[Python-ideas] Revised**12 PEP on Yield-From

[Scott David Daniels]

Jacob Holm wrote:
> ...
>     _i = iter(EXPR)
>     _m, _a = next, (_i,)
>     while 1:
>         try:
>             _y = _m(*_a)
>         except StopIteration as _e:
>             _r = _e.value
>             break
>         try:
>             _s = yield _y
>         except GeneratorExit as _e:
>             try:
>                 _m = _i.close
>             except AttributeError:
>                 pass
>             else:
>                 _m()
>             raise _e
>         except BaseException as _e:
>             _a = sys.exc_info()
>             try:
>                 _m = _i.throw
>             except AttributeError:
>                 raise _e
>         else:
>             if _s is None:
>                 _m, _a = next, (_i,)
>             else:
>                 _m, _a = _i.send, (_s,)
>     RESULT = _r
> 

Now that we passed the magic three or four threshold, is
it not easier to read if we pick some better names?

       _iter = iter(EXPR)
       _call, _arg = next, _iter
       while 1:
           try:
               _out = _call(_arg)
           except StopIteration as _except:
               _result = _except.value
               break
           try:
               _in = yield _out
           except GeneratorExit as _except:
               try:
                   _close = _iter.close
               except AttributeError:
                   pass
               else:
                   _close()
               raise _except
           except BaseException as _except:
               _a = sys.exc_info()
               try:
                   _call = _iter.throw
               except AttributeError:
                   raise _except
           else:
               if _in is None:
                   _call, _arg = next, _iter
               else:
                   _call, _arg = _iter.send, _in
       RESULT = _result

--Scott David Daniels
Scott.Daniels at Acm.Org