cmlenz@794: # -*- coding: utf-8 -*-
cmlenz@794: #
cmlenz@854: # Copyright (C) 2008-2009 Edgewall Software
cmlenz@794: # All rights reserved.
cmlenz@794: #
cmlenz@794: # This software is licensed as described in the file COPYING, which
cmlenz@794: # you should have received as part of this distribution. The terms
cmlenz@794: # are also available at http://genshi.edgewall.org/wiki/License.
cmlenz@794: #
cmlenz@794: # This software consists of voluntary contributions made by many
cmlenz@794: # individuals. For the exact contribution history, see the revision
cmlenz@794: # history and logs, available at http://genshi.edgewall.org/log/.
cmlenz@794: 
cmlenz@794: """Support classes for generating code from abstract syntax trees."""
cmlenz@794: 
cmlenz@794: try:
cmlenz@794:     import _ast
cmlenz@794: except ImportError:
cmlenz@794:     from genshi.template.ast24 import _ast, parse
cmlenz@794: else:
cmlenz@794:     def parse(source, mode):
cmlenz@794:         return compile(source, '', mode, _ast.PyCF_ONLY_AST)
cmlenz@794: 
cmlenz@794: 
cmlenz@794: __docformat__ = 'restructuredtext en'
cmlenz@794: 
cmlenz@794: 
cmlenz@794: class ASTCodeGenerator(object):
cmlenz@794:     """General purpose base class for AST transformations.
cmlenz@794: 
cmlenz@794:     Every visitor method can be overridden to return an AST node that has been
cmlenz@794:     altered or replaced in some way.
cmlenz@794:     """
cmlenz@794:     def __init__(self, tree):
cmlenz@794:         self.lines_info = []
cmlenz@794:         self.line_info = None
cmlenz@794:         self.code = ''
cmlenz@794:         self.line = None
cmlenz@794:         self.last = None
cmlenz@794:         self.indent = 0
cmlenz@794:         self.blame_stack = []
cmlenz@794:         self.visit(tree)
cmlenz@794:         if self.line.strip():
cmlenz@794:             self.code += self.line + '\n'
cmlenz@794:             self.lines_info.append(self.line_info)
cmlenz@794:         self.line = None
cmlenz@794:         self.line_info = None
cmlenz@794: 
cmlenz@794:     def _change_indent(self, delta):
cmlenz@794:         self.indent += delta
cmlenz@794: 
cmlenz@794:     def _new_line(self):
cmlenz@794:         if self.line is not None:
cmlenz@794:             self.code += self.line + '\n'
cmlenz@794:             self.lines_info.append(self.line_info)
cmlenz@794:         self.line = ' '*4*self.indent
cmlenz@794:         if len(self.blame_stack) == 0:
cmlenz@794:             self.line_info = []
cmlenz@794:             self.last = None
cmlenz@794:         else:
cmlenz@794:             self.line_info = [(0, self.blame_stack[-1],)]
cmlenz@794:             self.last = self.blame_stack[-1]
cmlenz@794: 
cmlenz@794:     def _write(self, s):
cmlenz@794:         if len(s) == 0:
cmlenz@794:             return
cmlenz@794:         if len(self.blame_stack) == 0:
cmlenz@794:             if self.last is not None:
cmlenz@794:                 self.last = None
cmlenz@794:                 self.line_info.append((len(self.line), self.last))
cmlenz@794:         else:
cmlenz@794:             if self.last != self.blame_stack[-1]:
cmlenz@794:                 self.last = self.blame_stack[-1]
cmlenz@794:                 self.line_info.append((len(self.line), self.last))
cmlenz@794:         self.line += s
cmlenz@794: 
cmlenz@794:     def visit(self, node):
cmlenz@794:         if node is None:
cmlenz@794:             return None
cmlenz@794:         if type(node) is tuple:
cmlenz@794:             return tuple([self.visit(n) for n in node])
cmlenz@794:         try:
cmlenz@794:             self.blame_stack.append((node.lineno, node.col_offset,))
cmlenz@794:             info = True
cmlenz@794:         except AttributeError:
cmlenz@794:             info = False
cmlenz@794:         visitor = getattr(self, 'visit_%s' % node.__class__.__name__, None)
cmlenz@794:         if visitor is None:
cmlenz@794:             raise Exception('Unhandled node type %r' % type(node))
cmlenz@794:         ret = visitor(node)
cmlenz@794:         if info:
cmlenz@794:             self.blame_stack.pop()
cmlenz@794:         return ret
cmlenz@794: 
cmlenz@794:     def visit_Module(self, node):
