XPath: Added xpath_query::return_type() function, fixed evaluate_node_set documentation

git-svn-id: http://pugixml.googlecode.com/svn/trunk@232 99668b35-9821-0410-8761-19e4c4f06640

2 files changed, 91 insertions, 76 deletions

diff --git a/src/pugixml.hpp b/src/pugixml.hpp
index 4fba668..4c447dc 100644
--- a/src/pugixml.hpp
+++ b/src/pugixml.hpp
@@ -258,6 +258,16 @@ namespace pugi
 	class xpath_ast_node;

 	class xpath_allocator;

 	

+	/// XPath query return type classification

+	enum xpath_type_t

+	{

+		xpath_type_none,      ///< Unknown type (query failed to compile)

+		xpath_type_node_set,  ///< Node set (\see xpath_node_set)

+		xpath_type_number,    ///< Number

+		xpath_type_string,    ///< String

+		xpath_type_boolean    ///< Boolean

+	};

+

 	/**

 	 * A class that holds compiled XPath query and allows to evaluate query result

 	 */

@@ -286,6 +296,13 @@ namespace pugi
 		 * Dtor

 		 */

 		~xpath_query();

+

+		/**

+		 * Get query expression return type

+		 *

+		 * \return expression return type

+		 **/

+		xpath_type_t return_type() const;

 		

 		/**

 		 * Evaluate expression as boolean value for the context node \a n.

@@ -322,7 +339,7 @@ namespace pugi
 		

 		/**

 		 * Evaluate expression as node set for the context node \a n.

-		 * If expression does not directly evaluate to node set, function returns empty node set.

+		 * If expression does not directly evaluate to node set, throws xpath_exception.

 		 * Throws std::bad_alloc on out of memory error.

 		 *

 		 * \param n - context node

diff --git a/src/pugixpath.cpp b/src/pugixpath.cpp
index dabaedc..30dc3af 100644
--- a/src/pugixpath.cpp
+++ b/src/pugixpath.cpp
@@ -1214,15 +1214,6 @@ namespace pugi
 		ast_step_root					// select root node

 	};

 

-	enum ast_rettype_t

-	{

-		ast_type_none,

-		ast_type_node_set,

-		ast_type_number,

-		ast_type_string,

-		ast_type_boolean

-	};

-

 	enum axis_t

 	{

 		axis_ancestor,

@@ -1265,7 +1256,7 @@ namespace pugi
 	private:

 		ast_type_t m_type;

 		

-		ast_rettype_t m_rettype;

+		xpath_type_t m_rettype;

 

 		// tree node structure

 		xpath_ast_node* m_left;

@@ -1289,16 +1280,16 @@ namespace pugi
 		{

 			static bool run(xpath_ast_node* lhs, xpath_ast_node* rhs, xpath_context& c)

 			{

-				if (lhs->rettype() != ast_type_node_set && rhs->rettype() != ast_type_node_set)

+				if (lhs->rettype() != xpath_type_node_set && rhs->rettype() != xpath_type_node_set)

 				{

-					if (lhs->rettype() == ast_type_boolean || rhs->rettype() == ast_type_boolean)

+					if (lhs->rettype() == xpath_type_boolean || rhs->rettype() == xpath_type_boolean)

 						return Cbool()(lhs->eval_boolean(c), rhs->eval_boolean(c));

-					else if (lhs->rettype() == ast_type_number || rhs->rettype() == ast_type_number)

+					else if (lhs->rettype() == xpath_type_number || rhs->rettype() == xpath_type_number)

 						return Cdouble()(lhs->eval_number(c), rhs->eval_number(c));

-					else if (lhs->rettype() == ast_type_string || rhs->rettype() == ast_type_string)

+					else if (lhs->rettype() == xpath_type_string || rhs->rettype() == xpath_type_string)

 						return Cstring()(lhs->eval_string(c), rhs->eval_string(c));

 				}

-				else if (lhs->rettype() == ast_type_node_set && rhs->rettype() == ast_type_node_set)

+				else if (lhs->rettype() == xpath_type_node_set && rhs->rettype() == xpath_type_node_set)

