1 | # $Id: SourceReader.py,v 1.15 2007/04/03 01:57:42 tavis_rudd Exp $ |
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2 | """SourceReader class for Cheetah's Parser and CodeGenerator |
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3 | |
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4 | Meta-Data |
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5 | ================================================================================ |
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6 | Author: Tavis Rudd <tavis@damnsimple.com> |
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7 | License: This software is released for unlimited distribution under the |
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8 | terms of the MIT license. See the LICENSE file. |
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9 | Version: $Revision: 1.15 $ |
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10 | Start Date: 2001/09/19 |
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11 | Last Revision Date: $Date: 2007/04/03 01:57:42 $ |
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12 | """ |
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13 | __author__ = "Tavis Rudd <tavis@damnsimple.com>" |
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14 | __revision__ = "$Revision: 1.15 $"[11:-2] |
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15 | |
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16 | import re |
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17 | import sys |
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18 | |
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19 | EOLre = re.compile(r'[ \f\t]*(?:\r\n|\r|\n)') |
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20 | EOLZre = re.compile(r'(?:\r\n|\r|\n|\Z)') |
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21 | ENCODINGsearch = re.compile("coding[=:]\s*([-\w.]+)").search |
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22 | |
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23 | class Error(Exception): |
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24 | pass |
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25 | |
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26 | class SourceReader: |
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27 | def __init__(self, src, filename=None, breakPoint=None, encoding=None): |
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28 | |
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29 | ## @@TR 2005-01-17: the following comes from a patch Terrel Shumway |
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30 | ## contributed to add unicode support to the reading of Cheetah source |
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31 | ## files with dynamically compiled templates. All the existing unit |
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32 | ## tests pass but, it needs more testing and some test cases of its |
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33 | ## own. My instinct is to move this up into the code that passes in the |
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34 | ## src string rather than leaving it here. As implemented here it |
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35 | ## forces all src strings to unicode, which IMO is not what we want. |
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36 | # if encoding is None: |
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37 | # # peek at the encoding in the first two lines |
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38 | # m = EOLZre.search(src) |
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39 | # pos = m.end() |
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40 | # if pos<len(src): |
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41 | # m = EOLZre.search(src,pos) |
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42 | # pos = m.end() |
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43 | # m = ENCODINGsearch(src,0,pos) |
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44 | # if m: |
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45 | # encoding = m.group(1) |
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46 | # else: |
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47 | # encoding = sys.getfilesystemencoding() |
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48 | # self._encoding = encoding |
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49 | # if type(src) is not unicode: |
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50 | # src = src.decode(encoding) |
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51 | ## end of Terrel's patch |
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52 | |
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53 | self._src = src |
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54 | self._filename = filename |
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55 | |
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56 | self._srcLen = len(src) |
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57 | if breakPoint == None: |
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58 | self._breakPoint = self._srcLen |
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59 | else: |
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60 | self.setBreakPoint(breakPoint) |
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61 | self._pos = 0 |
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62 | self._bookmarks = {} |
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63 | self._posTobookmarkMap = {} |
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64 | |
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65 | ## collect some meta-information |
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66 | self._EOLs = [] |
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67 | pos = 0 |
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68 | while pos < len(self): |
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69 | EOLmatch = EOLZre.search(src, pos) |
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70 | self._EOLs.append(EOLmatch.start()) |
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71 | pos = EOLmatch.end() |
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72 | |
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73 | self._BOLs = [] |
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74 | for pos in self._EOLs: |
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75 | BOLpos = self.findBOL(pos) |
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76 | self._BOLs.append(BOLpos) |
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77 | |
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78 | def src(self): |
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79 | return self._src |
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80 | |
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81 | def filename(self): |
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82 | return self._filename |
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83 | |
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84 | def __len__(self): |
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85 | return self._breakPoint |
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86 | |
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87 | def __getitem__(self, i): |
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88 | self.checkPos(i) |
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89 | return self._src[i] |
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90 | |
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91 | def __getslice__(self, i, j): |
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92 | i = max(i, 0); j = max(j, 0) |
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93 | return self._src[i:j] |
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94 | |
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95 | def splitlines(self): |
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96 | if not hasattr(self, '_srcLines'): |
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97 | self._srcLines = self._src.splitlines() |
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98 | return self._srcLines |
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99 | |
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100 | def lineNum(self, pos=None): |
