Function: OPEN-SCHEMA-TABLE

Source

(defun open-schema-table (pathname &key if-exists if-does-not-exist)
  ;; Load existing schemas from the file.
  (if (probe-file pathname)
      (ecase if-exists
        (:error (error "Schema table file ~S already exists." pathname))
        (:supersede
         ;; Create an empty schema table, save it and return it.
         (let ((table (make-instance 'schema-table :pathname pathname)))
           (save-schema-table table)
           table))
        (:overwrite
         ;; Normal case
         (let ((table (first (load-objects pathname))))
           (when (not (equal pathname (schema-table-pathname table)))
             ;; The table was moved; update the pathname info.
             (setf (schema-table-pathname table) pathname)
             (save-schema-table table))
           table)))
    (ecase if-does-not-exist
      (:error (error "Schema table file ~S does not exist." pathname))
      (:create
         ;; Create an empty schema table, save it and return it.
         (let ((table (make-instance 'schema-table :pathname pathname)))
           (save-schema-table table)
           table)))))