[Python-ideas] Dart-like method cascading operator in Python

[Bruce Leban]

I like the basic idea. I agree with the sentiment that a colon should be
used to introduce it. Let me throw out some monkey wrenches. The following
uses :: as the syntax to begin the suite, that is:

obj::
    ..a = 1


is equivalent to

temp = obj
temp.a = 1


I'm assuming the .. must be followed by a statement (rewritten as above)
except in the case where the line ends with :: in which case it must be an
expression as in the example:

gnuplot.newPlot()::
    ..newPlot()::
        ..adjustPlot('x') ###

    ..adjustPlot('y')


is

temp1 = gnuplot.newPlot()
temp2 = temp1.newPlot()
temp2.adjustPlot('x') ###
temp1.adjustPlot('y')


Is there any way on the line marked ### to reference temp1?

Can I use .. in the middle of a statement/expression?

obj::
    x = ..x
    y = ..y + ..z

    ..f(..a, ..b)


equivalent to

temp = obj

x = temp.x
y = temp.y + temp.z
temp.f(temp.a, temp.b)


Is field/method access the only time where this is useful? Can I do this?

obj::
    .['a'] = 1
    .['b'] = 2


equivalent to

temp = obj
temp['a'] = 1
temp['b'] = 2


or this?

obj::
    .(1, 2)


equivalent to

temp = obj
obj(1, 2)


What about this very common code:

self.x = x
self.y = y

self.z = z + 1


it would be nice to have a shorthand for this that didn't require writing x
and y twice, but this doesn't do it for me and I don't have a better
suggestion:

self::

    .. = x

    .. = y

    ..z = z + 1



--- Bruce
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