From 17ad2a3fd8933aa49bff4c8ea49963d15cc0db92 Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Thu, 14 Mar 2013 10:36:16 +0200
Subject: Add support for peeking and getting current event in XML parser

---
 cutl/xml/parser.cxx | 22 +++++++++++-----------
 cutl/xml/parser.hxx | 33 ++++++++++++++++++++++++++++++++-
 2 files changed, 43 insertions(+), 12 deletions(-)

(limited to 'cutl')

diff --git a/cutl/xml/parser.cxx b/cutl/xml/parser.cxx
index 24a91ee..5724794 100644
--- a/cutl/xml/parser.cxx
+++ b/cutl/xml/parser.cxx
@@ -54,7 +54,7 @@ namespace cutl
     parser::
     parser (istream& is, const string& name, feature_type f)
         : is_ (is), name_ (name), feature_ (f),
-          depth_ (0), event_ (eof), queue_ (eof),
+          depth_ (0), state_ (state_next), event_ (eof), queue_ (eof),
           pqname_ (&qname_), pvalue_ (&value_),
           attr_i_ (0), start_ns_i_ (0), end_ns_i_ (0)
     {
@@ -156,9 +156,9 @@ namespace cutl
     };
 
     parser::event_type parser::
-    next ()
+    next_ ()
     {
-      event_type e (next_ ());
+      event_type e (next_body ());
 
       // Content-specific processing. Note that we handle characters in the
       // characters_() Expat handler for two reasons. Firstly, it is faster
@@ -200,7 +200,7 @@ namespace cutl
     }
 
     parser::event_type parser::
-    next_ ()
+    next_body ()
     {
       // See if we have any start namespace declarations we need to return.
       //
@@ -230,7 +230,7 @@ namespace cutl
         default:
           {
             assert (false);
-            return eof;
+            return event_ = eof;
           }
         }
       }
@@ -276,7 +276,7 @@ namespace cutl
         default:
           {
             assert (false);
-            return eof;
+            return event_ = eof;
           }
         }
       }
@@ -316,9 +316,9 @@ namespace cutl
       //
       if (queue_ != eof)
       {
-        event_type r (queue_);
+        event_ = queue_;
         queue_ = eof;
-        return r;
+        return event_;
       }
 
       XML_ParsingStatus ps;
@@ -334,11 +334,11 @@ namespace cutl
       case XML_PARSING:
         {
           assert (false);
-          return eof;
+          return event_ = eof;
         }
       case XML_FINISHED:
         {
-          return eof;
+          return event_ = eof;
         }
       case XML_SUSPENDED:
         {
@@ -357,7 +357,7 @@ namespace cutl
               // unless this was the last chunk, in which case this is eof.
               //
               if (ps.finalBuffer)
-                return eof;
+                return event_ = eof;
 
               break;
             }
diff --git a/cutl/xml/parser.hxx b/cutl/xml/parser.hxx
index b61d26d..5dc2a83 100644
--- a/cutl/xml/parser.hxx
+++ b/cutl/xml/parser.hxx
@@ -106,7 +106,34 @@ namespace cutl
       };
 
       event_type
-      next ();
+      next ()
+      {
+        if (state_ == state_next)
+          return next_ ();
+        else
+        {
+          state_ = state_next;
+          return event_;
+        }
+      }
+
+      event_type
+      peek ()
+      {
+        if (state_ == state_peek)
+          return event_;
+        else
+        {
+          state_ = state_peek;
+          return next_ ();
+        }
+      }
+
+      // Return the even that was last returned by the call to next() or
+      // peek().
+      //
+      event_type
+      event () {return event_;}
 
       const qname_type& qname () const {return *pqname_;}
 
@@ -167,6 +194,9 @@ namespace cutl
       event_type
       next_ ();
 
+      event_type
+      next_body ();
+
       void
       handle_error ();
 
@@ -177,6 +207,7 @@ namespace cutl
 
       XML_Parser p_;
       std::size_t depth_;
+      enum {state_next, state_peek} state_;
       event_type event_;
       event_type queue_;
 
-- 
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