 				{

 					xpath_node_set ls = lhs->eval_node_set(c);

 					xpath_node_set rs = rhs->eval_node_set(c);

@@ -1312,11 +1303,11 @@ namespace pugi
 					

 					return false;

 				}

-				else if (lhs->rettype() != ast_type_node_set && rhs->rettype() == ast_type_node_set)

+				else if (lhs->rettype() != xpath_type_node_set && rhs->rettype() == xpath_type_node_set)

 				{

-					if (lhs->rettype() == ast_type_boolean)

+					if (lhs->rettype() == xpath_type_boolean)

 						return Cbool()(lhs->eval_boolean(c), rhs->eval_boolean(c));

-					else if (lhs->rettype() == ast_type_number)

+					else if (lhs->rettype() == xpath_type_number)

 					{

 						double l = lhs->eval_number(c);

 						xpath_node_set rs = rhs->eval_node_set(c);

@@ -1329,7 +1320,7 @@ namespace pugi
 						

 						return false;

 					}

-					else if (lhs->rettype() == ast_type_string)

+					else if (lhs->rettype() == xpath_type_string)

 					{

 						std::string l = lhs->eval_string(c);

 						xpath_node_set rs = rhs->eval_node_set(c);

@@ -1343,11 +1334,11 @@ namespace pugi
 						return false;

 					}

 				}

-				else if (lhs->rettype() == ast_type_node_set && rhs->rettype() != ast_type_node_set)

+				else if (lhs->rettype() == xpath_type_node_set && rhs->rettype() != xpath_type_node_set)

 				{

-					if (rhs->rettype() == ast_type_boolean)

+					if (rhs->rettype() == xpath_type_boolean)

 						return Cbool()(lhs->eval_boolean(c), rhs->eval_boolean(c));

-					else if (rhs->rettype() == ast_type_number)

+					else if (rhs->rettype() == xpath_type_number)

 					{

 						xpath_node_set ls = lhs->eval_node_set(c);

 						double r = rhs->eval_number(c);

@@ -1360,7 +1351,7 @@ namespace pugi
 						

 						return false;

 					}

-					else if (rhs->rettype() == ast_type_string)

+					else if (rhs->rettype() == xpath_type_string)

 					{

 						xpath_node_set ls = lhs->eval_node_set(c);

 						std::string r = rhs->eval_string(c);

@@ -1384,9 +1375,9 @@ namespace pugi
 		{

 			static bool run(xpath_ast_node* lhs, xpath_ast_node* rhs, xpath_context& c)

 			{

-				if (lhs->rettype() != ast_type_node_set && rhs->rettype() != ast_type_node_set)

+				if (lhs->rettype() != xpath_type_node_set && rhs->rettype() != xpath_type_node_set)

 					return Cdouble()(lhs->eval_number(c), rhs->eval_number(c));

-				else if (lhs->rettype() == ast_type_node_set && rhs->rettype() == ast_type_node_set)

+				else if (lhs->rettype() == xpath_type_node_set && rhs->rettype() == xpath_type_node_set)

 				{

 					xpath_node_set ls = lhs->eval_node_set(c);

 					xpath_node_set rs = rhs->eval_node_set(c);

@@ -1404,7 +1395,7 @@ namespace pugi
 					

 					return false;

 				}

-				else if (lhs->rettype() != ast_type_node_set && rhs->rettype() == ast_type_node_set)

+				else if (lhs->rettype() != xpath_type_node_set && rhs->rettype() == xpath_type_node_set)

 				{

 					double l = lhs->eval_number(c);

 					xpath_node_set rs = rhs->eval_node_set(c);

@@ -1417,7 +1408,7 @@ namespace pugi
 					

 					return false;

 				}

-				else if (lhs->rettype() == ast_type_node_set && rhs->rettype() != ast_type_node_set)

+				else if (lhs->rettype() == xpath_type_node_set && rhs->rettype() != xpath_type_node_set)

 				{

 					xpath_node_set ls = lhs->eval_node_set(c);

 					double r = rhs->eval_number(c);

