Questions tagged [lexical-binding]
The lexical-binding tag has no usage guidance.
17
questions
7
votes
1answer
241 views
How to make sure no global variables have been created in a piece of lisp code?
I am writing some lisp code and I would like it not to mess with the global variables in the system. I am therefore being very careful to only use variables within the scope of the let special form.
...
1
vote
1answer
46 views
lexical-binding: How to create a let-bound function that recursively calls itself
The custom function below my-jump-to works after being evaluated in a scratch buffer, but does not work when I stick it into a library with lexical-binding non-nil in the header. When byte-compiling, ...
1
vote
1answer
111 views
How can I enable lexical binding for Elisp code in org-mode?
I have the following code:
#+begin_src elisp
(setq lexical-binding t)
(let ((a 1)) ; binding (1)
(let ((f (lambda () (print a))))
(let ((a 2)) ; ...
0
votes
0answers
23 views
Why symbol-value throws a void-variable error with a let form if lexical binding is on? [duplicate]
Here's a simple example from the manual:
;; Here the symbol ‘abracadabra’
;; is the symbol whose value is examined.
(let ((abracadabra 'foo))
(symbol-value 'abracadabra))
⇒ foo
Why does this ...
0
votes
0answers
12 views
Possible to name closures for easier reading of backtrace?
Let's say I write the following code:
(let* ((f (lambda () (debug))))
(funcall f))
This will produce the following backtrace:
Debugger entered: nil
(closure (bootstrap-version t) nil (debug))()
...
1
vote
1answer
50 views
Lexical binding in a process filter
The code constantly prints server-process: nil instead of the server process name:
-*- lexical-binding: t; -*-
(let* ((port 1234)
(server-process 'something))
(setq server-process
(...
1
vote
1answer
142 views
Updating code from lexical-let to lexical-binding: t
This code shows an elisp function (third example) using lexical-let, which is now passe as I understand. How would it be written today with lexical scope now being a quasi-built-in feature of elisp? ...
3
votes
1answer
30 views
Can I determine the difference of declaring (and not declaring) a file to use lexical-binding?
I have been trying to understand what difference it makes if you set the file variable lexical-binding to t for a particular source file.
As mentioned in emacswiki that in order to use lexical-...
4
votes
1answer
764 views
Global lexical-binding setting?
I've seen ;;; -*- lexical-binding: t; -*- at the top of a file and (setq lexical-binding t) as how to turn on lexical binding for elisp code, but is there a way to tell Emacs to simply always do ...
3
votes
2answers
137 views
byte-compile and lexical-binding
Could someone in the know please help me understand what's going on here:
;; -*- lexical-binding: t; -*-
(let* ((a 0))
(let* ((a 1))
(funcall (byte-compile (lambda () a)))))
;;=> 0
wat? Not ...
5
votes
1answer
216 views
About closure creation
After reading this article about readable closures, I check that:
Since closures are byte-code function objects, they print readably.
You can capture an environment in a closure, serialize it, ...
3
votes
3answers
471 views
How to avoid use of `lexical-let`
I have a macro that intends to creates a closure:
; -*- lexical-binding: t -*-
(defmacro repro ()
(let ((kmap-sym (gensym "kmap-")))
`(let ((,kmap-sym (make-sparse-keymap)))
(define-key ,...
1
vote
1answer
646 views
Using new features in emacs 27 generators
I want to try new features in emacs 26, I'm using emacs 27, generators and threads, but when I try to use on ielm buffer, I get the same error:
ELISP> (iter-defun my-iter (x)
(iter-yield (1+ (...
14
votes
3answers
416 views
Defun inside let with lexical binding gives byte-compile warning “the function is not known to be defined”
I want to get the effect of a static variable by using defun inside of let with lexical binding to create a closure. However, when byte-compiling the file, I get a warning. Am I doing something wrong, ...
0
votes
0answers
41 views
Bind a function-local variable to an asynchronous lambda [duplicate]
In wakatime-mode, there are a bunch of process calls that is done by the wakatime-call function. It calls a predefined shell command, so no real magic inside.
Now I’d like to make it a bit more error ...
6
votes
1answer
1k views
How to make local function binding for closure?
For example, when defining the natural number sequence stream, I can use
;; -*- lexical-binding: t; -*-
(defun nats (n)
(cons n (lambda () (nats (1+ n)))))
(nats 0)
=> (0 closure ((n . 0) ...
2
votes
1answer
158 views
lexical-binding only set at the buffer level?
According to this, it seems to say setting lexical-binding only happens at the individual buffer level, i.e. I could not do (setq lexical-binding t) in my init file and have it apply to all subsequent ...
