Add yxml_symlen() utility function

test/test.c

diff --git a/test/test.c b/test/test.c
index 065196b..18473bd 100644
--- a/test/test.c
+++ b/test/test.c
@@ -23,6 +23,7 @@
 #include <yxml.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <inttypes.h>
 
 
@@ -57,6 +58,7 @@
 static void y_printres(yxml_t *x, yxml_ret_t r) {
 	static int indata;
 	int nextdata = 0;
+
 	switch(r) {
 	case YXML_OK:
 		if(verbose) {
@@ -68,6 +70,8 @@
 	case YXML_ELEMSTART:
 		y_printtoken(x, "elemstart ");
 		y_printstring(x->elem);
+		if(yxml_symlen(x, x->elem) != strlen(x->elem))
+			y_printtoken(x, "assertfail: elem lengths don't match");
 		if(r & YXML_CONTENT)
 			y_printtoken(x, "content");
 		break;
@@ -77,6 +81,8 @@
 	case YXML_ATTRSTART:
 		y_printtoken(x, "attrstart ");
 		y_printstring(x->attr);
+		if(yxml_symlen(x, x->attr) != strlen(x->attr))
+			y_printtoken(x, "assertfail: attr lengths don't match");
 		break;
 	case YXML_ATTREND:
 		y_printtoken(x, "attrend");
@@ -92,6 +98,8 @@
 	case YXML_PISTART:
 		y_printtoken(x, "pistart ");
 		y_printstring(x->pi);
+		if(yxml_symlen(x, x->pi) != strlen(x->pi))
+			y_printtoken(x, "assertfail: pi lengths don't match");
 		break;
 	case YXML_PIEND:
 		y_printtoken(x, "piend");

yxml.h

diff --git a/yxml.h b/yxml.h
index 97c4bc8..97565ec 100644
--- a/yxml.h
+++ b/yxml.h
@@ -143,6 +143,16 @@
 #endif
 
 
+/* Returns the length of the element name (x->elem), attribute name (x->attr),
+ * or PI name (x->pi). This function should ONLY be used directly after the
+ * YXML_ELEMSTART, YXML_ATTRSTART or YXML_PISTART (respectively) tokens have
+ * been returned by yxml_parse(), calling this at any other time may not give
+ * the correct results. This function should also NOT be used on strings other
+ * than x->elem, x->attr or x->pi. */
+static inline size_t yxml_symlen(yxml_t *x, const char *s) {
+	return (x->stack + x->stacklen) - (const unsigned char*)s;
+}
+
 #endif
 
 /* vim: set noet sw=4 ts=4: */

yxml.pod

diff --git a/yxml.pod b/yxml.pod
index bb4c6ea..bf5e172 100644
--- a/yxml.pod
+++ b/yxml.pod
@@ -241,7 +241,7 @@
 C<YXML_ELEMCLOSE>.
 
 Yxml will verify that elements properly nest and that the name of each closing
-tag properly matches that of the respective opening tag. The application may
+tag properly matches that of the corresponding opening tag. The application may
 safely assume that each C<YXML_ELEMSTART> is properly matched with a
 C<YXML_ELEMCLOSE>, or that otherwise an error is returned. Furthermore, only a
 single root element is allowed. When the root element is closed, no further
@@ -435,3 +435,16 @@
 "C<< <a/><!-- .. >>").
 
 =back
+
+=head2 Utility functions
+
+  size_t yxml_symlen(yxml_t *, const char *);
+
+C<yxml_symlen()> returns the length of the element name (C<< x->elem >>),
+attribute name (C<< x->attr >>), or PI name (C<< x->pi >>). When used
+correctly, it gives the same result as C<strlen()>, except without having to
+scan through the string. This function should B<ONLY> be used directly after
+the C<YXML_ELEMSTART>, C<YXML_ATTRSTART> or C<YXML_PISTART> (respectively)
+tokens have been returned by C<yxml_parse()>, calling this function at any
+other time may not give the correct results. This function should B<NOT> be
+used on strings other than C<< x->elem >>, C<< x->attr >> or C<< x->pi >>.