| 1 | # ast.py |
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| 2 | # Copyright (C) Mako developers |
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| 3 | # |
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| 4 | # This module is part of Mako and is released under |
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| 5 | # the MIT License: http://www.opensource.org/licenses/mit-license.php |
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| 6 | |
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| 7 | """Handles parsing of Python code. |
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| 8 | |
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| 9 | Parsing to AST is done via _ast on Python > 2.5, otherwise the compiler |
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| 10 | module is used. |
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| 11 | """ |
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| 12 | |
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| 13 | from StringIO import StringIO |
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| 14 | from mako import exceptions, util |
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| 15 | |
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| 16 | # words that cannot be assigned to (notably smaller than the total keys in __builtins__) |
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| 17 | reserved = util.Set(['True', 'False', 'None']) |
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| 18 | |
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| 19 | try: |
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| 20 | import _ast |
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| 21 | util.restore__ast(_ast) |
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| 22 | import _ast_util |
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| 23 | except ImportError: |
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| 24 | _ast = None |
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| 25 | from compiler import parse as compiler_parse |
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| 26 | from compiler import visitor |
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| 27 | |
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| 28 | |
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| 29 | def parse(code, mode='exec', **exception_kwargs): |
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| 30 | """Parse an expression into AST""" |
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| 31 | try: |
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| 32 | if _ast: |
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| 33 | return _ast_util.parse(code, '<unknown>', mode) |
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| 34 | else: |
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| 35 | return compiler_parse(code, mode) |
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| 36 | except Exception, e: |
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| 37 | raise exceptions.SyntaxException("(%s) %s (%s)" % (e.__class__.__name__, str(e), repr(code[0:50])), **exception_kwargs) |
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| 38 | |
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| 39 | |
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| 40 | if _ast: |
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| 41 | class FindIdentifiers(_ast_util.NodeVisitor): |
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| 42 | def __init__(self, listener, **exception_kwargs): |
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| 43 | self.in_function = False |
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| 44 | self.in_assign_targets = False |
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| 45 | self.local_ident_stack = {} |
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| 46 | self.listener = listener |
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| 47 | self.exception_kwargs = exception_kwargs |
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| 48 | def _add_declared(self, name): |
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| 49 | if not self.in_function: |
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| 50 | self.listener.declared_identifiers.add(name) |
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| 51 | def visit_ClassDef(self, node): |
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| 52 | self._add_declared(node.name) |
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| 53 | def visit_Assign(self, node): |
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| 54 | # flip around the visiting of Assign so the expression gets evaluated first, |
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| 55 | # in the case of a clause like "x=x+5" (x is undeclared) |
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| 56 | self.visit(node.value) |
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| 57 | in_a = self.in_assign_targets |
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| 58 | self.in_assign_targets = True |
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| 59 | for n in node.targets: |
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| 60 | self.visit(n) |
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| 61 | self.in_assign_targets = in_a |
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| 62 | def visit_FunctionDef(self, node): |
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| 63 | self._add_declared(node.name) |
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| 64 | # push function state onto stack. dont log any |
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| 65 | # more identifiers as "declared" until outside of the function, |
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| 66 | # but keep logging identifiers as "undeclared". |
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| 67 | # track argument names in each function header so they arent counted as "undeclared" |
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| 68 | saved = {} |
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| 69 | inf = self.in_function |
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| 70 | self.in_function = True |
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| 71 | for arg in node.args.args: |
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| 72 | if arg.id in self.local_ident_stack: |
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| 73 | saved[arg.id] = True |
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| 74 | else: |
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| 75 | self.local_ident_stack[arg.id] = True |
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| 76 | for n in node.body: |
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| 77 | self.visit(n) |
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| 78 | self.in_function = inf |
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| 79 | for arg in node.args.args: |
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| 80 | if arg.id not in saved: |
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| 81 | del self.local_ident_stack[arg.id] |
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| 82 | def visit_For(self, node): |
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| 83 | # flip around visit |
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| 84 | self.visit(node.iter) |
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| 85 | self.visit(node.target) |
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| 86 | for statement in node.body: |
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| 87 | self.visit(statement) |
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| 88 | for statement in node.orelse: |
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| 89 | self.visit(statement) |
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| 90 | def visit_Name(self, node): |
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| 91 | if isinstance(node.ctx, _ast.Store): |
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| 92 | self._add_declared(node.id) |
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| 93 | if node.id not in reserved and node.id not in self.listener.declared_identifiers and node.id not in self.local_ident_stack: |
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| 94 | self.listener.undeclared_identifiers.add(node.id) |
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| 95 | def visit_Import(self, node): |
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| 96 | for name in node.names: |
