(in-package #:monparser)

(defun parse (parser data)
  (let* ((result (funcall parser
                          (make-instance 'parser-input
                                         :data data))))
    (if (parsing-p result)
      (let ((finished? (not (has-data? (parsing-left result)))))
        (values (parsing-tree result) finished?))
      result)))

(defun append-on-failure (p message)
  (lambda (input)
    (let ((result (funcall p input)))
      (if (failure-p result)
        (make-failure :place (failure-place result)
                      :message (concatenate 'string message (failure-message result))
                      :priority (failure-priority result))
        result))))

(defmacro defparser (name args parser)
  (let ((message (format nil "In ~a:~&" name)))
    (if (null args)
      `(defparameter ,name (append-on-failure ,parser ,message))
      `(defun ,name ,args (append-on-failure ,parser ,message)))))