cmlenz@794:         for n in node.body:
cmlenz@794:             self.visit(n)
cmlenz@794:     visit_Interactive = visit_Module
cmlenz@794:     visit_Suite = visit_Module
cmlenz@794: 
cmlenz@794:     def visit_Expression(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         return self.visit(node.body)
cmlenz@794: 
cmlenz@794:     # arguments = (expr* args, identifier? vararg,
cmlenz@802:     #              identifier? kwarg, expr* defaults)
cmlenz@794:     def visit_arguments(self, node):
cmlenz@794:         first = True
cmlenz@802:         no_default_count = len(node.args) - len(node.defaults)
cmlenz@794:         for i, arg in enumerate(node.args):
cmlenz@794:             if not first:
cmlenz@794:                 self._write(', ')
cmlenz@794:             else:
cmlenz@794:                 first = False
cmlenz@794:             self.visit(arg)
cmlenz@802:             if i >= no_default_count:
cmlenz@794:                 self._write('=')
cmlenz@802:                 self.visit(node.defaults[i - no_default_count])
cmlenz@794:         if getattr(node, 'vararg', None):
cmlenz@794:             if not first:
cmlenz@794:                 self._write(', ')
cmlenz@794:             else:
cmlenz@794:                 first = False
cmlenz@794:             self._write('*' + node.vararg)
cmlenz@794:         if getattr(node, 'kwarg', None):
cmlenz@794:             if not first:
cmlenz@794:                 self._write(', ')
cmlenz@794:             else:
cmlenz@794:                 first = False
cmlenz@794:             self._write('**' + node.kwarg)
cmlenz@794: 
cmlenz@794:     # FunctionDef(identifier name, arguments args,
cmlenz@879:     #                           stmt* body, expr* decorator_list)
cmlenz@794:     def visit_FunctionDef(self, node):
cmlenz@879:         decarators = ()
cmlenz@879:         if hasattr(node, 'decorator_list'):
cmlenz@879:             decorators = getattr(node, 'decorator_list')
cmlenz@879:         else: # different name in earlier Python versions
cmlenz@879:             decorators = getattr(node, 'decorators', ())
cmlenz@879:         for decorator in decorators:
cmlenz@794:             self._new_line()
cmlenz@794:             self._write('@')
cmlenz@794:             self.visit(decorator)
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('def ' + node.name + '(')
cmlenz@794:         self.visit(node.args)
cmlenz@794:         self._write('):')
cmlenz@794:         self._change_indent(1)
cmlenz@794:         for statement in node.body:
cmlenz@794:             self.visit(statement)
cmlenz@794:         self._change_indent(-1)
cmlenz@794: 
cmlenz@794:     # ClassDef(identifier name, expr* bases, stmt* body)
cmlenz@794:     def visit_ClassDef(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('class ' + node.name)
cmlenz@794:         if node.bases:
cmlenz@794:             self._write('(')
cmlenz@794:             self.visit(node.bases[0])
cmlenz@794:             for base in node.bases[1:]:
cmlenz@794:                 self._write(', ')
cmlenz@794:                 self.visit(base)
cmlenz@794:             self._write(')')
cmlenz@794:         self._write(':')
cmlenz@794:         self._change_indent(1)
cmlenz@794:         for statement in node.body:
cmlenz@794:             self.visit(statement)
cmlenz@794:         self._change_indent(-1)
cmlenz@794: 
cmlenz@794:     # Return(expr? value)
cmlenz@794:     def visit_Return(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('return')
cmlenz@794:         if getattr(node, 'value', None):
cmlenz@794:             self._write(' ')
cmlenz@794:             self.visit(node.value)
cmlenz@794: 
cmlenz@794:     # Delete(expr* targets)
cmlenz@794:     def visit_Delete(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('del ')
cmlenz@794:         self.visit(node.targets[0])
cmlenz@794:         for target in node.targets[1:]:
cmlenz@794:             self._write(', ')
cmlenz@794:             self.visit(target)
cmlenz@794: 
cmlenz@794:     # Assign(expr* targets, expr value)
cmlenz@794:     def visit_Assign(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         for target in node.targets:
