Common Lisp calculator, 2

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1. To run the following code, you have to install the Quicklisp library manager by following the steps in my blog post titled cmu-infix.

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2.1 To enable the library, in the Common Lisp REPL, run the code:

(ql:quickload :cmu-infix)

(named-readtables:in-readtable cmu-infix:syntax)

2.2 If you encounter the error message:

2.2.1 empty the cache folder:

~/.cache/common-lisp/

2.2.2 Restart the Common Lisp REPL.

2.2.3 Reload the library.

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3.1 The goal of the following code is to create our own REPL.

(defmacro infix-string-eval (a-string)
  `(eval (read-from-string
          (concatenate 'string
                       "#I (" ,a-string ")"))))

(defun read-repl-all ()
  (loop (print (write-to-string (read)))))

(defun my-repl ()
  (loop
    (let ((a-string (write-to-string (read))))
      (if (or (string-equal "(exit)" a-string)
              (string-equal "exit" a-string))
          (return)            
          (print
           (infix-string-eval
            (string-trim "|()" a-string))))))) 

3.2 In the Common Lisp REPL, run the code:

(my-repl)

— Me@2022-12-26 01:10:34 PM

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The symbol

^

is the bitwise exclusive OR.

To create an exponentiation, we use

^^

— Me@2023-09-09 12:51:46 PM

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— Me@2023-11-22 12:56:00 PM

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2023.11.23 Thursday (c) All rights reserved by ACHK