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1 # Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0 |
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2 # For details: https://bitbucket.org/ned/coveragepy/src/default/NOTICE.txt |
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3 |
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4 """Better tokenizing for coverage.py.""" |
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5 |
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6 import codecs |
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7 import keyword |
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8 import re |
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9 import sys |
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10 import token |
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11 import tokenize |
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12 |
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13 from coverage import env |
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14 from coverage.backward import iternext, unicode_class |
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15 from coverage.misc import contract |
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16 |
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17 |
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18 def phys_tokens(toks): |
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19 """Return all physical tokens, even line continuations. |
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20 |
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21 tokenize.generate_tokens() doesn't return a token for the backslash that |
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22 continues lines. This wrapper provides those tokens so that we can |
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23 re-create a faithful representation of the original source. |
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24 |
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25 Returns the same values as generate_tokens() |
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26 |
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27 """ |
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28 last_line = None |
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29 last_lineno = -1 |
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30 last_ttype = None |
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31 for ttype, ttext, (slineno, scol), (elineno, ecol), ltext in toks: |
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32 if last_lineno != elineno: |
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33 if last_line and last_line.endswith("\\\n"): |
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34 # We are at the beginning of a new line, and the last line |
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35 # ended with a backslash. We probably have to inject a |
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36 # backslash token into the stream. Unfortunately, there's more |
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37 # to figure out. This code:: |
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38 # |
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39 # usage = """\ |
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40 # HEY THERE |
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41 # """ |
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42 # |
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43 # triggers this condition, but the token text is:: |
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44 # |
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45 # '"""\\\nHEY THERE\n"""' |
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46 # |
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47 # so we need to figure out if the backslash is already in the |
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48 # string token or not. |
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49 inject_backslash = True |
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50 if last_ttype == tokenize.COMMENT: |
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51 # Comments like this \ |
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52 # should never result in a new token. |
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53 inject_backslash = False |
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54 elif ttype == token.STRING: |
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55 if "\n" in ttext and ttext.split('\n', 1)[0][-1] == '\\': |
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56 # It's a multi-line string and the first line ends with |
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57 # a backslash, so we don't need to inject another. |
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58 inject_backslash = False |
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59 if inject_backslash: |
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60 # Figure out what column the backslash is in. |
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61 ccol = len(last_line.split("\n")[-2]) - 1 |
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62 # Yield the token, with a fake token type. |
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63 yield ( |
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64 99999, "\\\n", |
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65 (slineno, ccol), (slineno, ccol+2), |
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66 last_line |
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67 ) |
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68 last_line = ltext |
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69 last_ttype = ttype |
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70 yield ttype, ttext, (slineno, scol), (elineno, ecol), ltext |
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71 last_lineno = elineno |
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72 |
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73 |
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74 @contract(source='unicode') |
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75 def source_token_lines(source): |
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76 """Generate a series of lines, one for each line in `source`. |
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77 |
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78 Each line is a list of pairs, each pair is a token:: |
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79 |
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80 [('key', 'def'), ('ws', ' '), ('nam', 'hello'), ('op', '('), ... ] |
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81 |
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82 Each pair has a token class, and the token text. |
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83 |
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84 If you concatenate all the token texts, and then join them with newlines, |
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85 you should have your original `source` back, with two differences: |
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86 trailing whitespace is not preserved, and a final line with no newline |
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87 is indistinguishable from a final line with a newline. |
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88 |
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89 """ |
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90 |
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91 ws_tokens = set([token.INDENT, token.DEDENT, token.NEWLINE, tokenize.NL]) |
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92 line = [] |
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93 col = 0 |
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94 |
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95 source = source.expandtabs(8).replace('\r\n', '\n') |
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96 tokgen = generate_tokens(source) |
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97 |
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98 for ttype, ttext, (_, scol), (_, ecol), _ in phys_tokens(tokgen): |
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99 mark_start = True |
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100 for part in re.split('(\n)', ttext): |
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101 if part == '\n': |
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102 yield line |
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103 line = [] |
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104 col = 0 |
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105 mark_end = False |
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106 elif part == '': |
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107 mark_end = False |
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108 elif ttype in ws_tokens: |
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109 mark_end = False |
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110 else: |
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111 if mark_start and scol > col: |
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112 line.append(("ws", u" " * (scol - col))) |
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113 mark_start = False |
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114 tok_class = tokenize.tok_name.get(ttype, 'xx').lower()[:3] |
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115 if ttype == token.NAME and keyword.iskeyword(ttext): |
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116 tok_class = "key" |
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117 line.append((tok_class, part)) |
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118 mark_end = True |
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119 scol = 0 |
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120 if mark_end: |
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121 col = ecol |
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122 |
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123 if line: |
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124 yield line |
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125 |
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126 |
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127 class CachedTokenizer(object): |
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128 """A one-element cache around tokenize.generate_tokens. |
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129 |
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130 When reporting, coverage.py tokenizes files twice, once to find the |
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131 structure of the file, and once to syntax-color it. Tokenizing is |
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132 expensive, and easily cached. |
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133 |
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134 This is a one-element cache so that our twice-in-a-row tokenizing doesn't |
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135 actually tokenize twice. |
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136 |
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137 """ |
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138 def __init__(self): |
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139 self.last_text = None |
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140 self.last_tokens = None |
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141 |
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142 @contract(text='unicode') |
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143 def generate_tokens(self, text): |
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144 """A stand-in for `tokenize.generate_tokens`.""" |
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145 if text != self.last_text: |
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146 self.last_text = text |
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147 readline = iternext(text.splitlines(True)) |
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148 self.last_tokens = list(tokenize.generate_tokens(readline)) |
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149 return self.last_tokens |
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150 |