cmlenz@794:             self.visit(target)
cmlenz@794:             self._write(' = ')
cmlenz@794:         self.visit(node.value)
cmlenz@794: 
cmlenz@794:     # AugAssign(expr target, operator op, expr value)
cmlenz@794:     def visit_AugAssign(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self.visit(node.target)
cmlenz@794:         self._write(' ' + self.binary_operators[node.op.__class__] + '= ')
cmlenz@794:         self.visit(node.value)
cmlenz@794: 
cmlenz@794:     # Print(expr? dest, expr* values, bool nl)
cmlenz@794:     def visit_Print(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('print')
cmlenz@794:         if getattr(node, 'dest', None):
cmlenz@794:             self._write(' >> ')
cmlenz@794:             self.visit(node.dest)
cmlenz@794:             if getattr(node, 'values', None):
cmlenz@794:                 self._write(', ')
cmlenz@806:         else:
cmlenz@806:             self._write(' ')
cmlenz@794:         if getattr(node, 'values', None):
cmlenz@794:             self.visit(node.values[0])
cmlenz@794:             for value in node.values[1:]:
cmlenz@794:                 self._write(', ')
cmlenz@794:                 self.visit(value)
cmlenz@794:         if not node.nl:
cmlenz@794:             self._write(',')
cmlenz@794: 
cmlenz@794:     # For(expr target, expr iter, stmt* body, stmt* orelse)
cmlenz@794:     def visit_For(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('for ')
cmlenz@794:         self.visit(node.target)
cmlenz@794:         self._write(' in ')
cmlenz@794:         self.visit(node.iter)
cmlenz@794:         self._write(':')
cmlenz@794:         self._change_indent(1)
cmlenz@794:         for statement in node.body:
cmlenz@794:             self.visit(statement)
cmlenz@794:         self._change_indent(-1)
cmlenz@794:         if getattr(node, 'orelse', None):
cmlenz@794:             self._new_line()
cmlenz@794:             self._write('else:')
cmlenz@794:             self._change_indent(1)
cmlenz@794:             for statement in node.orelse:
cmlenz@794:                 self.visit(statement)
cmlenz@794:             self._change_indent(-1)
cmlenz@794: 
cmlenz@794:     # While(expr test, stmt* body, stmt* orelse)
cmlenz@794:     def visit_While(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('while ')
cmlenz@794:         self.visit(node.test)
cmlenz@794:         self._write(':')
cmlenz@794:         self._change_indent(1)
cmlenz@794:         for statement in node.body:
cmlenz@794:             self.visit(statement)
cmlenz@794:         self._change_indent(-1)
cmlenz@794:         if getattr(node, 'orelse', None):
cmlenz@794:             self._new_line()
cmlenz@794:             self._write('else:')
cmlenz@794:             self._change_indent(1)
cmlenz@794:             for statement in node.orelse:
cmlenz@794:                 self.visit(statement)
cmlenz@794:             self._change_indent(-1)
cmlenz@794: 
cmlenz@794:     # If(expr test, stmt* body, stmt* orelse)
cmlenz@794:     def visit_If(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('if ')
cmlenz@794:         self.visit(node.test)
cmlenz@794:         self._write(':')
cmlenz@794:         self._change_indent(1)
cmlenz@794:         for statement in node.body:
cmlenz@794:             self.visit(statement)
cmlenz@794:         self._change_indent(-1)
cmlenz@794:         if getattr(node, 'orelse', None):
cmlenz@794:             self._new_line()
cmlenz@794:             self._write('else:')
cmlenz@794:             self._change_indent(1)
cmlenz@794:             for statement in node.orelse:
cmlenz@794:                 self.visit(statement)
cmlenz@794:             self._change_indent(-1)
cmlenz@794: 
cmlenz@794:     # With(expr context_expr, expr? optional_vars, stmt* body)
cmlenz@794:     def visit_With(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('with ')
cmlenz@794:         self.visit(node.context_expr)
cmlenz@794:         if getattr(node, 'optional_vars', None):
cmlenz@794:             self._write(' as ')
cmlenz@794:             self.visit(node.optional_vars)
cmlenz@794:         self._write(':')
