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Diffstat (limited to 'obj2str.scm')
-rw-r--r-- | obj2str.scm | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/obj2str.scm b/obj2str.scm new file mode 100644 index 0000000..19d8464 --- /dev/null +++ b/obj2str.scm @@ -0,0 +1,61 @@ +;;; "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))) |