simple_cdr_lambda_defun.el

;; To run:   M-x ielm RET
;; To run buffer:   M-x eval-buffer
;; To run ONE line;   M-x eval-region

;; **Position AFTER code; C-x C-e evaluates**

(+ 4 5)

emacs-version
buffer-file-name

;; function
(defun add-nums (+ a b) )
(add-nums 2 3)

;;  lambda
((lambda (number) (* number 7)) 3)


;; nreverse
(nreverse '(1 2 3 4))
(nreverse (1 2 3 4))   # error

(reverse abc)    # error


(def rac (lambda (abc) (car(nreverse abc)))  # OK
     rac(abc)  # error

(def rac (lambda (abc)) (car (reverse abc)))

;; load, import library
(require 'ert)

;; return logical
(equal 5 5)

;; if-then
(if (< 0 4) "yes" "no")

;; predicate; no space before p
(numberp 1.1)

(number p "a")


;; REGISTERS
;; set-register to open  a file (C-x C-3 AFTER code)
(set-register ?i (cons 'file "~/code/elisp_project/second"))


(set-register ?r (cons 'file "~/code/docs/tech_notes/310_R_notes.qmd")
(set-register ?z (cons 'file "~/code/elisp_project/second"))

(setq z "A")
(message "item %s" z)
;; (message "Item %s and %s" z t)


;; LOCAL VARIABLE
;; Create local variable
(defvar jim_var nil "Your documentation here.")

(set (make-local-variable 'jim_var) <the-value>)

;;  position AFTER )   C-x C-e
(buffer-file-name)

;; evaluates to itsef
'(5 6 "A")

;; 
?A

;; 10	
?\n

?C-c

;; ^c
(kbd "C-c")


;; list, self-evaluates to itself?
;; but a macro, would evaluate (??)
[1 2 (+ 1 2)]
[+ 2 (+ 1 2)]
(+ 2 (+ 1 2))