From: Guillermo J. Rozas <edu/mit/csail/zurich/gjr>
Date: Fri, 10 Feb 1989 22:13:50 +0000 (+0000)
Subject: Add #@ to read back hashed objects.
X-Git-Tag: 20090517-FFI~12277
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=fbff4faf979b6feee842fe0f45e52056d301478c;p=mit-scheme.git

Add #@ to read back hashed objects.
---

diff --git a/v7/src/runtime/parse.scm b/v7/src/runtime/parse.scm
index a7f20699c..37dd0b38f 100644
--- a/v7/src/runtime/parse.scm
+++ b/v7/src/runtime/parse.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/runtime/parse.scm,v 14.5 1988/10/15 17:19:10 cph Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/runtime/parse.scm,v 14.6 1989/02/10 22:13:50 jinx Exp $
 
 Copyright (c) 1988 Massachusetts Institute of Technology
 
@@ -129,7 +129,8 @@ MIT in each case. |#
 		("#\\" ,parse-object/char-quote)
 		(("#f" "#F") ,parse-object/false)
 		(("#t" "#T") ,parse-object/true)
-		("#!" ,parse-object/named-constant)))
+		("#!" ,parse-object/named-constant)
+		("#@" ,parse-object/unhash)))
     table))
 
 ;;;; Top Level
@@ -476,4 +477,15 @@ MIT in each case. |#
     (cdr (or (assq object-name named-objects)
 	     (parse-error "No object by this name" object-name)))))
 
-(define named-objects)
\ No newline at end of file
+(define named-objects)
+
+(define (parse-object/unhash)
+  (discard-char)
+  (let ((number (parse-object/dispatch)))
+    (if (not (integer? number))	(parse-error "Invalid unhash syntax" number)
+	(let ((object (object-unhash number)))
+	  ;; This knows that 0 is the hash of #f.
+	  (if (and (false? object) (not (zero? number)))
+	      (parse-error "Invalid hash number" number)
+	      ;; (list 'QUOTE object)
+	      object)))))
\ No newline at end of file