cmlenz@794:         self._change_indent(1)
cmlenz@794:         for statement in node.body:
cmlenz@794:             self.visit(statement)
cmlenz@794:         self._change_indent(-1)
cmlenz@794: 
cmlenz@794: 
cmlenz@794:     # Raise(expr? type, expr? inst, expr? tback)
cmlenz@794:     def visit_Raise(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('raise')
cmlenz@794:         if not node.type:
cmlenz@794:             return
cmlenz@794:         self._write(' ')
cmlenz@794:         self.visit(node.type)
cmlenz@794:         if not node.inst:
cmlenz@794:             return
cmlenz@794:         self._write(', ')
cmlenz@794:         self.visit(node.inst)
cmlenz@794:         if not node.tback:
cmlenz@794:             return
cmlenz@794:         self._write(', ')
cmlenz@794:         self.visit(node.tback)
cmlenz@794: 
cmlenz@794:     # TryExcept(stmt* body, excepthandler* handlers, stmt* orelse)
cmlenz@794:     def visit_TryExcept(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('try:')
cmlenz@794:         self._change_indent(1)
cmlenz@794:         for statement in node.body:
cmlenz@794:             self.visit(statement)
cmlenz@794:         self._change_indent(-1)
cmlenz@794:         if getattr(node, 'handlers', None):
cmlenz@794:             for handler in node.handlers:
cmlenz@794:                 self.visit(handler)
cmlenz@794:         self._new_line()
cmlenz@794:         if getattr(node, 'orelse', None):
cmlenz@794:             self._write('else:')
cmlenz@794:             self._change_indent(1)
cmlenz@794:             for statement in node.orelse:
cmlenz@794:                 self.visit(statement)
cmlenz@794:             self._change_indent(-1)
cmlenz@794: 
cmlenz@794:     # excepthandler = (expr? type, expr? name, stmt* body)
cmlenz@794:     def visit_ExceptHandler(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('except')
cmlenz@794:         if getattr(node, 'type', None):
cmlenz@794:             self._write(' ')
cmlenz@794:             self.visit(node.type)
cmlenz@794:         if getattr(node, 'name', None):
cmlenz@794:             self._write(', ')
cmlenz@794:             self.visit(node.name)
cmlenz@794:         self._write(':')
cmlenz@794:         self._change_indent(1)
cmlenz@794:         for statement in node.body:
cmlenz@794:             self.visit(statement)
cmlenz@794:         self._change_indent(-1)
cmlenz@794:     visit_excepthandler = visit_ExceptHandler
cmlenz@794: 
cmlenz@794:     # TryFinally(stmt* body, stmt* finalbody)
cmlenz@794:     def visit_TryFinally(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('try:')
cmlenz@794:         self._change_indent(1)
cmlenz@794:         for statement in node.body:
cmlenz@794:             self.visit(statement)
cmlenz@794:         self._change_indent(-1)
cmlenz@794: 
cmlenz@794:         if getattr(node, 'finalbody', None):
cmlenz@794:             self._new_line()
cmlenz@794:             self._write('finally:')
cmlenz@794:             self._change_indent(1)
cmlenz@794:             for statement in node.finalbody:
cmlenz@794:                 self.visit(statement)
cmlenz@794:             self._change_indent(-1)
cmlenz@794: 
cmlenz@794:     # Assert(expr test, expr? msg)
cmlenz@794:     def visit_Assert(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('assert ')
cmlenz@794:         self.visit(node.test)
cmlenz@794:         if getattr(node, 'msg', None):
cmlenz@794:             self._write(', ')
cmlenz@794:             self.visit(node.msg)
cmlenz@794: 
cmlenz@794:     def visit_alias(self, node):
cmlenz@794:         self._write(node.name)
cmlenz@794:         if getattr(node, 'asname', None):
cmlenz@794:             self._write(' as ')
cmlenz@794:             self._write(node.asname)
cmlenz@794: 
cmlenz@794:     # Import(alias* names)
cmlenz@794:     def visit_Import(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('import ')
cmlenz@794:         self.visit(node.names[0])
cmlenz@794:         for name in node.names[1:]:
cmlenz@794:             self._write(', ')
cmlenz@794:             self.visit(name)
cmlenz@794: 
cmlenz@794:     # ImportFrom(identifier module, alias* names, int? level)
