| 1 | ; "trnscrpt.scm", transcript functions for Scheme. |
| 2 | ; Copyright (c) 1992, 1993, 1995 Aubrey Jaffer |
| 3 | ; |
| 4 | ;Permission to copy this software, to redistribute it, and to use it |
| 5 | ;for any purpose is granted, subject to the following restrictions and |
| 6 | ;understandings. |
| 7 | ; |
| 8 | ;1. Any copy made of this software must include this copyright notice |
| 9 | ;in full. |
| 10 | ; |
| 11 | ;2. I have made no warrantee or representation that the operation of |
| 12 | ;this software will be error-free, and I am under no obligation to |
| 13 | ;provide any services, by way of maintenance, update, or otherwise. |
| 14 | ; |
| 15 | ;3. In conjunction with products arising from the use of this |
| 16 | ;material, there shall be no use of my name in any advertising, |
| 17 | ;promotional, or sales literature without prior written consent in |
| 18 | ;each case. |
| 19 | |
| 20 | (define transcript:port #f) |
| 21 | |
| 22 | (define (transcript-on filename) |
| 23 | (set! transcript:port (open-output-file filename))) |
| 24 | |
| 25 | (define (transcript-off) |
| 26 | (if (output-port? transcript:port) |
| 27 | (close-output-port transcript:port)) |
| 28 | (set! transcript:port #f)) |
| 29 | |
| 30 | (define read-char |
| 31 | (let ((read-char read-char) (write-char write-char)) |
| 32 | (lambda opt |
| 33 | (let ((ans (apply read-char opt))) |
| 34 | (cond ((eof-object? ans)) |
| 35 | ((output-port? transcript:port) |
| 36 | (write-char ans transcript:port))) |
| 37 | ans)))) |
| 38 | |
| 39 | (define read |
| 40 | (let ((read read) (write write) (newline newline)) |
| 41 | (lambda opt |
| 42 | (let ((ans (apply read opt))) |
| 43 | (cond ((eof-object? ans)) |
| 44 | ((output-port? transcript:port) |
| 45 | (write ans transcript:port) |
| 46 | (if (eqv? #\newline (apply peek-char opt)) |
| 47 | (newline transcript:port)))) |
| 48 | ans)))) |
| 49 | |
| 50 | (define write-char |
| 51 | (let ((write-char write-char)) |
| 52 | (lambda (obj . opt) |
| 53 | (apply write-char obj opt) |
| 54 | (if (output-port? transcript:port) |
| 55 | (write-char obj transcript:port))))) |
| 56 | |
| 57 | (define write |
| 58 | (let ((write write)) |
| 59 | (lambda (obj . opt) |
| 60 | (apply write obj opt) |
| 61 | (if (output-port? transcript:port) |
| 62 | (write obj transcript:port))))) |
| 63 | |
| 64 | (define display |
| 65 | (let ((display display)) |
| 66 | (lambda (obj . opt) |
| 67 | (apply display obj opt) |
| 68 | (if (output-port? transcript:port) |
| 69 | (display obj transcript:port))))) |
| 70 | |
| 71 | (define newline |
| 72 | (let ((newline newline)) |
| 73 | (lambda opt |
| 74 | (apply newline opt) |
| 75 | (if (output-port? transcript:port) |
| 76 | (newline transcript:port))))) |