[2_19] Re-impl save-object and load-object by string-load and string-…

…save

TeXmacs/progs/kernel/boot/abbrevs.scm

@@ -70,12 +70,14 @@
   (symbol->keyword (string->symbol (string-append "%" (number->string x)))))
 
 (define-public (save-object file value)
-  (call-with-output-file (url-materialize file "") (lambda (port)
-    (let-temporarily (((*s7* 'print-length) 9223372036854775807)) (write value port)))))
+  (string-save
+    (let-temporarily (((*s7* 'print-length) 9223372036854775807))
+      (object->string value))
+    file))
 
 (define-public (load-object file)
-  (let ((r (call-with-input-file (url-materialize file "r") (lambda (port) (read port)))))
-        (if (eof-object? r) '() r)))
+  (with-input-from-string (string-load file)
+    (lambda () (read))))
 
 (define-public (persistent-ref dir key)
   (and (persistent-has? dir key)