cmlenz@794:     def visit_ImportFrom(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('from ')
cmlenz@794:         if node.level:
cmlenz@794:             self._write('.' * node.level)
cmlenz@794:         self._write(node.module)
cmlenz@794:         self._write(' import ')
cmlenz@794:         self.visit(node.names[0])
cmlenz@794:         for name in node.names[1:]:
cmlenz@794:             self._write(', ')
cmlenz@794:             self.visit(name)
cmlenz@794: 
cmlenz@794:     # Exec(expr body, expr? globals, expr? locals)
cmlenz@794:     def visit_Exec(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('exec ')
cmlenz@794:         self.visit(node.body)
cmlenz@794:         if not node.globals:
cmlenz@794:             return
cmlenz@794:         self._write(', ')
cmlenz@794:         self.visit(node.globals)
cmlenz@794:         if not node.locals:
cmlenz@794:             return
cmlenz@794:         self._write(', ')
cmlenz@794:         self.visit(node.locals)
cmlenz@794: 
cmlenz@794:     # Global(identifier* names)
cmlenz@794:     def visit_Global(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('global ')
cmlenz@794:         self.visit(node.names[0])
cmlenz@794:         for name in node.names[1:]:
cmlenz@794:             self._write(', ')
cmlenz@794:             self.visit(name)
cmlenz@794: 
cmlenz@794:     # Expr(expr value)
cmlenz@794:     def visit_Expr(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self.visit(node.value)
cmlenz@794: 
cmlenz@794:     # Pass
cmlenz@794:     def visit_Pass(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('pass')
cmlenz@794: 
cmlenz@794:     # Break
cmlenz@794:     def visit_Break(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('break')
cmlenz@794: 
cmlenz@794:     # Continue
cmlenz@794:     def visit_Continue(self, node):
cmlenz@794:         self._new_line()
cmlenz@794:         self._write('continue')
cmlenz@794: 
cmlenz@794:     ### EXPRESSIONS
cmlenz@794:     def with_parens(f):
cmlenz@794:         def _f(self, node):
cmlenz@794:             self._write('(')
cmlenz@794:             f(self, node)
cmlenz@794:             self._write(')')
cmlenz@794:         return _f
cmlenz@794: 
cmlenz@794:     bool_operators = {_ast.And: 'and', _ast.Or: 'or'}
cmlenz@794: 
cmlenz@794:     # BoolOp(boolop op, expr* values)
cmlenz@794:     @with_parens
cmlenz@794:     def visit_BoolOp(self, node):
cmlenz@794:         joiner = ' ' + self.bool_operators[node.op.__class__] + ' '
cmlenz@794:         self.visit(node.values[0])
cmlenz@794:         for value in node.values[1:]:
cmlenz@794:             self._write(joiner)
cmlenz@794:             self.visit(value)
cmlenz@794: 
cmlenz@794:     binary_operators = {
cmlenz@794:         _ast.Add: '+',
cmlenz@794:         _ast.Sub: '-',
cmlenz@794:         _ast.Mult: '*',
cmlenz@794:         _ast.Div: '/',
cmlenz@794:         _ast.Mod: '%',
cmlenz@794:         _ast.Pow: '**',
cmlenz@794:         _ast.LShift: '<<',
cmlenz@794:         _ast.RShift: '>>',
cmlenz@794:         _ast.BitOr: '|',
cmlenz@794:         _ast.BitXor: '^',
cmlenz@794:         _ast.BitAnd: '&',
cmlenz@794:         _ast.FloorDiv: '//'
cmlenz@794:     }
cmlenz@794: 
cmlenz@794:     # BinOp(expr left, operator op, expr right)
cmlenz@794:     @with_parens
cmlenz@794:     def visit_BinOp(self, node):
cmlenz@794:         self.visit(node.left)
cmlenz@794:         self._write(' ' + self.binary_operators[node.op.__class__] + ' ')
cmlenz@794:         self.visit(node.right)
cmlenz@794: 
cmlenz@794:     unary_operators = {
cmlenz@794:         _ast.Invert: '~',
cmlenz@794:         _ast.Not: 'not',
cmlenz@794:         _ast.UAdd: '+',
cmlenz@794:         _ast.USub: '-',
cmlenz@794:     }
cmlenz@794: 
cmlenz@794:     # UnaryOp(unaryop op, expr operand)
cmlenz@794:     def visit_UnaryOp(self, node):
cmlenz@794:         self._write(self.unary_operators[node.op.__class__] + ' ')
cmlenz@794:         self.visit(node.operand)
cmlenz@794: 
cmlenz@794:     # Lambda(arguments args, expr body)
cmlenz@794:     @with_parens
cmlenz@794:     def visit_Lambda(self, node):
