SRFI 34 from Schematics

svn: r1056

collects/drscheme/acks.ss

@@ -47,17 +47,15 @@
   (define (get-translating-acks)
     (string-append
      "Thanks to "
+     "ChongKai Zhu, "
      "Ian Barland, "
      "Biep Durieux, "
      "Tim Hanson, "
      "Chihiro Kuraya, "
-     "Paulo Jorge Matos, "
      "Philippe Meunier, "
      "Jens Axel Søgaard, "
      "Francisco Solsona, "
      "Reini Urban, "
-     "Paolo Zoppetti, "
      "and "
-     "Zhu Chongkai "
+     "Paolo Zoppetti "
      "for their help translating DrScheme's GUI to other languages.")))
-  

collects/srfi/34.ss

@@ -0,0 +1,5 @@
+;; module loader for SRFI-34
+(module |34| mzscheme
+  (require (lib "exception.ss" "srfi" "34"))
+  (provide (all-from (lib "exception.ss" "srfi" "34"))
+           raise))

collects/srfi/34/exception.ss

@@ -0,0 +1,25 @@
+;; SRFI 34 for PLT Scheme
+;; Zhu Chongkai, April 2005
+;; <mrmathematica@yahoo.com>
+(module exception mzscheme
+  
+  (provide with-exception-handler
+           guard)
+  
+  (define-syntax with-exception-handler
+    (syntax-rules ()
+      ((_ handler thunk)
+       (with-handlers (((lambda (exn) #t) handler)) (thunk)))))
+  
+  (define-syntax guard
+    (syntax-rules (else)
+      ((_ (var clause ... (else de ...)) e1 e2 ...)
+       (with-handlers (((lambda (exn) #t)
+                        (lambda (var) (cond clause ...
+                                            (else de ...)))))
+         e1 e2 ...))
+      ((_ (var clause ...) e1 e2 ...)
+       (with-handlers (((lambda (exn) #t)
+                        (lambda (var) (cond clause ...
+                                            (else (raise var))))))
+         e1 e2 ...)))))