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| 97 | if name.asname is not None: |
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| 98 | self._add_declared(name.asname) |
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| 99 | else: |
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| 100 | self._add_declared(name.name.split('.')[0]) |
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| 101 | def visit_ImportFrom(self, node): |
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| 102 | for name in node.names: |
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| 103 | if name.asname is not None: |
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| 104 | self._add_declared(name.asname) |
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| 105 | else: |
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| 106 | if name.name == '*': |
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| 107 | raise exceptions.CompileException("'import *' is not supported, since all identifier names must be explicitly declared. Please use the form 'from <modulename> import <name1>, <name2>, ...' instead.", **self.exception_kwargs) |
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| 108 | self._add_declared(name.name) |
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| 109 | |
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| 110 | class FindTuple(_ast_util.NodeVisitor): |
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| 111 | def __init__(self, listener, code_factory, **exception_kwargs): |
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| 112 | self.listener = listener |
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| 113 | self.exception_kwargs = exception_kwargs |
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| 114 | self.code_factory = code_factory |
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| 115 | def visit_Tuple(self, node): |
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| 116 | for n in node.elts: |
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| 117 | p = self.code_factory(n, **self.exception_kwargs) |
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| 118 | self.listener.codeargs.append(p) |
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| 119 | self.listener.args.append(ExpressionGenerator(n).value()) |
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| 120 | self.listener.declared_identifiers = self.listener.declared_identifiers.union(p.declared_identifiers) |
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| 121 | self.listener.undeclared_identifiers = self.listener.undeclared_identifiers.union(p.undeclared_identifiers) |
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| 122 | |
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| 123 | class ParseFunc(_ast_util.NodeVisitor): |
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| 124 | def __init__(self, listener, **exception_kwargs): |
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| 125 | self.listener = listener |
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| 126 | self.exception_kwargs = exception_kwargs |
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| 127 | def visit_FunctionDef(self, node): |
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| 128 | self.listener.funcname = node.name |
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| 129 | argnames = [arg.id for arg in node.args.args] |
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| 130 | if node.args.vararg: |
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| 131 | argnames.append(node.args.vararg) |
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| 132 | if node.args.kwarg: |
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| 133 | argnames.append(node.args.kwarg) |
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| 134 | self.listener.argnames = argnames |
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| 135 | self.listener.defaults = node.args.defaults # ast |
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| 136 | self.listener.varargs = node.args.vararg |
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| 137 | self.listener.kwargs = node.args.kwarg |
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| 138 | |
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| 139 | class ExpressionGenerator(object): |
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| 140 | def __init__(self, astnode): |
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| 141 | self.generator = _ast_util.SourceGenerator(' ' * 4) |
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| 142 | self.generator.visit(astnode) |
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| 143 | def value(self): |
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| 144 | return ''.join(self.generator.result) |
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| 145 | else: |
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| 146 | class FindIdentifiers(object): |
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| 147 | def __init__(self, listener, **exception_kwargs): |
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| 148 | self.in_function = False |
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| 149 | self.local_ident_stack = {} |
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| 150 | self.listener = listener |
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| 151 | self.exception_kwargs = exception_kwargs |
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| 152 | def _add_declared(self, name): |
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| 153 | if not self.in_function: |
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| 154 | self.listener.declared_identifiers.add(name) |
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| 155 | def visitClass(self, node, *args): |
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| 156 | self._add_declared(node.name) |
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| 157 | def visitAssName(self, node, *args): |
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| 158 | self._add_declared(node.name) |
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| 159 | def visitAssign(self, node, *args): |
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| 160 | # flip around the visiting of Assign so the expression gets evaluated first, |
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| 161 | # in the case of a clause like "x=x+5" (x is undeclared) |
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| 162 | self.visit(node.expr, *args) |
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| 163 | for n in node.nodes: |
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| 164 | self.visit(n, *args) |
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| 165 | def visitFunction(self,node, *args): |
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| 166 | self._add_declared(node.name) |
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| 167 | # push function state onto stack. dont log any |
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| 168 | # more identifiers as "declared" until outside of the function, |
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| 169 | # but keep logging identifiers as "undeclared". |
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| 170 | # track argument names in each function header so they arent counted as "undeclared" |
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| 171 | saved = {} |
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| 172 | inf = self.in_function |
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| 173 | self.in_function = True |
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| 174 | for arg in node.argnames: |
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| 175 | if arg in self.local_ident_stack: |
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| 176 | saved[arg] = True |
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| 177 | else: |
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| 178 | self.local_ident_stack[arg] = True |
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| 179 | for n in node.getChildNodes(): |
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| 180 | self.visit(n, *args) |
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| 181 | self.in_function = inf |
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| 182 | for arg in node.argnames: |
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| 183 | if arg not in saved: |
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| 184 | del self.local_ident_stack[arg] |
