[Python-ideas] Anonymous blocks (again):

[Juancarlo Añez]

On Mon, May 13, 2013 at 1:23 PM, Terry Jan Reedy <tjreedy at udel.edu> wrote:

> x = class (): pass
> x = with open(..):
> x = import itertools
> x = if True: y = 3
> x = <pick any statement other than expression/binding statements>
>

I can explain.

Expressions like "", [], (), {} are called "constructors" in programming
language theory, because the "construct" objects, and give them an initial
state.

In Python, functions, methods, and classes are objects too, and their
constructors are "class" and "def". But there's an asymmetry in the
language in that those two constructors don't produce an assignable value.

if, while, with, etc. are statements, not constructors. Other languages
make those return values too, but that's not the Python way of things.

Cheers,




-- 
Juancarlo *Añez*
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