1 | "Usage: unparse.py <path to source file>"
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2 | import sys
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3 | import _ast
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4 | import cStringIO
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5 | import os
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6 |
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7 | def interleave(inter, f, seq):
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8 | """Call f on each item in seq, calling inter() in between.
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9 | """
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10 | seq = iter(seq)
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11 | try:
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12 | f(seq.next())
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13 | except StopIteration:
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14 | pass
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15 | else:
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16 | for x in seq:
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17 | inter()
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18 | f(x)
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19 |
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20 | class Unparser:
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21 | """Methods in this class recursively traverse an AST and
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22 | output source code for the abstract syntax; original formatting
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23 | is disregarged. """
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24 |
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25 | def __init__(self, tree, file = sys.stdout):
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26 | """Unparser(tree, file=sys.stdout) -> None.
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27 | Print the source for tree to file."""
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28 | self.f = file
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29 | self._indent = 0
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30 | self.dispatch(tree)
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31 | print >>self.f,""
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32 | self.f.flush()
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33 |
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34 | def fill(self, text = ""):
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35 | "Indent a piece of text, according to the current indentation level"
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36 | self.f.write("\n"+" "*self._indent + text)
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37 |
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38 | def write(self, text):
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39 | "Append a piece of text to the current line."
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40 | self.f.write(text)
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41 |
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42 | def enter(self):
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43 | "Print ':', and increase the indentation."
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44 | self.write(":")
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45 | self._indent += 1
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46 |
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47 | def leave(self):
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48 | "Decrease the indentation level."
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49 | self._indent -= 1
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50 |
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51 | def dispatch(self, tree):
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52 | "Dispatcher function, dispatching tree type T to method _T."
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53 | if isinstance(tree, list):
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54 | for t in tree:
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55 | self.dispatch(t)
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56 | return
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57 | meth = getattr(self, "_"+tree.__class__.__name__)
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58 | meth(tree)
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59 |
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60 |
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61 | ############### Unparsing methods ######################
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62 | # There should be one method per concrete grammar type #
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63 | # Constructors should be grouped by sum type. Ideally, #
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64 | # this would follow the order in the grammar, but #
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65 | # currently doesn't. #
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66 | ########################################################
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67 |
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68 | def _Module(self, tree):
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69 | for stmt in tree.body:
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70 | self.dispatch(stmt)
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71 |
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72 | # stmt
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73 | def _Expr(self, tree):
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74 | self.fill()
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75 | self.dispatch(tree.value)
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76 |
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77 | def _Import(self, t):
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78 | self.fill("import ")
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79 | interleave(lambda: self.write(", "), self.dispatch, t.names)
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80 |
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81 | def _ImportFrom(self, t):
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82 | self.fill("from ")
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83 | self.write(t.module)
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84 | self.write(" import ")
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85 | interleave(lambda: self.write(", "), self.dispatch, t.names)
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86 | # XXX(jpe) what is level for?
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87 |
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88 | def _Assign(self, t):
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89 | self.fill()
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90 | for target in t.targets:
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91 | self.dispatch(target)
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92 | self.write(" = ")
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93 | self.dispatch(t.value)
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94 |
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95 | def _AugAssign(self, t):
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96 | self.fill()
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97 | self.dispatch(t.target)
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98 | self.write(" "+self.binop[t.op.__class__.__name__]+"= ")
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99 | self.dispatch(t.value)
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100 |
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101 | def _Return(self, t):
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102 | self.fill("return")
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103 | if t.value:
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104 | self.write(" ")
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105 | self.dispatch(t.value)
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106 |
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107 | def _Pass(self, t):
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108 | self.fill("pass")
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109 |
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110 | def _Break(self, t):
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111 | self.fill("break")
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112 |
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113 | def _Continue(self, t):
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114 | self.fill("continue")
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115 |
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116 | def _Delete(self, t):
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117 | self.fill("del ")
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118 | self.dispatch(t.targets)
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119 |
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120 | def _Assert(self, t):
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121 | self.fill("assert ")
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122 | self.dispatch(t.test)
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123 | if t.msg:
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124 | self.write(", ")