cmlenz@794:         self._write('lambda ')
cmlenz@794:         self.visit(node.args)
cmlenz@794:         self._write(': ')
cmlenz@794:         self.visit(node.body)
cmlenz@794: 
cmlenz@794:     # IfExp(expr test, expr body, expr orelse)
cmlenz@794:     @with_parens
cmlenz@794:     def visit_IfExp(self, node):
cmlenz@794:         self.visit(node.body)
cmlenz@794:         self._write(' if ')
cmlenz@794:         self.visit(node.test)
cmlenz@794:         self._write(' else ')
cmlenz@794:         self.visit(node.orelse)
cmlenz@794: 
cmlenz@794:     # Dict(expr* keys, expr* values)
cmlenz@794:     def visit_Dict(self, node):
cmlenz@794:         self._write('{')
cmlenz@794:         for key, value in zip(node.keys, node.values):
cmlenz@794:             self.visit(key)
cmlenz@794:             self._write(': ')
cmlenz@794:             self.visit(value)
cmlenz@794:             self._write(', ')
cmlenz@794:         self._write('}')
cmlenz@794: 
cmlenz@794:     # ListComp(expr elt, comprehension* generators)
cmlenz@794:     def visit_ListComp(self, node):
cmlenz@794:         self._write('[')
cmlenz@794:         self.visit(node.elt)
cmlenz@794:         for generator in node.generators:
cmlenz@794:             # comprehension = (expr target, expr iter, expr* ifs)
cmlenz@794:             self._write(' for ')
cmlenz@794:             self.visit(generator.target)
cmlenz@794:             self._write(' in ')
cmlenz@794:             self.visit(generator.iter)
cmlenz@794:             for ifexpr in generator.ifs:
cmlenz@794:                 self._write(' if ')
cmlenz@794:                 self.visit(ifexpr)
cmlenz@794:         self._write(']')
cmlenz@794: 
cmlenz@794:     # GeneratorExp(expr elt, comprehension* generators)
cmlenz@794:     def visit_GeneratorExp(self, node):
cmlenz@794:         self._write('(')
cmlenz@794:         self.visit(node.elt)
cmlenz@794:         for generator in node.generators:
cmlenz@794:             # comprehension = (expr target, expr iter, expr* ifs)
cmlenz@794:             self._write(' for ')
cmlenz@794:             self.visit(generator.target)
cmlenz@794:             self._write(' in ')
cmlenz@794:             self.visit(generator.iter)
cmlenz@794:             for ifexpr in generator.ifs:
cmlenz@794:                 self._write(' if ')
cmlenz@794:                 self.visit(ifexpr)
cmlenz@794:         self._write(')')
cmlenz@794: 
cmlenz@794:     # Yield(expr? value)
cmlenz@794:     def visit_Yield(self, node):
cmlenz@794:         self._write('yield')
cmlenz@794:         if getattr(node, 'value', None):
cmlenz@794:             self._write(' ')
cmlenz@794:             self.visit(node.value)
cmlenz@794: 
cmlenz@794:     comparision_operators = {
cmlenz@794:         _ast.Eq: '==',
cmlenz@794:         _ast.NotEq: '!=',
cmlenz@794:         _ast.Lt: '<',
cmlenz@794:         _ast.LtE: '<=',
cmlenz@794:         _ast.Gt: '>',
cmlenz@794:         _ast.GtE: '>=',
cmlenz@794:         _ast.Is: 'is',
cmlenz@794:         _ast.IsNot: 'is not',
cmlenz@794:         _ast.In: 'in',
cmlenz@794:         _ast.NotIn: 'not in',
cmlenz@794:     }
cmlenz@794: 
cmlenz@794:     # Compare(expr left, cmpop* ops, expr* comparators)
cmlenz@794:     @with_parens
cmlenz@794:     def visit_Compare(self, node):
cmlenz@794:         self.visit(node.left)
cmlenz@794:         for op, comparator in zip(node.ops, node.comparators):
cmlenz@794:             self._write(' ' + self.comparision_operators[op.__class__] + ' ')
cmlenz@794:             self.visit(comparator)
cmlenz@794: 
cmlenz@794:     # Call(expr func, expr* args, keyword* keywords,
cmlenz@794:     #                         expr? starargs, expr? kwargs)
cmlenz@794:     def visit_Call(self, node):
cmlenz@794:         self.visit(node.func)
cmlenz@794:         self._write('(')
cmlenz@794:         first = True
cmlenz@794:         for arg in node.args:
cmlenz@794:             if not first:
cmlenz@794:                 self._write(', ')
cmlenz@794:             first = False
cmlenz@794:             self.visit(arg)
cmlenz@794: 
cmlenz@794:         for keyword in node.keywords:
cmlenz@794:             if not first:
