Added -e,--eval functionality (#2091)

* added -e,--eval functionality

* fixed to meet project coding standards

* added check for existence of --eval arg

Author: ethanxxxl

src/command-line-arguments.lisp

@@ -7,7 +7,8 @@ Options:
         --log-filename FILENAME   file name of the log file
         -i, --interface INTERFACE interface to use, either sdl2 or ncurses
         -v, --version             print the version number and exit
-        -h, --help                display this help and exit"
+        -h, --help                display this help and exit
+        -e, --eval FORM           common lisp form (in quotes) to evaluate on startup"
   "Help output for cli")
 
 (defun show-help ()
@@ -23,22 +24,26 @@ Options:
   (without-init-file nil)
   (log-filename nil)
   (interface nil)
-  (filenames '()))
+  (filenames '())
+  (eval-form-str nil))
 
-(defun use-spash-screen-p (args)
+(defun use-splash-screen-p (args)
   (null (command-line-arguments-filenames args)))
 
 (defun command-line-arguments-error (fmt &rest args)
   (error 'command-line-arguments-error :format-control fmt :format-arguments args))
 
 (defun parse-args (args)
+  "returns a `command-line-arguments` that represents the arguments passed in from `args`.
+`args` should be a list of strings (from `uiop:command-line-arguments`)."
   (let ((help nil)
         (debug nil)
         (version nil)
         (without-init-file nil)
         (log-filename nil)
         (interface nil)
-        (filenames '()))
+        (filenames '())
+        (eval-form-str nil))
     (loop :while args
           :for arg := (pop args)
           :do (cond ((member arg '("-h" "--help") :test #'equal)
@@ -60,6 +65,9 @@ Options:
                            (command-line-arguments-error "Please specify an interface to use."))))
                     ((member arg '("-v" "--version") :test #'equal)
                      (setf version t))
+                    ((member arg '("-e" "--eval") :test #'equal)
+                     ;; assumes that FORM follows --eval and is in quotes.
+                     (setf eval-form-str (pop args)))
                     ((or (stringp arg) (pathnamep arg))
                      (push arg filenames))
                     (t
@@ -70,12 +78,24 @@ Options:
                                  :without-init-file without-init-file
                                  :log-filename log-filename
                                  :interface interface
-                                 :filenames (nreverse filenames))))
+                                 :filenames (nreverse filenames)
+                                 :eval-form-str eval-form-str)))
 
 (defun apply-args (args)
   (declare (command-line-arguments args))
-  (if (and (use-spash-screen-p args)
+  
+  (if (and (use-splash-screen-p args)
            *splash-function*)
       (funcall *splash-function*)
       (loop :for filename :in (command-line-arguments-filenames args)
-            :do (uiop:symbol-call :lem :find-file (merge-pathnames filename (uiop:getcwd))))))
+            :do (uiop:symbol-call :lem :find-file (merge-pathnames filename (uiop:getcwd)))))
+
+  
+  (let (form-str form)
+    (setf form-str (command-line-arguments-eval-form-str args))
+    (when form-str 
+      (setf form (read-from-string form-str nil))
+    
+      (if form
+          (eval form)
+          (editor-error "WARNING: -e/--eval supplied, but no form was provided!")))))