gistfile1.txt

$ clisp
  i i i i i i i       ooooo    o        ooooooo   ooooo   ooooo
  I I I I I I I      8     8   8           8     8     o  8    8
  I  \ `+' /  I      8         8           8     8        8    8
   \  `-+-'  /       8         8           8      ooooo   8oooo
    `-__|__-'        8         8           8           8  8
        |            8     o   8           8     o     8  8
  ------+------       ooooo    8oooooo  ooo8ooo   ooooo   8

Welcome to GNU CLISP 2.49 (2010-07-07) <http://clisp.cons.org/>

Copyright (c) Bruno Haible, Michael Stoll 1992, 1993
Copyright (c) Bruno Haible, Marcus Daniels 1994-1997
Copyright (c) Bruno Haible, Pierpaolo Bernardi, Sam Steingold 1998
Copyright (c) Bruno Haible, Sam Steingold 1999-2000
Copyright (c) Sam Steingold, Bruno Haible 2001-2010

Type :h and hit Enter for context help.

[1]> (load "line-oriented.lisp")
;; Loading file line-oriented.lisp ...
;; Loaded file line-oriented.lisp
T
[2]> 10 LET A = 0
(10 LET A = 0)
[3]> 20 PRINT A
(20 PRINT A)
[4]> 30 LET A = A + 1 
(30 LET A = A + 1)
[5]> 40 GOTO 20
(40 GOTO 20)
[6]> 

line-oriented.lisp

(in-package :user)

(let ((orig-rt (copy-readtable nil)))
  (dotimes (n 10)
    (set-macro-character
     (digit-char n)
     (lambda (stream char)
       (let ((*readtable* orig-rt))
         (values (list 'quote
                       (read-from-string
                        (concatenate 'string "(" (string char)
                                     (read-line stream) ")")))))))))