cmlenz@794:                 self._write(', ')
cmlenz@794:             first = False
cmlenz@794:             # keyword = (identifier arg, expr value)
cmlenz@794:             self._write(keyword.arg)
cmlenz@794:             self._write('=')
cmlenz@794:             self.visit(keyword.value)
cmlenz@794:         if getattr(node, 'starargs', None):
cmlenz@794:             if not first:
cmlenz@794:                 self._write(', ')
cmlenz@794:             first = False
cmlenz@794:             self._write('*')
cmlenz@794:             self.visit(node.starargs)
cmlenz@794: 
cmlenz@794:         if getattr(node, 'kwargs', None):
cmlenz@794:             if not first:
cmlenz@794:                 self._write(', ')
cmlenz@794:             first = False
cmlenz@794:             self._write('**')
cmlenz@794:             self.visit(node.kwargs)
cmlenz@794:         self._write(')')
cmlenz@794: 
cmlenz@794:     # Repr(expr value)
cmlenz@794:     def visit_Repr(self, node):
cmlenz@794:         self._write('`')
cmlenz@794:         self.visit(node.value)
cmlenz@794:         self._write('`')
cmlenz@794: 
cmlenz@794:     # Num(object n)
cmlenz@794:     def visit_Num(self, node):
cmlenz@794:         self._write(repr(node.n))
cmlenz@794: 
cmlenz@794:     # Str(string s)
cmlenz@794:     def visit_Str(self, node):
cmlenz@794:         self._write(repr(node.s))
cmlenz@794: 
cmlenz@794:     # Attribute(expr value, identifier attr, expr_context ctx)
cmlenz@794:     def visit_Attribute(self, node):
cmlenz@794:         self.visit(node.value)
cmlenz@794:         self._write('.')
cmlenz@794:         self._write(node.attr)
cmlenz@794: 
cmlenz@794:     # Subscript(expr value, slice slice, expr_context ctx)
cmlenz@794:     def visit_Subscript(self, node):
cmlenz@794:         self.visit(node.value)
cmlenz@794:         self._write('[')
cmlenz@794:         def _process_slice(node):
cmlenz@794:             if isinstance(node, _ast.Ellipsis):
cmlenz@794:                 self._write('...')
cmlenz@794:             elif isinstance(node, _ast.Slice):
cmlenz@794:                 if getattr(node, 'lower', 'None'):
cmlenz@794:                     self.visit(node.lower)
cmlenz@794:                 self._write(':')
cmlenz@794:                 if getattr(node, 'upper', None):
cmlenz@794:                     self.visit(node.upper)
cmlenz@794:                 if getattr(node, 'step', None):
cmlenz@794:                     self._write(':')
cmlenz@794:                     self.visit(node.step)
cmlenz@794:             elif isinstance(node, _ast.Index):
cmlenz@794:                 self.visit(node.value)
cmlenz@794:             elif isinstance(node, _ast.ExtSlice):
cmlenz@794:                 self.visit(node.dims[0])
cmlenz@794:                 for dim in node.dims[1:]:
cmlenz@794:                     self._write(', ')
cmlenz@794:                     self.visit(dim)
cmlenz@794:             else:
cmlenz@855:                 raise NotImplemented('Slice type not implemented')
cmlenz@794:         _process_slice(node.slice)
cmlenz@794:         self._write(']')
cmlenz@794: 
cmlenz@794:     # Name(identifier id, expr_context ctx)
cmlenz@794:     def visit_Name(self, node):
cmlenz@794:         self._write(node.id)
cmlenz@794: 
cmlenz@794:     # List(expr* elts, expr_context ctx)
cmlenz@794:     def visit_List(self, node):
cmlenz@794:         self._write('[')
cmlenz@794:         for elt in node.elts:
cmlenz@794:             self.visit(elt)
cmlenz@794:             self._write(', ')
cmlenz@794:         self._write(']')
cmlenz@794: 
cmlenz@794:     # Tuple(expr *elts, expr_context ctx)
cmlenz@794:     def visit_Tuple(self, node):
cmlenz@794:         self._write('(')
cmlenz@794:         for elt in node.elts:
cmlenz@794:             self.visit(elt)
cmlenz@794:             self._write(', ')
cmlenz@794:         self._write(')')
cmlenz@794: 
cmlenz@794: 
cmlenz@794: class ASTTransformer(object):
cmlenz@794:     """General purpose base class for AST transformations.
cmlenz@794:     
cmlenz@794:     Every visitor method can be overridden to return an AST node that has been
cmlenz@794:     altered or replaced in some way.
