1  """Fixer for generator.throw(E, V, T).
       2  
       3  g.throw(E)       -> g.throw(E)
       4  g.throw(E, V)    -> g.throw(E(V))
       5  g.throw(E, V, T) -> g.throw(E(V).with_traceback(T))
       6  
       7  g.throw("foo"[, V[, T]]) will warn about string exceptions."""
       8  # Author: Collin Winter
       9  
      10  # Local imports
      11  from .. import pytree
      12  from ..pgen2 import token
      13  from .. import fixer_base
      14  from ..fixer_util import Name, Call, ArgList, Attr, is_tuple
      15  
      16  class ESC[4;38;5;81mFixThrow(ESC[4;38;5;149mfixer_baseESC[4;38;5;149m.ESC[4;38;5;149mBaseFix):
      17      BM_compatible = True
      18      PATTERN = """
      19      power< any trailer< '.' 'throw' >
      20             trailer< '(' args=arglist< exc=any ',' val=any [',' tb=any] > ')' >
      21      >
      22      |
      23      power< any trailer< '.' 'throw' > trailer< '(' exc=any ')' > >
      24      """
      25  
      26      def transform(self, node, results):
      27          syms = self.syms
      28  
      29          exc = results["exc"].clone()
      30          if exc.type is token.STRING:
      31              self.cannot_convert(node, "Python 3 does not support string exceptions")
      32              return
      33  
      34          # Leave "g.throw(E)" alone
      35          val = results.get("val")
      36          if val is None:
      37              return
      38  
      39          val = val.clone()
      40          if is_tuple(val):
      41              args = [c.clone() for c in val.children[1:-1]]
      42          else:
      43              val.prefix = ""
      44              args = [val]
      45  
      46          throw_args = results["args"]
      47  
      48          if "tb" in results:
      49              tb = results["tb"].clone()
      50              tb.prefix = ""
      51  
      52              e = Call(exc, args)
      53              with_tb = Attr(e, Name('with_traceback')) + [ArgList([tb])]
      54              throw_args.replace(pytree.Node(syms.power, with_tb))
      55          else:
      56              throw_args.replace(Call(exc, args))