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125 | self.dispatch(t.msg)
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126 |
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127 | def _Exec(self, t):
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128 | self.fill("exec ")
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129 | self.dispatch(t.body)
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130 | if t.globals:
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131 | self.write(" in ")
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132 | self.dispatch(t.globals)
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133 | if t.locals:
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134 | self.write(", ")
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135 | self.dispatch(t.locals)
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136 |
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137 | def _Print(self, t):
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138 | self.fill("print ")
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139 | do_comma = False
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140 | if t.dest:
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141 | self.write(">>")
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142 | self.dispatch(t.dest)
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143 | do_comma = True
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144 | for e in t.values:
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145 | if do_comma:self.write(", ")
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146 | else:do_comma=True
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147 | self.dispatch(e)
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148 | if not t.nl:
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149 | self.write(",")
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150 |
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151 | def _Global(self, t):
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152 | self.fill("global ")
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153 | interleave(lambda: self.write(", "), self.write, t.names)
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154 |
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155 | def _Yield(self, t):
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156 | self.write("(")
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157 | self.write("yield")
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158 | if t.value:
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159 | self.write(" ")
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160 | self.dispatch(t.value)
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161 | self.write(")")
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162 |
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163 | def _Raise(self, t):
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164 | self.fill('raise ')
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165 | if t.type:
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166 | self.dispatch(t.type)
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167 | if t.inst:
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168 | self.write(", ")
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169 | self.dispatch(t.inst)
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170 | if t.tback:
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171 | self.write(", ")
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172 | self.dispatch(t.tback)
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173 |
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174 | def _TryExcept(self, t):
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175 | self.fill("try")
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176 | self.enter()
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177 | self.dispatch(t.body)
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178 | self.leave()
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179 |
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180 | for ex in t.handlers:
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181 | self.dispatch(ex)
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182 | if t.orelse:
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183 | self.fill("else")
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184 | self.enter()
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185 | self.dispatch(t.orelse)
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186 | self.leave()
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187 |
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188 | def _TryFinally(self, t):
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189 | self.fill("try")
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190 | self.enter()
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191 | self.dispatch(t.body)
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192 | self.leave()
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193 |
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194 | self.fill("finally")
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195 | self.enter()
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196 | self.dispatch(t.finalbody)
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197 | self.leave()
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198 |
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199 | def _ExceptHandler(self, t):
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200 | self.fill("except")
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201 | if t.type:
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202 | self.write(" ")
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203 | self.dispatch(t.type)
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204 | if t.name:
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205 | self.write(", ")
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206 | self.dispatch(t.name)
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207 | self.enter()
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208 | self.dispatch(t.body)
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209 | self.leave()
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210 |
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211 | def _ClassDef(self, t):
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212 | self.write("\n")
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213 | self.fill("class "+t.name)
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214 | if t.bases:
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215 | self.write("(")
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216 | for a in t.bases:
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217 | self.dispatch(a)
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218 | self.write(", ")
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219 | self.write(")")
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220 | self.enter()
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221 | self.dispatch(t.body)
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222 | self.leave()
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223 |
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224 | def _FunctionDef(self, t):
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225 | self.write("\n")
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226 | for deco in t.decorator_list:
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227 | self.fill("@")
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228 | self.dispatch(deco)
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229 | self.fill("def "+t.name + "(")
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230 | self.dispatch(t.args)
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231 | self.write(")")
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232 | self.enter()
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233 | self.dispatch(t.body)
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234 | self.leave()
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235 |
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236 | def _For(self, t):
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237 | self.fill("for ")
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238 | self.dispatch(t.target)
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239 | self.write(" in ")
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240 | self.dispatch(t.iter)
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241 | self.enter()
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242 | self.dispatch(t.body)
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243 | self.leave()
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244 | if t.orelse:
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245 | self.fill("else")
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246 | self.enter()
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247 | self.dispatch(t.orelse)
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248 | self.leave
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249 |
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250 | def _If(self, t):
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251 | self.fill("if ")
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252 | self.dispatch(t.test)
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253 | self.enter()
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254 | # XXX elif?