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101 | if pos == None: |
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102 | pos = self._pos |
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103 | |
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104 | for i in range(len(self._BOLs)): |
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105 | if pos >= self._BOLs[i] and pos <= self._EOLs[i]: |
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106 | return i |
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107 | |
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108 | def getRowCol(self, pos=None): |
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109 | if pos == None: |
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110 | pos = self._pos |
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111 | lineNum = self.lineNum(pos) |
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112 | BOL, EOL = self._BOLs[lineNum], self._EOLs[lineNum] |
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113 | return lineNum+1, pos-BOL+1 |
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114 | |
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115 | def getRowColLine(self, pos=None): |
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116 | if pos == None: |
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117 | pos = self._pos |
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118 | row, col = self.getRowCol(pos) |
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119 | return row, col, self.splitlines()[row-1] |
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120 | |
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121 | def getLine(self, pos): |
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122 | if pos == None: |
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123 | pos = self._pos |
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124 | lineNum = self.lineNum(pos) |
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125 | return self.splitlines()[lineNum] |
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126 | |
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127 | def pos(self): |
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128 | return self._pos |
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129 | |
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130 | def setPos(self, pos): |
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131 | self.checkPos(pos) |
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132 | self._pos = pos |
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133 | |
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134 | |
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135 | def validPos(self, pos): |
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136 | return pos <= self._breakPoint and pos >=0 |
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137 | |
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138 | def checkPos(self, pos): |
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139 | if not pos <= self._breakPoint: |
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140 | raise Error("pos (" + str(pos) + ") is invalid: beyond the stream's end (" + |
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141 | str(self._breakPoint-1) + ")" ) |
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142 | elif not pos >=0: |
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143 | raise Error("pos (" + str(pos) + ") is invalid: less than 0" ) |
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144 | |
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145 | def breakPoint(self): |
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146 | return self._breakPoint |
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147 | |
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148 | def setBreakPoint(self, pos): |
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149 | if pos > self._srcLen: |
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150 | raise Error("New breakpoint (" + str(pos) + |
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151 | ") is invalid: beyond the end of stream's source string (" + |
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152 | str(self._srcLen) + ")" ) |
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153 | elif not pos >= 0: |
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154 | raise Error("New breakpoint (" + str(pos) + ") is invalid: less than 0" ) |
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155 | |
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156 | self._breakPoint = pos |
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157 | |
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158 | def setBookmark(self, name): |
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159 | self._bookmarks[name] = self._pos |
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160 | self._posTobookmarkMap[self._pos] = name |
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161 | |
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162 | def hasBookmark(self, name): |
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163 | return self._bookmarks.has_key(name) |
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164 | |
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165 | def gotoBookmark(self, name): |
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166 | if not self.hasBookmark(name): |
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167 | raise Error("Invalid bookmark (" + name + ") is invalid: does not exist") |
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168 | pos = self._bookmarks[name] |
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169 | if not self.validPos(pos): |
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170 | raise Error("Invalid bookmark (" + name + ', '+ |
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171 | str(pos) + ") is invalid: pos is out of range" ) |
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172 | self._pos = pos |
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173 | |
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174 | def atEnd(self): |
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175 | return self._pos >= self._breakPoint |
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176 | |
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177 | def atStart(self): |
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178 | return self._pos == 0 |
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179 | |
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180 | def peek(self, offset=0): |
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181 | self.checkPos(self._pos+offset) |
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182 | pos = self._pos + offset |
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183 | return self._src[pos] |
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184 | |
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185 | def getc(self): |
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186 | pos = self._pos |
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187 | if self.validPos(pos+1): |
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188 | self._pos += 1 |
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189 | return self._src[pos] |
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190 | |
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191 | def ungetc(self, c=None): |
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192 | if not self.atStart(): |
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193 | raise Error('Already at beginning of stream') |
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194 | |
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195 | self._pos -= 1 |
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196 | if not c==None: |
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197 | self._src[self._pos] = c |
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198 | |
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199 | def advance(self, offset=1): |
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200 | self.checkPos(self._pos + offset) |
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201 | self._pos += offset |
