feat(lxp): Add parser option to disable attribute positions

docs/manual.html

@@ -144,13 +144,16 @@ <h4>Finishing parsing</h4>
 <h4>Constructor</h4>
 
 <dl class="reference">
-	<dt><strong>lxp.new(<em>callbacks [, separator[, merge_character_data]]</em>)</strong></dt>
+	<dt><strong>lxp.new(<em>callbacks [, separator[, [merge_character_data, attribute_position]]]</em>)</strong></dt>
 	<dd>The parser is created by a call to the function <strong>lxp.new</strong>,
 	which returns the created parser or raises a Lua error. It
 	receives the callbacks table and optionally the parser <a href="#separator">
 	separator character</a> used in the namespace expanded element names.
 	If <em>merge_character_data</em> is false then LuaExpat will not combine multiple
-	CharacterData calls into one. For more info on this behaviour see CharacterData below.</dd>
+	CharacterData calls into one. For more info on this behaviour see CharacterData below.
+	If <em>attribute_position</em> is false then LuaExpat will not include the
+	attribute position in the attributes table. For more info on this behaviour see
+	StartElement below.</dd>
 </dl>
 
 <h4>Methods</h4>
@@ -424,7 +427,8 @@ <h4>Callbacks</h4>
 	every attribute in the element start tag and entries for the
 	default attributes for that element.<br/>
 	The attributes are listed by name (including the inherited ones)
-	and by position (inherited attributes are not considered in the
+	and, unless <em>attribute_position</em> is set to false when calling
+	<em>lxp.new()</em>, by position (inherited attributes are not considered in the
 	position list).<br/>
 	As an example if the <em>book</em> element has attributes
 	<em>author</em>, <em>title</em> and an optional <em>format</em>
@@ -434,8 +438,8 @@ <h4>Callbacks</h4>
 </pre>
     would be represented as<br/>
 <pre class="example">
-{[1] = "Ierusalimschy, Roberto",
- [2] = "Programming in Lua",
+{[1] = "author",
+ [2] = "title",
  author = "Ierusalimschy, Roberto",
  format = "printed",
  title = "Programming in Lua"}

src/lxplib.c

@@ -48,6 +48,7 @@ struct lxp_userdata {
   enum XPState state;
   luaL_Buffer *b;  /* to concatenate sequences of cdata pieces */
   int bufferCharData; /* whether to buffer cdata pieces */
+  int attributePosition; /* whether to include attribute position */
 };
 
 typedef struct lxp_userdata lxp_userdata;
@@ -201,7 +202,7 @@ static void f_DefaultExpand (void *ud, const char *data, int len) {
 static void f_StartElement (void *ud, const char *name, const char **attrs) {
   lxp_userdata *xpu = (lxp_userdata *)ud;
   lua_State *L = xpu->L;
-  int lastspec = XML_GetSpecifiedAttributeCount(xpu->parser) / 2;
+  int lastspec = xpu->attributePosition != 0 ? XML_GetSpecifiedAttributeCount(xpu->parser) / 2 : 0;
   int i = 1;
   if (getHandle(xpu, StartElementKey) == 0) return;  /* no handle */
   lua_pushstring(L, name);
@@ -546,9 +547,12 @@ static void checkcallbacks (lua_State *L) {
 
 static int lxp_make_parser (lua_State *L) {
   XML_Parser p;
+  int attributePosition = (lua_type(L, 4) != LUA_TBOOLEAN) || (lua_toboolean(L, 4) != 0);
   int bufferCharData = (lua_type(L, 3) != LUA_TBOOLEAN) || (lua_toboolean(L, 3) != 0);
   char sep = *luaL_optstring(L, 2, "");
   lxp_userdata *xpu = createlxp(L);
+  printf("lxp_make_parser: '%c' %d %d\n", sep, bufferCharData, attributePosition);
+  xpu->attributePosition = attributePosition;
   xpu->bufferCharData = bufferCharData;
   p = xpu->parser = (sep == '\0') ? XML_ParserCreate(NULL) :
                                     XML_ParserCreateNS(NULL, sep);