From 18b4292e4f3c56393ea6d6dd0249089c6a8e29c2 Mon Sep 17 00:00:00 2001
From: Justin Ethier <justin.ethier@gmail.com>
Date: Fri, 10 Feb 2017 23:13:42 +0000
Subject: [PATCH] Added with-handler

---
 scheme/base.sld               | 15 +++++++++++++++
 scripts/convert-doc-index.scm |  8 +++++++-
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/scheme/base.sld b/scheme/base.sld
index 87ee67ff..0a398879 100644
--- a/scheme/base.sld
+++ b/scheme/base.sld
@@ -119,6 +119,7 @@
     error
     raise
     raise-continuable
+    with-handler
     with-exception-handler
     Cyc-add-exception-handler
     Cyc-remove-exception-handler
@@ -976,6 +977,20 @@
     (define (raise-continuable obj)
       ((Cyc-current-exception-handler) 
         (cons 'continuable (if (pair? obj) obj (list obj)))))
+    ;; A simpler exception handler based on the one from Bigloo:
+    ;; https://www-sop.inria.fr/indes/fp/Bigloo/doc/bigloo-17.html#g20889
+    ;(define (with-handler handler body)
+    (define-syntax with-handler
+      (er-macro-transformer
+        (lambda (exp rename compare)
+          `(call/cc
+             (lambda (k)
+               (with-exception-handler
+                 (lambda (obj)
+                   (,(cadr exp) obj)
+                   (k #t))
+                 (lambda ()
+                   ,@(cddr exp))))))))
     (define (with-exception-handler handler thunk)
       (let ((result #f)
             (my-handler 
diff --git a/scripts/convert-doc-index.scm b/scripts/convert-doc-index.scm
index 500be569..20681295 100644
--- a/scripts/convert-doc-index.scm
+++ b/scripts/convert-doc-index.scm
@@ -46,7 +46,13 @@
 (define (loop)
  (let ((line (read-line)))
   (when (not (eof-object? line))
-    (call/cc
+    (with-handler
+      (lambda (obj)
+        (display `(Error processing line ,line details ,obj)))
+      (display (convert-line line))
+      (newline))
+        
+    #;(call/cc
       (lambda (k)
         (with-exception-handler
           (lambda (obj)