feat: Add specify exit code

Author: jcs090218

docs/content/Development-API/_index.en.md

@@ -900,6 +900,31 @@ Report error/warning depends on strict flag.
 
 See option [--strict](https://emacs-eask.github.io/Getting-Started/Commands-and-options/#---strict).
 
+# 🚩 Exit Code
+
+## 🔍 Variable: eask--exit-code
+
+Exit code specification.
+
+## 🔍 Function: eask-exit-code (&optional `key`)
+
+Return the exit code by the key symbol in the variable `eask--exit-code`.
+
+```elisp
+(eask-exit-code 'misuse)  ; by symbol
+```
+
+## 🔍 Function: eask--exit (&optional `exit-code` &rest `_`)
+
+Send exit code.
+
+This will kill Emacs process.
+
+```elisp
+(eask--exit 2)        ; by number
+(eask--exit 'misuse)  ; by symbol
+```
+
 # 🚩 Error Handling
 
 ## 🔍 Variable: eask--ignore-error-p
@@ -947,12 +972,6 @@ Prevent Emacs from being killed and inhibit display error/warning messages.
   (error "Nothing happens!"))
 ```
 
-## 🔍 Function: eask--exit (&optional `exit-code` &rest `_`)
-
-Send exit code.
-
-This will kill Emacs process.
-
 # 🚩 File
 
 ## 🔍 Function: eask-package-files ()

docs/content/Development-API/_index.zh-tw.md

@@ -890,6 +890,31 @@ cat /.log/messages.log
 
 見選項 [--strict](https://emacs-eask.github.io/Getting-Started/Commands-and-options/#---strict).
 
+# 🚩 退出代碼
+
+## 🔍 變數: eask--exit-code
+
+退出代碼規格。
+
+## 🔍 函式: eask-exit-code (&optional `key`)
+
+以變數 `eask--exit-code` 中的關鍵符號回傳 exit code。
+
+```elisp
+(eask-exit-code 'misuse)  ; 按符號
+```
+
+## 🔍 函式: eask--exit (&optional `exit-code` &rest `_`)
+
+傳送退出代碼。
+
+這會結束 Emacs 程序。
+
+```elisp
+(eask--exit 2)        ; 按數字
+(eask--exit 'misuse)  ; 按符號
+```
+
 # 🚩 錯誤處理
 
 ## 🔍 變數: eask--ignore-error-p
@@ -937,12 +962,6 @@ cat /.log/messages.log
   (error "Nothing happens!"))
 ```
 
-## 🔍 函式: eask--exit (&optional `exit-code` &rest `_`)
-
-傳送退出代碼。
-
-這會結束 Emacs 程序。
-
 # 🚩 文件
 
 ## 🔍 函式: eask-package-files ()

lisp/_prepare.el

@@ -1721,6 +1721,25 @@ For arguments MSG and ARGS, please see function `eask-msg' for the detials."
 Argument ARGS are direct arguments for functions `eask-error' or `eask-warn'."
   (apply (if (eask-strict-p) #'eask-error #'eask-warn) args))
 
+;;
+;;; Exit Code
+
+(defconst eask--exit-code
+  `((success . 0)   ; Unused
+    (failure . 1)   ; Catchall for general errors
+    (misuse  . 2))
+  "Exit code specification.")
+
+(defun eask-exit-code (key)
+  "Return the exit code by KEY symbol."
+  (alist-get key eask--exit-code))
+
+(defun eask--exit (&optional exit-code &rest _)
+  "Kill Emacs with EXIT-CODE (default 1)."
+  (kill-emacs (or (cond ((numberp exit-code) exit-code)
+                        ((symbolp exit-code) (eask-exit-code exit-code)))
+                  (eask-exit-code 'failure))))
+
 ;;
 ;;; Error Handling
 
@@ -1745,10 +1764,6 @@ Argument ARGS are direct arguments for functions `eask-error' or `eask-warn'."
   (declare (indent 0) (debug t))
   `(eask-ignore-errors (eask--silent-error ,@body)))
 
-(defun eask--exit (&optional exit-code &rest _)
-  "Kill Emacs with EXIT-CODE (default 1)."
-  (kill-emacs (or exit-code 1)))
-
 (defun eask--trigger-error ()
   "Trigger error event."
   (when (and (not eask--ignore-error-p)
@@ -1887,12 +1902,10 @@ the exit code.  The default value `nil' will be replaced by `1'; therefore
 would send exit code of `1'."
   (let* ((command (eask-2str command))  ; convert to string
          (help-file (concat eask-lisp-root "help/" command))
-         ;; The default exit code is `1' since `eask-help' prints the help
+         ;; The default exit code is `2' since `eask-help' prints the help
          ;; message on user error 99% of the time.
-         ;;
-         ;; TODO: Later replace exit code `1' with readable symbol after
-         ;; the exit code has specified.
-         (print-or-exit-code (or print-or-exit-code 1)))
+         (print-or-exit-code (or print-or-exit-code
+                                 (eask-exit-code 'misuse))))
     (if (file-exists-p help-file)
         (with-temp-buffer
           (insert-file-contents help-file)