# HG changeset patch
# User Adam Chlipala <adam@chlipala.net>
# Date 1310770558 14400
# Node ID 8c32c7191bf04e3aa5d9450524c723d430b1c5e0
# Parent  0b639858200b029624872f0e580be9ddfb7a6ba6
Make 'static' protocol handle unlimited retry

diff -r 0b639858200b -r 8c32c7191bf0 doc/intro.ur
--- a/doc/intro.ur	Fri Jul 15 18:45:03 2011 -0400
+++ b/doc/intro.ur	Fri Jul 15 18:55:58 2011 -0400
@@ -73,3 +73,22 @@
 (* begin eval *)
 compose inc inc 3
 (* end *)
+
+(* The "option" type family is like ML's "option" or Haskell's "maybe."  Note that, while Ur follows most syntactic conventions of ML, one key difference is that type families appear before their arguments, as in Haskell. *)
+
+fun predecessor (n : int) : option int = if n >= 1 then Some (n - 1) else None
+
+(* begin hide *)
+fun show_option [t] (_ : show t) : show (option t) =
+    mkShow (fn x => case x of
+                        None => "None"
+                      | Some x => "Some(" ^ show x ^ ")")
+(* end *)
+
+(* begin eval *)
+predecessor 6
+(* end *)
+
+(* begin eval *)
+predecessor 0
+(* end *)
diff -r 0b639858200b -r 8c32c7191bf0 src/c/static.c
--- a/src/c/static.c	Fri Jul 15 18:45:03 2011 -0400
+++ b/src/c/static.c	Fri Jul 15 18:55:58 2011 -0400
@@ -25,15 +25,18 @@
  
   ctx = uw_init(0, NULL, log_debug);
   uw_set_app(ctx, &uw_application);
-  fk = uw_begin(ctx, argv[1]);
 
-  if (fk == SUCCESS) {
-    uw_print(ctx, 1);
-    puts("");
-    return 0;
-  } else {
-    fprintf(stderr, "Error!\n");
-    return 1;
+  while (1) {
+    fk = uw_begin(ctx, argv[1]);
+
+    if (fk == SUCCESS) {
+      uw_print(ctx, 1);
+      puts("");
+      return 0;
+    } else if (fk != UNLIMITED_RETRY) {
+      fprintf(stderr, "Error: %s\n", uw_error_message(ctx));
+      return 1;
+    }
   }
 }
 
diff -r 0b639858200b -r 8c32c7191bf0 src/tutorial.sml
--- a/src/tutorial.sml	Fri Jul 15 18:45:03 2011 -0400
+++ b/src/tutorial.sml	Fri Jul 15 18:55:58 2011 -0400
@@ -79,7 +79,7 @@
                 else
                     let
                         val (befor', after) = Substring.position " </span><span class=\"comment-delimiter\">*)</span>"
-                                                             (Substring.slice (after, 64, NONE))
+                                                                 (Substring.slice (after, 64, NONE))
                     in
                         if Substring.isEmpty after then
                             TextIO.outputSubstr (outf, source)