summaryrefslogtreecommitdiffstats
path: root/obj2str.scm
blob: 19d84649c17f009179ac8b67736d83d3cc9ec0bb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
;;; "obj2str.scm", write objects to a string.
;Copyright (C) 1993, 1994 Aubrey Jaffer
;
;Permission to copy this software, to redistribute it, and to use it
;for any purpose is granted, subject to the following restrictions and
;understandings.
;
;1.  Any copy made of this software must include this copyright notice
;in full.
;
;2.  I have made no warrantee or representation that the operation of
;this software will be error-free, and I am under no obligation to
;provide any services, by way of maintenance, update, or otherwise.
;
;3.  In conjunction with products arising from the use of this
;material, there shall be no use of my name in any advertising,
;promotional, or sales literature without prior written consent in
;each case.

(require 'string-port)

(define (object->string obj)
  (cond ((symbol? obj) (symbol->string obj))
	((number? obj) (number->string obj))
	(else
	 (call-with-output-string
	  (lambda (port) (write obj port))))))

; File: "obj2str.scm"   (c) 1991, Marc Feeley

;(require 'generic-write)

; (object->string obj) returns the textual representation of 'obj' as a
; string.
;
; Note: (write obj) = (display (object->string obj))

;(define (object->string obj)
;  (let ((result '()))
;    (generic-write obj #f #f (lambda (str) (set! result (cons str result)) #t))
;    (reverse-string-append result)))

; (object->limited-string obj limit) returns a string containing the first
; 'limit' characters of the textual representation of 'obj'.

(define (object->limited-string obj limit)
  (require 'generic-write)
  (let ((result '()) (left limit))
    (generic-write obj #f #f
		   (lambda (str)
		     (let ((len (string-length str)))
		       (if (> len left)
			   (begin
			     (set! result (cons (substring str 0 left) result))
			     (set! left 0)
			     #f)
			   (begin
			     (set! result (cons str result))
			     (set! left (- left len))
			     #t)))))
    (reverse-string-append result)))