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255 | self.dispatch(t.body)
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256 | self.leave()
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257 | if t.orelse:
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258 | self.fill("else")
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259 | self.enter()
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260 | self.dispatch(t.orelse)
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261 | self.leave()
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262 |
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263 | def _While(self, t):
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264 | self.fill("while ")
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265 | self.dispatch(t.test)
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266 | self.enter()
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267 | self.dispatch(t.body)
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268 | self.leave()
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269 | if t.orelse:
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270 | self.fill("else")
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271 | self.enter()
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272 | self.dispatch(t.orelse)
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273 | self.leave
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274 |
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275 | def _With(self, t):
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276 | self.fill("with ")
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277 | self.dispatch(t.context_expr)
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278 | if t.optional_vars:
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279 | self.write(" as ")
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280 | self.dispatch(t.optional_vars)
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281 | self.enter()
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282 | self.dispatch(t.body)
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283 | self.leave()
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284 |
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285 | # expr
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286 | def _Str(self, tree):
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287 | self.write(repr(tree.s))
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288 |
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289 | def _Name(self, t):
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290 | self.write(t.id)
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291 |
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292 | def _Repr(self, t):
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293 | self.write("`")
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294 | self.dispatch(t.value)
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295 | self.write("`")
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296 |
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297 | def _Num(self, t):
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298 | self.write(repr(t.n))
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299 |
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300 | def _List(self, t):
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301 | self.write("[")
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302 | interleave(lambda: self.write(", "), self.dispatch, t.elts)
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303 | self.write("]")
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304 |
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305 | def _ListComp(self, t):
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306 | self.write("[")
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307 | self.dispatch(t.elt)
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308 | for gen in t.generators:
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309 | self.dispatch(gen)
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310 | self.write("]")
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311 |
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312 | def _GeneratorExp(self, t):
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313 | self.write("(")
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314 | self.dispatch(t.elt)
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315 | for gen in t.generators:
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316 | self.dispatch(gen)
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317 | self.write(")")
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318 |
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319 | def _comprehension(self, t):
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320 | self.write(" for ")
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321 | self.dispatch(t.target)
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322 | self.write(" in ")
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323 | self.dispatch(t.iter)
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324 | for if_clause in t.ifs:
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325 | self.write(" if ")
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326 | self.dispatch(if_clause)
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327 |
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328 | def _IfExp(self, t):
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329 | self.write("(")
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330 | self.dispatch(t.body)
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331 | self.write(" if ")
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332 | self.dispatch(t.test)
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333 | self.write(" else ")
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334 | self.dispatch(t.orelse)
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335 | self.write(")")
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336 |
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337 | def _Dict(self, t):
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338 | self.write("{")
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339 | def writem((k, v)):
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340 | self.dispatch(k)
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341 | self.write(": ")
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342 | self.dispatch(v)
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343 | interleave(lambda: self.write(", "), writem, zip(t.keys, t.values))
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344 | self.write("}")
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345 |
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346 | def _Tuple(self, t):
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347 | self.write("(")
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348 | if len(t.elts) == 1:
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349 | (elt,) = t.elts
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350 | self.dispatch(elt)
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351 | self.write(",")
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352 | else:
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353 | interleave(lambda: self.write(", "), self.dispatch, t.elts)
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354 | self.write(")")
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355 |
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356 | unop = {"Invert":"~", "Not": "not", "UAdd":"+", "USub":"-"}
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357 | def _UnaryOp(self, t):
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358 | self.write(self.unop[t.op.__class__.__name__])
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359 | self.write("(")
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360 | self.dispatch(t.operand)
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361 | self.write(")")
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362 |
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363 | binop = { "Add":"+", "Sub":"-", "Mult":"*", "Div":"/", "Mod":"%",
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364 | "LShift":">>", "RShift":"<<", "BitOr":"|", "BitXor":"^", "BitAnd":"&",
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365 | "FloorDiv":"//", "Pow": "**"}
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366 | def _BinOp(self, t):
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367 | self.write("(")
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368 | self.dispatch(t.left)
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369 | self.write(" " + self.binop[t.op.__class__.__name__] + " ")
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370 | self.dispatch(t.right)
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371 | self.write(")")
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372 |
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373 | cmpops = {"Eq":"==", "NotEq":"!=", "Lt":"<", "LtE":"<=", "Gt":">", "GtE":">=",
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374 | "Is":"is", "IsNot":"is not", "In":"in", "NotIn":"not in"}
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375 | def _Compare(self, t):
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376 | self.write("(")
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377 | self.dispatch(t.left)
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378 | for o, e in zip(t.ops, t.comparators):
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379 | self.write(" " + self.cmpops[o.__class__.__name__] + " ")
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380 | self.dispatch(e)
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381 | self.write(")")
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382 |
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383 | boolops = {_ast.And: 'and', _ast.Or: 'or'}
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384 | def _BoolOp(self, t):
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385 | self.write("(")
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386 | s = " %s " % self.boolops[t.op.__class__]
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387 | interleave(lambda: self.write(s), self.dispatch, t.values)
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388 | self.write(")")
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389 |
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390 | def _Attribute(self,t):
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391 | self.dispatch(t.value)
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392 | self.write(".")