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202 | |
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203 | def rev(self, offset=1): |
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204 | self.checkPos(self._pos - offset) |
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205 | self._pos -= offset |
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206 | |
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207 | def read(self, offset): |
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208 | self.checkPos(self._pos + offset) |
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209 | start = self._pos |
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210 | self._pos += offset |
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211 | return self._src[start:self._pos] |
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212 | |
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213 | def readTo(self, to, start=None): |
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214 | self.checkPos(to) |
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215 | if start == None: |
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216 | start = self._pos |
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217 | self._pos = to |
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218 | return self._src[start:to] |
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219 | |
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220 | |
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221 | def readToEOL(self, start=None, gobble=True): |
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222 | EOLmatch = EOLZre.search(self.src(), self.pos()) |
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223 | if gobble: |
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224 | pos = EOLmatch.end() |
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225 | else: |
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226 | pos = EOLmatch.start() |
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227 | return self.readTo(to=pos, start=start) |
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228 | |
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229 | |
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230 | def find(self, it, pos=None): |
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231 | if pos == None: |
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232 | pos = self._pos |
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233 | return self._src.find(it, pos ) |
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234 | |
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235 | def startswith(self, it, pos=None): |
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236 | if self.find(it, pos) == self.pos(): |
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237 | return True |
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238 | else: |
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239 | return False |
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240 | |
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241 | def rfind(self, it, pos): |
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242 | if pos == None: |
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243 | pos = self._pos |
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244 | return self._src.rfind(it, pos) |
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245 | |
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246 | def findBOL(self, pos=None): |
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247 | if pos == None: |
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248 | pos = self._pos |
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249 | src = self.src() |
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250 | return max(src.rfind('\n',0,pos)+1, src.rfind('\r',0,pos)+1, 0) |
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251 | |
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252 | def findEOL(self, pos=None, gobble=False): |
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253 | if pos == None: |
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254 | pos = self._pos |
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255 | |
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256 | match = EOLZre.search(self.src(), pos) |
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257 | if gobble: |
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258 | return match.end() |
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259 | else: |
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260 | return match.start() |
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261 | |
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262 | def isLineClearToPos(self, pos=None): |
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263 | if pos == None: |
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264 | pos = self.pos() |
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265 | self.checkPos(pos) |
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266 | src = self.src() |
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267 | BOL = self.findBOL() |
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268 | return BOL == pos or src[BOL:pos].isspace() |
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269 | |
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270 | def matches(self, strOrRE): |
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271 | if isinstance(strOrRE, (str, unicode)): |
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272 | return self.startswith(strOrRE, pos=self.pos()) |
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273 | else: # assume an re object |
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274 | return strOrRE.match(self.src(), self.pos()) |
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275 | |
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276 | def matchWhiteSpace(self, WSchars=' \f\t'): |
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277 | return (not self.atEnd()) and self.peek() in WSchars |
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278 | |
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279 | def getWhiteSpace(self, max=None, WSchars=' \f\t'): |
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280 | if not self.matchWhiteSpace(WSchars): |
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281 | return '' |
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282 | start = self.pos() |
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283 | breakPoint = self.breakPoint() |
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284 | if max is not None: |
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285 | breakPoint = min(breakPoint, self.pos()+max) |
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286 | while self.pos() < breakPoint: |
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287 | self.advance() |
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288 | if not self.matchWhiteSpace(WSchars): |
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289 | break |
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290 | return self.src()[start:self.pos()] |
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291 | |
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292 | def matchNonWhiteSpace(self, WSchars=' \f\t\n\r'): |
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293 | return self.atEnd() or not self.peek() in WSchars |
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294 | |
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295 | def getNonWhiteSpace(self, WSchars=' \f\t\n\r'): |
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296 | if not self.matchNonWhiteSpace(WSchars): |
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297 | return '' |
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298 | start = self.pos() |
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299 | while self.pos() < self.breakPoint(): |
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300 | self.advance() |
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301 | if not self.matchNonWhiteSpace(WSchars): |
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302 | break |
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303 | return self.src()[start:self.pos()] |
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