On 5/22/2018 5:32 PM, Kirill Balunov wrote:
Just one more variation on "assignment exression" syntax to make the list more complete :) Sorry, if something similar has already been suggested. The idea is to use function's call-like syntax in the from: `this( name = expr )`.
Functions names should be verbs. For this one, 'bind' or even better, 'let' as in 'let(name=expr)'
I'm not sure that such idea will find its
supporters and whether it is possible to implement it in a general way, but nevertheless. Below is a half- and slow-working prototype and some silly examples just for the sake of feeling the idea:import sys import ctypes def this(**assign): assert len(assign) == 1 [(name, value)] = assign.items() frame = sys._getframe(1) frame.f_locals[name] = value ctypes.pythonapi.PyFrame_LocalsToFast(ctypes.py_object(frame), ctypes.c_int(0)) return value Loop-and-a-half example with `dummy` function[1]: # in global scope everything works ok since locals is globals >>> while len( this( val = dummy() ) ) >= 0: ... print(val) [0, 1] [0, 1, 2] [0, 1, 2, 3] ... # needs to set the same local name to work inside function def func(): val = ... while len( this( val = dummy() ) ) >= 0: print(val) >>> # relies on the implicit underlying function's local `x` >>> [[this(x = (x+10)), x//10, x*10] for x in [100, 200, 300]] [[110, 11, 1100], [210, 21, 2100], [310, 31, 3100]]In this way it is somewhat possible to make an assignment in `while` and `if`headers right now, which covers 90% cases, but it is damn slow. Maybe be it is worth to make `this` magic call-alike object work fast...on the other hand does anyone like `this`?With kind regards, -gdg [1]: def dummy(ls = [0]): ls.append(ls[-1]+1) return ls _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
-- Terry Jan Reedy _______________________________________________ Python-ideas mailing list Python-ideas@python.org https://mail.python.org/mailman/listinfo/python-ideas Code of Conduct: http://python.org/psf/codeofconduct/