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393 | self.write(t.attr)
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394 |
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395 | def _Call(self, t):
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396 | self.dispatch(t.func)
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397 | self.write("(")
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398 | comma = False
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399 | for e in t.args:
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400 | if comma: self.write(", ")
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401 | else: comma = True
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402 | self.dispatch(e)
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403 | for e in t.keywords:
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404 | if comma: self.write(", ")
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405 | else: comma = True
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406 | self.dispatch(e)
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407 | if t.starargs:
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408 | if comma: self.write(", ")
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409 | else: comma = True
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410 | self.write("*")
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411 | self.dispatch(t.starargs)
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412 | if t.kwargs:
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413 | if comma: self.write(", ")
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414 | else: comma = True
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415 | self.write("**")
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416 | self.dispatch(t.kwargs)
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417 | self.write(")")
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418 |
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419 | def _Subscript(self, t):
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420 | self.dispatch(t.value)
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421 | self.write("[")
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422 | self.dispatch(t.slice)
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423 | self.write("]")
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424 |
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425 | # slice
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426 | def _Ellipsis(self, t):
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427 | self.write("...")
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428 |
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429 | def _Index(self, t):
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430 | self.dispatch(t.value)
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431 |
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432 | def _Slice(self, t):
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433 | if t.lower:
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434 | self.dispatch(t.lower)
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435 | self.write(":")
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436 | if t.upper:
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437 | self.dispatch(t.upper)
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438 | if t.step:
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439 | self.write(":")
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440 | self.dispatch(t.step)
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441 |
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442 | def _ExtSlice(self, t):
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443 | interleave(lambda: self.write(', '), self.dispatch, t.dims)
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444 |
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445 | # others
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446 | def _arguments(self, t):
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447 | first = True
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448 | nonDef = len(t.args)-len(t.defaults)
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449 | for a in t.args[0:nonDef]:
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450 | if first:first = False
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451 | else: self.write(", ")
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452 | self.dispatch(a)
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453 | for a,d in zip(t.args[nonDef:], t.defaults):
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454 | if first:first = False
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455 | else: self.write(", ")
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456 | self.dispatch(a),
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457 | self.write("=")
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458 | self.dispatch(d)
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459 | if t.vararg:
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460 | if first:first = False
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461 | else: self.write(", ")
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462 | self.write("*"+t.vararg)
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463 | if t.kwarg:
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464 | if first:first = False
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465 | else: self.write(", ")
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466 | self.write("**"+t.kwarg)
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467 |
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468 | def _keyword(self, t):
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469 | self.write(t.arg)
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470 | self.write("=")
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471 | self.dispatch(t.value)
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472 |
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473 | def _Lambda(self, t):
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474 | self.write("lambda ")
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475 | self.dispatch(t.args)
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476 | self.write(": ")
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477 | self.dispatch(t.body)
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478 |
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479 | def _alias(self, t):
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480 | self.write(t.name)
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481 | if t.asname:
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482 | self.write(" as "+t.asname)
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483 |
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484 | def roundtrip(filename, output=sys.stdout):
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485 | source = open(filename).read()
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486 | tree = compile(source, filename, "exec", _ast.PyCF_ONLY_AST)
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487 | Unparser(tree, output)
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488 |
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489 |
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490 |
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491 | def testdir(a):
|
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492 | try:
|
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493 | names = [n for n in os.listdir(a) if n.endswith('.py')]
|
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494 | except OSError:
|
---|
495 | print >> sys.stderr, "Directory not readable: %s" % a
|
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496 | else:
|
---|
497 | for n in names:
|
---|
498 | fullname = os.path.join(a, n)
|
---|
499 | if os.path.isfile(fullname):
|
---|
500 | output = cStringIO.StringIO()
|
---|
501 | print 'Testing %s' % fullname
|
---|
502 | try:
|
---|
503 | roundtrip(fullname, output)
|
---|
504 | except Exception, e:
|
---|
505 | print ' Failed to compile, exception is %s' % repr(e)
|
---|
506 | elif os.path.isdir(fullname):
|
---|
507 | testdir(fullname)
|
---|
508 |
|
---|
509 | def main(args):
|
---|
510 | if args[0] == '--testdir':
|
---|
511 | for a in args[1:]:
|
---|
512 | testdir(a)
|
---|
513 | else:
|
---|
514 | for a in args:
|
---|
515 | roundtrip(a)
|
---|
516 |
|
---|
517 | if __name__=='__main__':
|
---|
518 | main(sys.argv[1:])
|
---|