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151 # Create our generate_tokens cache as a callable replacement function. |
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152 generate_tokens = CachedTokenizer().generate_tokens |
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153 |
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154 |
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155 COOKIE_RE = re.compile(r"^[ \t]*#.*coding[:=][ \t]*([-\w.]+)", flags=re.MULTILINE) |
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156 |
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157 @contract(source='bytes') |
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158 def _source_encoding_py2(source): |
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159 """Determine the encoding for `source`, according to PEP 263. |
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160 |
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161 `source` is a byte string, the text of the program. |
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162 |
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163 Returns a string, the name of the encoding. |
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164 |
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165 """ |
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166 assert isinstance(source, bytes) |
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167 |
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168 # Do this so the detect_encode code we copied will work. |
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169 readline = iternext(source.splitlines(True)) |
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170 |
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171 # This is mostly code adapted from Py3.2's tokenize module. |
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172 |
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173 def _get_normal_name(orig_enc): |
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174 """Imitates get_normal_name in tokenizer.c.""" |
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175 # Only care about the first 12 characters. |
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176 enc = orig_enc[:12].lower().replace("_", "-") |
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177 if re.match(r"^utf-8($|-)", enc): |
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178 return "utf-8" |
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179 if re.match(r"^(latin-1|iso-8859-1|iso-latin-1)($|-)", enc): |
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180 return "iso-8859-1" |
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181 return orig_enc |
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182 |
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183 # From detect_encode(): |
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184 # It detects the encoding from the presence of a UTF-8 BOM or an encoding |
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185 # cookie as specified in PEP-0263. If both a BOM and a cookie are present, |
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186 # but disagree, a SyntaxError will be raised. If the encoding cookie is an |
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187 # invalid charset, raise a SyntaxError. Note that if a UTF-8 BOM is found, |
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188 # 'utf-8-sig' is returned. |
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189 |
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190 # If no encoding is specified, then the default will be returned. |
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191 default = 'ascii' |
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192 |
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193 bom_found = False |
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194 encoding = None |
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195 |
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196 def read_or_stop(): |
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197 """Get the next source line, or ''.""" |
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198 try: |
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199 return readline() |
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200 except StopIteration: |
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201 return '' |
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202 |
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203 def find_cookie(line): |
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204 """Find an encoding cookie in `line`.""" |
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205 try: |
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206 line_string = line.decode('ascii') |
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207 except UnicodeDecodeError: |
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208 return None |
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209 |
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210 matches = COOKIE_RE.findall(line_string) |
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211 if not matches: |
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212 return None |
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213 encoding = _get_normal_name(matches[0]) |
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214 try: |
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215 codec = codecs.lookup(encoding) |
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216 except LookupError: |
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217 # This behavior mimics the Python interpreter |
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218 raise SyntaxError("unknown encoding: " + encoding) |
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219 |
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220 if bom_found: |
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221 # codecs in 2.3 were raw tuples of functions, assume the best. |
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222 codec_name = getattr(codec, 'name', encoding) |
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223 if codec_name != 'utf-8': |
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224 # This behavior mimics the Python interpreter |
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225 raise SyntaxError('encoding problem: utf-8') |
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226 encoding += '-sig' |
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227 return encoding |
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228 |
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229 first = read_or_stop() |
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230 if first.startswith(codecs.BOM_UTF8): |
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231 bom_found = True |
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232 first = first[3:] |
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233 default = 'utf-8-sig' |
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234 if not first: |
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235 return default |
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236 |
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237 encoding = find_cookie(first) |
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238 if encoding: |
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239 return encoding |
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240 |
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241 second = read_or_stop() |
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242 if not second: |
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243 return default |
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244 |
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245 encoding = find_cookie(second) |
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246 if encoding: |
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247 return encoding |
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248 |
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249 return default |
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250 |
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251 |
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252 @contract(source='bytes') |
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253 def _source_encoding_py3(source): |
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254 """Determine the encoding for `source`, according to PEP 263. |
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255 |
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256 `source` is a byte string: the text of the program. |
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257 |
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258 Returns a string, the name of the encoding. |
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259 |
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260 """ |
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261 readline = iternext(source.splitlines(True)) |
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262 return tokenize.detect_encoding(readline)[0] |
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263 |
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264 |
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265 if env.PY3: |
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266 source_encoding = _source_encoding_py3 |
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267 else: |
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268 source_encoding = _source_encoding_py2 |
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269 |
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270 |
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271 @contract(source='unicode') |
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272 def compile_unicode(source, filename, mode): |
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273 """Just like the `compile` builtin, but works on any Unicode string. |
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274 |
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275 Python 2's compile() builtin has a stupid restriction: if the source string |
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276 is Unicode, then it may not have a encoding declaration in it. Why not? |
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277 Who knows! It also decodes to utf8, and then tries to interpret those utf8 |
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278 bytes according to the encoding declaration. Why? Who knows! |
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279 |
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280 This function neuters the coding declaration, and compiles it. |
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281 |
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282 """ |
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283 source = neuter_encoding_declaration(source) |
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284 if env.PY2 and isinstance(filename, unicode_class): |
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285 filename = filename.encode(sys.getfilesystemencoding(), "replace") |
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286 code = compile(source, filename, mode) |
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287 return code |
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288 |
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289 |
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290 @contract(source='unicode', returns='unicode') |
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291 def neuter_encoding_declaration(source): |
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292 """Return `source`, with any encoding declaration neutered.""" |
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293 if COOKIE_RE.search(source): |
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294 source_lines = source.splitlines(True) |
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295 for lineno in range(min(2, len(source_lines))): |
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296 source_lines[lineno] = COOKIE_RE.sub("# (deleted declaration)", source_lines[lineno]) |
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297 source = "".join(source_lines) |
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298 return source |