From e8463d700589fed1301aff8fdd4762b61727f86f Mon Sep 17 00:00:00 2001
From: mainzelm <mainzelm>
Date: Mon, 16 Sep 2002 16:16:04 +0000
Subject: [PATCH] Turn error hierarchie upside down.

---
 scheme/lib/dns.scm | 44 ++++++++++++++++++++++----------------------
 1 file changed, 22 insertions(+), 22 deletions(-)

diff --git a/scheme/lib/dns.scm b/scheme/lib/dns.scm
index a0fcfe8..14f811f 100644
--- a/scheme/lib/dns.scm
+++ b/scheme/lib/dns.scm
@@ -90,56 +90,56 @@
 
 
 ;; --- error conditions
-(define-condition-type 'invalid-type '())
+
+;; supertype of all errors signaled by this library
+(define-condition-type 'dns-error '(error))
+(define dns-error? (condition-predicate 'dns-error))
+
+(define-condition-type 'invalid-type '(dns-error))
 (define invalid-type? (condition-predicate 'invalid-type))
 
-(define-condition-type 'invalid-class '())
+(define-condition-type 'invalid-class '(dns-error))
 (define invalid-class? (condition-predicate 'invalid-class))
 
-(define-condition-type 'parse-error '())
+(define-condition-type 'parse-error '(dns-error))
 (define parse-error? (condition-predicate 'parse))
 
-(define-condition-type 'unexpected-eof-from-server '())
+(define-condition-type 'unexpected-eof-from-server '(dns-error))
 (define unexpected-eof-from-server? (condition-predicate 'unexpected-eof-from-server))
 
-(define-condition-type 'bad-address '())
+(define-condition-type 'bad-address '(dns-error))
 (define bad-address? (condition-predicate 'bad-address))
 
-(define-condition-type 'no-nameservers '())
+(define-condition-type 'no-nameservers '(dns-error))
 (define no-nameservers? (condition-predicate 'no-nameservers))
 
-(define-condition-type 'not-a-hostname '())
+(define-condition-type 'not-a-hostname '(dns-error))
 (define not-a-hostname? (condition-predicate 'not-a-hostname))
 
-(define-condition-type 'not-a-ip '())
+(define-condition-type 'not-a-ip '(dns-error))
 (define not-a-ip? (condition-predicate 'not-a-ip))
 
+;; supertype of all errors signaled if the dns server returned a non-sero
+;; reply code
+(define-condition-type 'dns-server-error '(dns-error))
+(define dns-server-error? (condition-predicate 'dns-server-error))
 
-(define-condition-type 'dns-format-error '())
+(define-condition-type 'dns-format-error '(dns-server-error))
 (define dns-format-error? (condition-predicate 'dns-format-error))
 
-(define-condition-type 'dns-server-failure '())
+(define-condition-type 'dns-server-failure '(dns-server-error))
 (define dns-server-failure? (condition-predicate 'dns-server-failure))
 
-(define-condition-type 'dns-name-error '())
+(define-condition-type 'dns-name-error '(dns-server-error))
 (define dns-name-error? (condition-predicate 'dns-name-error))
 
-(define-condition-type 'dns-not-implemented '())
+(define-condition-type 'dns-not-implemented '(dns-server-error))
 (define dns-not-implemented? (condition-predicate 'dns-not-implemented))
 
-(define-condition-type 'dns-refused '())
+(define-condition-type 'dns-refused '(dns-server-error))
 (define dns-refused? (condition-predicate 'dns-refused))
 
 
-(define-condition-type 'dns-error '(dns-format-error
-				    dns-server-failure
-				    dns-name-error
-				    dns-not-implemented
-				    dns-refused))
-
-(define dns-error? (condition-predicate 'dns-error))
-
-
 ;; called by the error-handlers, prints out error descriptions
 (define (dns-error-messages condition more)
   (display "dns-error: ")