cmlenz@794:     """
cmlenz@794: 
cmlenz@794:     def visit(self, node):
cmlenz@794:         if node is None:
cmlenz@794:             return None
cmlenz@794:         if type(node) is tuple:
cmlenz@794:             return tuple([self.visit(n) for n in node])
cmlenz@794:         visitor = getattr(self, 'visit_%s' % node.__class__.__name__, None)
cmlenz@794:         if visitor is None:
cmlenz@794:             return node
cmlenz@794:         return visitor(node)
cmlenz@794: 
cmlenz@794:     def _clone(self, node):
cmlenz@794:         clone = node.__class__()
cmlenz@794:         for name in getattr(clone, '_attributes', ()):
cmlenz@794:             try:
cmlenz@794:                 setattr(clone, 'name', getattr(node, name))
cmlenz@794:             except AttributeError:
cmlenz@794:                 pass
cmlenz@794:         for name in clone._fields:
cmlenz@794:             try:
cmlenz@794:                 value = getattr(node, name)
cmlenz@794:             except AttributeError:
cmlenz@794:                 pass
cmlenz@794:             else:
cmlenz@794:                 if value is None:
cmlenz@794:                     pass
cmlenz@794:                 elif isinstance(value, list):
cmlenz@794:                     value = [self.visit(x) for x in value]
cmlenz@794:                 elif isinstance(value, tuple):
cmlenz@794:                     value = tuple(self.visit(x) for x in value)
cmlenz@794:                 else: 
cmlenz@794:                     value = self.visit(value)
cmlenz@794:                 setattr(clone, name, value)
cmlenz@794:         return clone
cmlenz@794: 
cmlenz@794:     visit_Module = _clone
cmlenz@794:     visit_Interactive = _clone
cmlenz@794:     visit_Expression = _clone
cmlenz@794:     visit_Suite = _clone
cmlenz@794: 
cmlenz@794:     visit_FunctionDef = _clone
cmlenz@794:     visit_ClassDef = _clone
cmlenz@794:     visit_Return = _clone
cmlenz@794:     visit_Delete = _clone
cmlenz@794:     visit_Assign = _clone
cmlenz@794:     visit_AugAssign = _clone
cmlenz@794:     visit_Print = _clone
cmlenz@794:     visit_For = _clone
cmlenz@794:     visit_While = _clone
cmlenz@794:     visit_If = _clone
cmlenz@794:     visit_With = _clone
cmlenz@794:     visit_Raise = _clone
cmlenz@794:     visit_TryExcept = _clone
cmlenz@794:     visit_TryFinally = _clone
cmlenz@794:     visit_Assert = _clone
cmlenz@794: 
cmlenz@794:     visit_Import = _clone
cmlenz@794:     visit_ImportFrom = _clone
cmlenz@794:     visit_Exec = _clone
cmlenz@794:     visit_Global = _clone
cmlenz@794:     visit_Expr = _clone
cmlenz@794:     # Pass, Break, Continue don't need to be copied
cmlenz@794: 
cmlenz@794:     visit_BoolOp = _clone
cmlenz@794:     visit_BinOp = _clone
cmlenz@794:     visit_UnaryOp = _clone
cmlenz@794:     visit_Lambda = _clone
cmlenz@794:     visit_IfExp = _clone
cmlenz@794:     visit_Dict = _clone
cmlenz@794:     visit_ListComp = _clone
cmlenz@794:     visit_GeneratorExp = _clone
cmlenz@794:     visit_Yield = _clone
cmlenz@794:     visit_Compare = _clone
cmlenz@794:     visit_Call = _clone
cmlenz@794:     visit_Repr = _clone
cmlenz@794:     # Num, Str don't need to be copied
cmlenz@794: 
cmlenz@794:     visit_Attribute = _clone
cmlenz@794:     visit_Subscript = _clone
cmlenz@794:     visit_Name = _clone
cmlenz@794:     visit_List = _clone
cmlenz@794:     visit_Tuple = _clone
cmlenz@794: 
cmlenz@794:     visit_comprehension = _clone
cmlenz@794:     visit_excepthandler = _clone
cmlenz@794:     visit_arguments = _clone
cmlenz@794:     visit_keyword = _clone
cmlenz@794:     visit_alias = _clone
cmlenz@794: 
cmlenz@794:     visit_Slice = _clone
cmlenz@794:     visit_ExtSlice = _clone
cmlenz@794:     visit_Index = _clone
cmlenz@794: 
cmlenz@794:     del _clone