Improve detection of XML in urweb-mode; small tutorial improvement

2 files changed, 17 insertions, 28 deletions

diff --git a/doc/intro.ur b/doc/intro.ur
index 02adfdd2..e3611567 100644
--- a/doc/intro.ur
+++ b/doc/intro.ur
@@ -259,20 +259,24 @@ signature STACK = sig
     con t :: Type -> Type
     val empty : a ::: Type -> t a
     val push : a ::: Type -> t a -> a -> t a
-    val pop : a ::: Type -> t a -> option a
+    val peek : a ::: Type -> t a -> option a
+    val pop : a ::: Type -> t a -> option (t a)
 end
 
 structure Stack : STACK = struct
     con t = list
     val empty [a] = []
     fun push [a] (t : t a) (x : a) = x :: t
+    fun peek [a] (t : t a) = case t of
+                                 [] => None
+                               | x :: _ => Some x
     fun pop [a] (t : t a) = case t of
-                                [] => None
-                              | x :: _ => Some x
+                                 [] => None
+                               | _ :: t' => Some t'
 end
 
 (* begin eval *)
-Stack.pop (Stack.push (Stack.push Stack.empty "A") "B")
+Stack.peek (Stack.push (Stack.push Stack.empty "A") "B")
 (* end *)
 
 (* Ur also inherits the ML concept of <b>functors</b>, which are functions from modules to modules. *)
diff --git a/src/elisp/urweb-mode.el b/src/elisp/urweb-mode.el
index c9fe5f19..c4cb3476 100644
--- a/src/elisp/urweb-mode.el
+++ b/src/elisp/urweb-mode.el
@@ -170,7 +170,7 @@ See doc for the variable `urweb-mode-info'."
           (finished nil)
           (answer nil)
           )
-      (while (and (not finished) (re-search-backward "[<>{}]" nil t))
+      (while (and (not finished) (re-search-backward "[<{}]" nil t))
         (cond
          ((looking-at "{")
           (if (> depth 0)
@@ -178,29 +178,14 @@ See doc for the variable `urweb-mode-info'."
             (setq finished t)))
          ((looking-at "}")
           (incf depth))
-         ((save-excursion (backward-char 1) (or (looking-at "=>")
-                                                (looking-at "->")
-                                                (looking-at "<>")))
-          nil)
-         ((or (looking-at "< ") (looking-at "<="))
-          nil)
-         ((looking-at "<")
-          (setq finished t))
-         ((save-excursion (backward-char 1) (looking-at " >"))
-          nil)
-         ((looking-at ">")
-          (cond
-           ((> depth 0)
-            (if (not (re-search-backward "<" nil t))
-                (setq finished t)))
-           ((save-excursion (backward-char 1) (looking-at " "))
-            (setq finished t))
-           (t
-            (progn (backward-char 4)
-                   (setq answer (not (or
-                                      (looking-at "/xml")
-                                      (looking-at "xml/"))))
-                   (setq finished t)))))))
+         ((looking-at "<xml>")
+          (if (> depth 0)
+              (decf depth)
+            (progn
+              (setq answer t)
+              (setq finished t))))
+         ((looking-at "</xml>")
+          (incf depth))))
       answer)))
 
 (defun amAttribute (face)