158 except UnicodeDecodeError, exc:
159 character = exc.object[exc.start]
160 if self.stream is not None:
161 position = self.stream_pointer-len(self.raw_buffer)+exc.start
162 else:
163 position = exc.start
164 raise ReaderError(self.name, position, character,
165 exc.encoding, exc.reason)
166 else:
167 data = self.raw_buffer
168 converted = len(data)
169 self.check_printable(data)
170 self.buffer += data
171 self.raw_buffer = self.raw_buffer[converted:]
172 if self.eof:
173 self.buffer += u'\0'
174 self.raw_buffer = None
175 break
176
177 def update_raw(self, size=1024):
178 data = self.stream.read(size)
179 if data:
180 self.raw_buffer += data
181 self.stream_pointer += len(data)
182 else:
183 self.eof = True
184
185 #try:
186 # import psyco
187 # psyco.bind(Reader)
188 #except ImportError:
189 # pass
190