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| 185 | def visitFor(self, node, *args): |
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| 186 | # flip around visit |
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| 187 | self.visit(node.list, *args) |
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| 188 | self.visit(node.assign, *args) |
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| 189 | self.visit(node.body, *args) |
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| 190 | def visitName(self, node, *args): |
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| 191 | if node.name not in reserved and node.name not in self.listener.declared_identifiers and node.name not in self.local_ident_stack: |
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| 192 | self.listener.undeclared_identifiers.add(node.name) |
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| 193 | def visitImport(self, node, *args): |
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| 194 | for (mod, alias) in node.names: |
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| 195 | if alias is not None: |
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| 196 | self._add_declared(alias) |
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| 197 | else: |
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| 198 | self._add_declared(mod.split('.')[0]) |
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| 199 | def visitFrom(self, node, *args): |
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| 200 | for (mod, alias) in node.names: |
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| 201 | if alias is not None: |
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| 202 | self._add_declared(alias) |
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| 203 | else: |
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| 204 | if mod == '*': |
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| 205 | raise exceptions.CompileException("'import *' is not supported, since all identifier names must be explicitly declared. Please use the form 'from <modulename> import <name1>, <name2>, ...' instead.", **self.exception_kwargs) |
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| 206 | self._add_declared(mod) |
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| 207 | def visit(self, expr): |
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| 208 | visitor.walk(expr, self) #, walker=walker()) |
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| 209 | |
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| 210 | class FindTuple(object): |
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| 211 | def __init__(self, listener, code_factory, **exception_kwargs): |
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| 212 | self.listener = listener |
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| 213 | self.exception_kwargs = exception_kwargs |
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| 214 | self.code_factory = code_factory |
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| 215 | def visitTuple(self, node, *args): |
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| 216 | for n in node.nodes: |
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| 217 | p = self.code_factory(n, **self.exception_kwargs) |
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| 218 | self.listener.codeargs.append(p) |
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| 219 | self.listener.args.append(ExpressionGenerator(n).value()) |
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| 220 | self.listener.declared_identifiers = self.listener.declared_identifiers.union(p.declared_identifiers) |
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| 221 | self.listener.undeclared_identifiers = self.listener.undeclared_identifiers.union(p.undeclared_identifiers) |
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| 222 | def visit(self, expr): |
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| 223 | visitor.walk(expr, self) #, walker=walker()) |
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| 224 | |
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| 225 | class ParseFunc(object): |
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| 226 | def __init__(self, listener, **exception_kwargs): |
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| 227 | self.listener = listener |
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| 228 | self.exception_kwargs = exception_kwargs |
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| 229 | def visitFunction(self, node, *args): |
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| 230 | self.listener.funcname = node.name |
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| 231 | self.listener.argnames = node.argnames |
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| 232 | self.listener.defaults = node.defaults |
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| 233 | self.listener.varargs = node.varargs |
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| 234 | self.listener.kwargs = node.kwargs |
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| 235 | def visit(self, expr): |
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| 236 | visitor.walk(expr, self) |
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| 237 | |
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| 238 | class ExpressionGenerator(object): |
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| 239 | """given an AST node, generates an equivalent literal Python expression.""" |
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| 240 | def __init__(self, astnode): |
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| 241 | self.buf = StringIO() |
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| 242 | visitor.walk(astnode, self) #, walker=walker()) |
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| 243 | def value(self): |
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| 244 | return self.buf.getvalue() |
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| 245 | def operator(self, op, node, *args): |
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| 246 | self.buf.write("(") |
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| 247 | self.visit(node.left, *args) |
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| 248 | self.buf.write(" %s " % op) |
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| 249 | self.visit(node.right, *args) |
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| 250 | self.buf.write(")") |
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| 251 | def booleanop(self, op, node, *args): |
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| 252 | self.visit(node.nodes[0]) |
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| 253 | for n in node.nodes[1:]: |
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| 254 | self.buf.write(" " + op + " ") |
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| 255 | self.visit(n, *args) |
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| 256 | def visitConst(self, node, *args): |
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| 257 | self.buf.write(repr(node.value)) |
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| 258 | def visitAssName(self, node, *args): |
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| 259 | # TODO: figure out OP_ASSIGN, other OP_s |
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| 260 | self.buf.write(node.name) |
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| 261 | def visitName(self, node, *args): |
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| 262 | self.buf.write(node.name) |
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| 263 | def visitMul(self, node, *args): |
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| 264 | self.operator("*", node, *args) |
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| 265 | def visitAnd(self, node, *args): |
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| 266 | self.booleanop("and", node, *args) |
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| 267 | def visitOr(self, node, *args): |
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| 268 | self.booleanop("or", node, *args) |
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| 269 | def visitBitand(self, node, *args): |
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| 270 | self.booleanop("&", node, *args) |
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| 271 | def visitBitor(self, node, *args): |
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| 272 | self.booleanop("|", node, *args) |