@@ -1455,7 +1446,7 @@ namespace pugi
 				c.position = i + 1;

 				c.size = size;

 				

-				if (expr->rettype() == ast_type_number)

+				if (expr->rettype() == xpath_type_number)

 				{

 					if (expr->eval_number(c) == i + 1)

 						*last++ = *it;

@@ -1911,24 +1902,24 @@ namespace pugi
 		}

 	public:

 		xpath_ast_node(ast_type_t type, const char* contents, xpath_allocator& a): m_type(type),

-			m_rettype(ast_type_none), m_left(0), m_right(0), m_third(0), m_next(0), m_contents(0)

+			m_rettype(xpath_type_none), m_left(0), m_right(0), m_third(0), m_next(0), m_contents(0)

 		{

 			set_contents(contents, a);

 		}

 		

 		xpath_ast_node(ast_type_t type, xpath_ast_node* left, xpath_ast_node* right, axis_t axis): m_type(type),

-			m_rettype(ast_type_none), m_left(left), m_right(right), m_third(0), m_next(0), m_contents(0),

+			m_rettype(xpath_type_none), m_left(left), m_right(right), m_third(0), m_next(0), m_contents(0),

 			m_axis(axis)

 		{

 		}

 

 		xpath_ast_node(ast_type_t type, xpath_ast_node* left = 0, xpath_ast_node* right = 0, xpath_ast_node* third = 0): m_type(type),

-			m_rettype(ast_type_none), m_left(left), m_right(right), m_third(third), m_next(0), m_contents(0)

+			m_rettype(xpath_type_none), m_left(left), m_right(right), m_third(third), m_next(0), m_contents(0)

 		{

 		}

 

 		xpath_ast_node(ast_type_t type, xpath_ast_node* left, axis_t axis, nodetest_t test, const char* contents, xpath_allocator& a):

-			m_type(type), m_rettype(ast_type_none), m_left(left), m_right(0), m_third(0), m_next(0),

+			m_type(type), m_rettype(xpath_type_none), m_left(left), m_right(0), m_third(0), m_next(0),

 			m_contents(0), m_axis(axis), m_test(test)

 		{

 			set_contents(contents, a);

@@ -2029,13 +2020,13 @@ namespace pugi
 			{

 				switch (m_rettype)

 				{

-				case ast_type_number:

+				case xpath_type_number:

 					return convert_number_to_boolean(eval_number(c));

 					

-				case ast_type_string:

+				case xpath_type_string:

 					return !eval_string(c).empty();

 					

-				case ast_type_node_set:				

+				case xpath_type_node_set:				

 					return !eval_node_set(c).empty();

 					

 				default:

@@ -2126,13 +2117,13 @@ namespace pugi
 			{

 				switch (m_rettype)

 				{

-				case ast_type_boolean:

+				case xpath_type_boolean:

 					return eval_boolean(c) ? 1 : 0;

 					

-				case ast_type_string:

+				case xpath_type_string:

 					return convert_string_to_number(eval_string(c).c_str());

 					

-				case ast_type_node_set:

+				case xpath_type_node_set:

 					return convert_string_to_number(eval_string(c).c_str());

 					

 				default:

@@ -2326,13 +2317,13 @@ namespace pugi
 			{

 				switch (m_rettype)

 				{

-				case ast_type_boolean:

+				case xpath_type_boolean:

 					return eval_boolean(c) ? "true" : "false";

 					

-				case ast_type_number:

+				case xpath_type_number:

 					return convert_number_to_string(eval_number(c));

 					

-				case ast_type_node_set:

+				case xpath_type_node_set:

 				{

 					xpath_node_set ns = eval_node_set(c);

 					return ns.empty() ? std::string("") : string_value(ns.first());

@@ -2383,7 +2374,7 @@ namespace pugi
 					c.position = i + 1;

 					c.size = set.size();

 				

-					if (m_right->rettype() == ast_type_number)

+					if (m_right->rettype() == xpath_type_number)

 					{

 						if (m_right->eval_number(c) == i + 1)

 							*last++ = *it;

