base/reader.lisp

   1 ;;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp; indent-tabs-mode: nil -*-
   2 ;;;
   3 ;;; --- Reader utils
   4 ;;;
   5
   6 (in-package :iolib.base)
   7
   8 ;; Reader macros
   9
  10 (defgeneric enable-reader-macro* (name))
  11
  12 (defgeneric disable-reader-macro* (name))
  13
  14 (defmacro enable-reader-macro (name)
  15   `(eval-when (:compile-toplevel)
  16      (enable-reader-macro* ,name)))
  17
  18 (defmacro disable-reader-macro (name)
  19   `(eval-when (:compile-toplevel)
  20      (disable-reader-macro* ,name)))
  21
  22 (defun save-old-readtable (symbol readtable)
  23   (setf (getf (symbol-plist symbol) 'old-readtable) readtable))
  24
  25 (defun get-old-readtable (symbol)
  26   (getf (symbol-plist symbol) 'old-readtable))
  27
  28 (defmethod enable-reader-macro* :before ((name symbol))
  29   (save-old-readtable name *readtable*)
  30   (setf *readtable* (copy-readtable)))
  31
  32 (defmethod disable-reader-macro* ((name symbol))
  33   (assert (readtablep (get-old-readtable name)))
  34   (setf *readtable* (get-old-readtable name))
  35   (save-old-readtable name nil))
  36
  37 (defmacro define-syntax (name &body body)
  38   `(defmethod enable-reader-macro* ((name (eql ',name)))
  39      ,@body))