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| 273 | def visitBitxor(self, node, *args): |
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| 274 | self.booleanop("^", node, *args) |
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| 275 | def visitAdd(self, node, *args): |
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| 276 | self.operator("+", node, *args) |
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| 277 | def visitGetattr(self, node, *args): |
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| 278 | self.visit(node.expr, *args) |
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| 279 | self.buf.write(".%s" % node.attrname) |
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| 280 | def visitSub(self, node, *args): |
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| 281 | self.operator("-", node, *args) |
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| 282 | def visitNot(self, node, *args): |
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| 283 | self.buf.write("not ") |
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| 284 | self.visit(node.expr) |
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| 285 | def visitDiv(self, node, *args): |
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| 286 | self.operator("/", node, *args) |
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| 287 | def visitFloorDiv(self, node, *args): |
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| 288 | self.operator("//", node, *args) |
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| 289 | def visitSubscript(self, node, *args): |
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| 290 | self.visit(node.expr) |
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| 291 | self.buf.write("[") |
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| 292 | [self.visit(x) for x in node.subs] |
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| 293 | self.buf.write("]") |
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| 294 | def visitUnarySub(self, node, *args): |
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| 295 | self.buf.write("-") |
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| 296 | self.visit(node.expr) |
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| 297 | def visitUnaryAdd(self, node, *args): |
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| 298 | self.buf.write("-") |
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| 299 | self.visit(node.expr) |
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| 300 | def visitSlice(self, node, *args): |
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| 301 | self.visit(node.expr) |
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| 302 | self.buf.write("[") |
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| 303 | if node.lower is not None: |
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| 304 | self.visit(node.lower) |
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| 305 | self.buf.write(":") |
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| 306 | if node.upper is not None: |
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| 307 | self.visit(node.upper) |
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| 308 | self.buf.write("]") |
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| 309 | def visitDict(self, node): |
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| 310 | self.buf.write("{") |
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| 311 | c = node.getChildren() |
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| 312 | for i in range(0, len(c), 2): |
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| 313 | self.visit(c[i]) |
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| 314 | self.buf.write(": ") |
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| 315 | self.visit(c[i+1]) |
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| 316 | if i<len(c) -2: |
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| 317 | self.buf.write(", ") |
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| 318 | self.buf.write("}") |
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| 319 | def visitTuple(self, node): |
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| 320 | self.buf.write("(") |
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| 321 | c = node.getChildren() |
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| 322 | for i in range(0, len(c)): |
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| 323 | self.visit(c[i]) |
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| 324 | if i<len(c) - 1: |
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| 325 | self.buf.write(", ") |
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| 326 | self.buf.write(")") |
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| 327 | def visitList(self, node): |
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| 328 | self.buf.write("[") |
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| 329 | c = node.getChildren() |
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| 330 | for i in range(0, len(c)): |
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| 331 | self.visit(c[i]) |
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| 332 | if i<len(c) - 1: |
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| 333 | self.buf.write(", ") |
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| 334 | self.buf.write("]") |
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| 335 | def visitListComp(self, node): |
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| 336 | self.buf.write("[") |
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| 337 | self.visit(node.expr) |
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| 338 | self.buf.write(" ") |
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| 339 | for n in node.quals: |
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| 340 | self.visit(n) |
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| 341 | self.buf.write("]") |
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| 342 | def visitListCompFor(self, node): |
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| 343 | self.buf.write(" for ") |
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| 344 | self.visit(node.assign) |
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| 345 | self.buf.write(" in ") |
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| 346 | self.visit(node.list) |
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| 347 | for n in node.ifs: |
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| 348 | self.visit(n) |
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| 349 | def visitListCompIf(self, node): |
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| 350 | self.buf.write(" if ") |
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| 351 | self.visit(node.test) |
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| 352 | def visitCompare(self, node): |
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| 353 | self.visit(node.expr) |
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| 354 | for tup in node.ops: |
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| 355 | self.buf.write(tup[0]) |
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| 356 | self.visit(tup[1]) |
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| 357 | def visitCallFunc(self, node, *args): |
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| 358 | self.visit(node.node) |
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| 359 | self.buf.write("(") |
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| 360 | if len(node.args): |
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| 361 | self.visit(node.args[0]) |
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| 362 | for a in node.args[1:]: |
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| 363 | self.buf.write(", ") |
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| 364 | self.visit(a) |
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| 365 | self.buf.write(")") |
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| 366 | |
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| 367 | class walker(visitor.ASTVisitor): |
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| 368 | def dispatch(self, node, *args): |
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| 369 | print "Node:", str(node) |
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| 370 | #print "dir:", dir(node) |
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| 371 | return visitor.ASTVisitor.dispatch(self, node, *args) |
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