@@ -2625,7 +2616,7 @@ namespace pugi
 			case ast_op_greater_or_equal:

 				m_left->check_semantics();

 				m_right->check_semantics();

-				m_rettype = ast_type_boolean;

+				m_rettype = xpath_type_boolean;

 				break;

 				

 			case ast_op_add:

@@ -2635,65 +2626,65 @@ namespace pugi
 			case ast_op_mod:

 				m_left->check_semantics();

 				m_right->check_semantics();

-				m_rettype = ast_type_number;

+				m_rettype = xpath_type_number;

 				break;

 				

 			case ast_op_negate:

 				m_left->check_semantics();

-				m_rettype = ast_type_number;

+				m_rettype = xpath_type_number;

 				break;

 			

 			case ast_op_union:

 				m_left->check_semantics();

 				m_right->check_semantics();

-				if (m_left->rettype() != ast_type_node_set || m_right->rettype() != ast_type_node_set)

+				if (m_left->rettype() != xpath_type_node_set || m_right->rettype() != xpath_type_node_set)

 					throw xpath_exception("Semantics error: union operator has to be applied to node sets");

-				m_rettype = ast_type_node_set;

+				m_rettype = xpath_type_node_set;

 				break;

 			

 			case ast_filter:

 			case ast_filter_posinv:

 				m_left->check_semantics();

 				m_right->check_semantics();

-				if (m_left->rettype() != ast_type_node_set)

+				if (m_left->rettype() != xpath_type_node_set)

 					throw xpath_exception("Semantics error: predicate has to be applied to node set");

-				m_rettype = ast_type_node_set;

+				m_rettype = xpath_type_node_set;

 				

-				if (!m_right->contains(ast_func_position) && m_right->rettype() != ast_type_number)

+				if (!m_right->contains(ast_func_position) && m_right->rettype() != xpath_type_number)

 					m_type = ast_filter_posinv;

 				break;

 			

 			case ast_predicate:

 				m_left->check_semantics();

-				m_rettype = ast_type_node_set;

+				m_rettype = xpath_type_node_set;

 				break;

 

 			case ast_variable:

 				throw xpath_exception("Semantics error: variable are not supported");

 				

 			case ast_string_constant:

-				m_rettype = ast_type_string;

+				m_rettype = xpath_type_string;

 				break;

 				

 			case ast_number_constant:

-				m_rettype = ast_type_number;

+				m_rettype = xpath_type_number;

 				break;

 				

 			case ast_func_last:

 			case ast_func_position:

-				m_rettype = ast_type_number;

+				m_rettype = xpath_type_number;

 				break;

 		

 			case ast_func_count:

 				m_left->check_semantics();

-				if (m_left->rettype() != ast_type_node_set)

+				if (m_left->rettype() != xpath_type_node_set)

 					throw xpath_exception("Semantics error: count() has to be applied to node set");

-				m_rettype = ast_type_number;

+				m_rettype = xpath_type_number;

 				break;

 				

 			case ast_func_id:

 				m_left->check_semantics();

-				m_rettype = ast_type_node_set;

+				m_rettype = xpath_type_node_set;

 				break;

 				

 			case ast_func_local_name_0:

@@ -2705,16 +2696,16 @@ namespace pugi
 				if (m_left)

 				{

 					m_left->check_semantics();

-					if (m_left->rettype() != ast_type_node_set)

+					if (m_left->rettype() != xpath_type_node_set)

 						throw xpath_exception("Semantics error: function has to be applied to node set");

 				}

-				m_rettype = ast_type_string;

+				m_rettype = xpath_type_string;

 				break;

 				

 			case ast_func_string_0:

 			case ast_func_string_1:

 				if (m_left) m_left->check_semantics();

-				m_rettype = ast_type_string;

+				m_rettype = xpath_type_string;

 				break;

 				

 			case ast_func_concat:

@@ -2724,7 +2715,7 @@ namespace pugi
 				for (xpath_ast_node* n = m_right; n; n = n->m_next)

 					n->check_semantics();

 					

-				m_rettype = ast_type_string;

+				m_rettype = xpath_type_string;

 				break;

 			}

 			

