[Python-ideas] Keyword same in right hand side of assignments (rev)

[hwpuschm at yahoo.de]

Thank you very much for correctly remarking
that the "definition" I formulated contradicts the examples I gave
and is therefore utterly inadecuate:

> It is proposed to introduce a Keyword "same",
> to be used in the right hand side of assignments, as
> follows:
>  
>   "xx = same + 5" or "...DELETED..." synonymous with "xx += 5"
>   "value =  2*same + 5"  synonymous with "value =*2;
> value +=5"
>   "switch = 1 - same"  synonymous with "switch *-1;
> switch +=1"
>   "lst = same + [5,6]"  synonymous with  "lst += [5,6]"
>
>   "lst = [5,6] + same" synonymous with  "...DELETED..."
>   "lst[2] = 1/same" synonymous with  "lst[2] **=-1"
>  
> and so on.

What I would like is to extend the augmented assignment
and make it easy to understand for naive readers.
I hope the following literary definition
is consistent enough to convey the correct meaning:
  "whenever it is possible, modify the target IN PLACE
  according to the right hand side expression.
  If it is not possible to do such a thing,
  substitute the target object with
  an object that is build according to the right hand side expression
  and subsequently deleted"

The following examples should be correct:
  "xx = same + 5"  synonymous with  "xx += 5"
  "value =  2*same + 5"  synonymous with  "value =*2; value +=5"
  "switch = 1 - same"  synonymous with  "switch *-1; switch +=1"
  "lst = same + [5,6]"  synonymous with  "lst += [5,6]"
  "lst[2] = 1/same" synonymous with  "lst[2] **=-1"
The following examples would be extensions:
  "lst = [5,6] + same" synonymous with
      "lst.reverse(); lst.extend([6,5]); lst.reverse()"
  "inmutable = same*(same+1)"  synonymous with
      "unused=inmutable+1; inmutable*=unused; del unused"

There seems to be no really simple expression for the above extensions,
and I take that as an indication
that the proposed feature could be quite useful.