[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
bug#27674: 26.0.50; cl-progv: strange scoping due to implementation
From: |
npostavs |
Subject: |
bug#27674: 26.0.50; cl-progv: strange scoping due to implementation |
Date: |
Wed, 12 Jul 2017 21:54:26 -0400 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/25.2.50 (gnu/linux) |
Michael Heerdegen <michael_heerdegen@web.de> writes:
> Eh - no. Maybe I have a wrong mental model. I thought that the free
> variable `x' in the lambda is (also) in the scope of the dynamical
> binding created by `progv', and because that binding is established
> inside the `let' establishing the lexical binding of `x', it would
> shadow the lexical binding.
Oh, you want lexical and dynamic binding on the same variable? I think
the answer is "don't do that".
> Why does the lambda still refer to the lexical binding?
Maybe it would be more obvious if we wrote it like this:
(let ((x 0))
(cl-progv (list (intern (read-string "Enter var: "))) (list 1)
(funcall (lambda () x))))
Clearly the inner x must refer to the lexical let-binding, right? Even
if the user happens to enter `x' at the prompt this remains true.
> Does a lexical binding always beat a dynamical one?
Yes, lexical analysis is performed first and then the names are thrown
away, so you can't even tell when the "same" variable has been
dynamically bound as well.
- bug#27674: 26.0.50; cl-progv: strange scoping due to implementation, Michael Heerdegen, 2017/07/12
- bug#27674: 26.0.50; cl-progv: strange scoping due to implementation, npostavs, 2017/07/12
- bug#27674: 26.0.50; cl-progv: strange scoping due to implementation, Michael Heerdegen, 2017/07/12
- bug#27674: 26.0.50; cl-progv: strange scoping due to implementation, npostavs, 2017/07/12
- bug#27674: 26.0.50; cl-progv: strange scoping due to implementation, Michael Heerdegen, 2017/07/12
- bug#27674: 26.0.50; cl-progv: strange scoping due to implementation,
npostavs <=
- bug#27674: 26.0.50; cl-progv: strange scoping due to implementation, Michael Heerdegen, 2017/07/12
- bug#27674: 26.0.50; cl-progv: strange scoping due to implementation, npostavs, 2017/07/12
- bug#27674: 26.0.50; cl-progv: strange scoping due to implementation, Roland Winkler, 2017/07/13
- bug#27674: 26.0.50; cl-progv: strange scoping due to implementation, Noam Postavsky, 2017/07/13
- bug#27674: 26.0.50; cl-progv: strange scoping due to implementation, Michael Heerdegen, 2017/07/14
- bug#27674: 26.0.50; cl-progv: strange scoping due to implementation, Roland Winkler, 2017/07/15
- bug#27674: 26.0.50; cl-progv: strange scoping due to implementation, Michael Heerdegen, 2017/07/14
- bug#27674: 26.0.50; cl-progv: strange scoping due to implementation, Stefan Monnier, 2017/07/19