@@ -2732,7 +2723,7 @@ namespace pugi
 			case ast_func_contains:

 				m_left->check_semantics();

 				m_right->check_semantics();

-				m_rettype = ast_type_boolean;

+				m_rettype = xpath_type_boolean;

 				break;

 				

 			case ast_func_substring_before:

@@ -2742,13 +2733,13 @@ namespace pugi
 				m_left->check_semantics();

 				m_right->check_semantics();

 				if (m_third) m_third->check_semantics();

-				m_rettype = ast_type_string;

+				m_rettype = xpath_type_string;

 				break;

 		

 			case ast_func_string_length_0:

 			case ast_func_string_length_1:

 				if (m_left) m_left->check_semantics();

-				m_rettype = ast_type_number;

+				m_rettype = xpath_type_number;

 				break;

 				

 			case ast_func_normalize_space_0:

@@ -2757,7 +2748,7 @@ namespace pugi
 				if (m_left) m_left->check_semantics();

 				if (m_right) m_right->check_semantics();

 				if (m_third) m_third->check_semantics();

-				m_rettype = ast_type_string;

+				m_rettype = xpath_type_string;

 				break;

 		

 			case ast_func_boolean:

@@ -2766,27 +2757,27 @@ namespace pugi
 			case ast_func_false:

 			case ast_func_lang:

 				if (m_left) m_left->check_semantics();

-				m_rettype = ast_type_boolean;

+				m_rettype = xpath_type_boolean;

 				break;

 			

 			case ast_func_number_0:

 			case ast_func_number_1:

 				if (m_left) m_left->check_semantics();

-				m_rettype = ast_type_number;

+				m_rettype = xpath_type_number;

 				break;

 		

 			case ast_func_sum:

 				m_left->check_semantics();

-				if (m_left->rettype() != ast_type_node_set)

+				if (m_left->rettype() != xpath_type_node_set)

 					throw xpath_exception("Semantics error: sum() has to be applied to node set");

-				m_rettype = ast_type_number;

+				m_rettype = xpath_type_number;

 				break;

 				

 			case ast_func_floor:

 			case ast_func_ceiling:

 			case ast_func_round:

 				if (m_left) m_left->check_semantics();

-				m_rettype = ast_type_number;

+				m_rettype = xpath_type_number;

 				break;

 

 			case ast_step:

@@ -2794,19 +2785,19 @@ namespace pugi
 				if (m_left)

 				{

 					m_left->check_semantics();

-					if (m_left->rettype() != ast_type_node_set)

+					if (m_left->rettype() != xpath_type_node_set)

 						throw xpath_exception("Semantics error: step has to be applied to node set");

 				}

 				

 				for (xpath_ast_node* n = m_right; n; n = n->m_next)

 					n->check_semantics();

 				

-				m_rettype = ast_type_node_set;

+				m_rettype = xpath_type_node_set;

 				break;

 			}

 				

 			case ast_step_root:

-				m_rettype = ast_type_node_set;

+				m_rettype = xpath_type_node_set;

 				break;

 			

 			default:

@@ -2814,7 +2805,7 @@ namespace pugi
 			}

 		}

 		

-		ast_rettype_t rettype() const

+		xpath_type_t rettype() const

 		{

 			return m_rettype;

 		}

@@ -3608,6 +3599,13 @@ namespace pugi
 		m_root->check_semantics();

 	}

 

+	xpath_type_t xpath_query::return_type() const

+	{

+		if (!m_root) return xpath_type_none;

+

+		return m_root->rettype();

+	}

+

 	bool xpath_query::evaluate_boolean(const xml_node& n) const

 	{

 		if (!m_root) return false;

@@ -3653,7 +3651,7 @@ namespace pugi
 	xpath_node_set xpath_query::evaluate_node_set(const xml_node& n) const

 	{

 		if (!m_root) return xpath_node_set();

-		if (m_root->rettype() != ast_type_node_set) throw xpath_exception("Expression does not evaluate to node set");

+		if (m_root->rettype() != xpath_type_node_set) throw xpath_exception("Expression does not evaluate to node set");

 		

 		xpath_context c;