Add Visitor Pattern , JSON_VISITOR and PRINT_JSON_VISITOR

json/visitor/json_visitor.e

@@ -0,0 +1,61 @@
+indexing
+	description:
+
+		"JSON Visitor"
+
+	pattern: "Visitor"
+	author: "Javier Velilla"
+	license:"MIT (see http://www.opensource.org/licenses/mit-license.php)"
+	date: "2008/08/24"
+	revision: "Revision 0.1"
+
+deferred class
+	JSON_VISITOR
+
+feature -- Visitor Pattern
+
+	visit_json_array (a_json_array: JSON_ARRAY) is
+			-- Visit `a_json_array'.
+		require
+			a_json_array_not_void: a_json_array /= Void
+		deferred
+		end
+
+	visit_json_boolean (a_json_boolean: JSON_BOOLEAN) is
+			-- Visit `a_json_boolean'.
+		require
+			a_json_boolean_not_void: a_json_boolean /= Void
+		deferred
+		end
+
+	visit_json_null (a_json_null: JSON_NULL) is
+			-- Visit `a_json_null'.
+		require
+			a_json_null_not_void: a_json_null /= Void
+		deferred
+		end
+
+
+	visit_json_number (a_json_number: JSON_NUMBER) is
+			-- Visit `a_json_number'.
+		require
+			a_json_number_not_void: a_json_number /= Void
+		deferred
+		end
+
+	visit_json_object (a_json_object: JSON_OBJECT) is
+			-- Visit `a_json_object'.
+		require
+			a_json_object_not_void: a_json_object /= Void
+		deferred
+		end
+
+    visit_json_string (a_json_string: JSON_STRING) is
+			-- Visit `a_json_string'.
+		require
+			a_json_string_not_void: a_json_string /= Void
+		deferred
+		end
+
+
+end

json/visitor/print_json_visitor.e

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+indexing
+	description: "PRINT_JSON_VISITOR Generates the JSON-String for a JSON_VALUE"
+	author: "jvelilla"
+	date: "2008/08/24"
+	revision: "0.1"
+
+class
+	PRINT_JSON_VISITOR
+
+inherit
+	JSON_VISITOR
+
+create make
+
+feature -- Initialization
+	make is
+			-- Create a new instance
+		do
+				create to_json.make_empty
+		end
+
+feature -- Access
+
+	to_json:STRING
+		-- JSON representation
+feature -- Visitor Pattern
+
+	visit_json_array (a_json_array: JSON_ARRAY) is
+			-- Visit `a_json_array'.
+		local
+				value:JSON_VALUE
+				l_json_array:ARRAYED_LIST[JSON_VALUE]
+		do
+				l_json_array:=a_json_array.array_representation
+				to_json.append("[")
+				from
+					l_json_array.start
+				until
+					l_json_array.off
+				loop
+					value:=l_json_array.item
+					value.accept (Current)
+					l_json_array.forth
+					if not l_json_array.after then
+						to_json.append(",")
+					end
+				end
+				to_json.append("]")
+		end
+
+	visit_json_boolean (a_json_boolean: JSON_BOOLEAN) is
+			-- Visit `a_json_boolean'.
+		do
+			to_json.append (a_json_boolean.item.out)
+		end
+
+	visit_json_null (a_json_null: JSON_NULL) is
+			-- Visit `a_json_null'.
+		do
+			to_json.append ("null")
+		end
+
+
+	visit_json_number (a_json_number: JSON_NUMBER) is
+			-- Visit `a_json_number'.
+		do
+			to_json.append (a_json_number.item)
+		end
+
+	visit_json_object (a_json_object: JSON_OBJECT) is
+			-- Visit `a_json_object'.
+		local
+			l_pairs: HASH_TABLE[JSON_VALUE,JSON_STRING]
+		do
+			l_pairs:=a_json_object.map_representation
+			to_json.append ("{")
+			from
+				l_pairs.start
+			until
+				l_pairs.off
+			loop
+				l_pairs.item_for_iteration.accept (Current)
+				to_json.append (":")
+				l_pairs.key_for_iteration.accept (Current)
+				l_pairs.forth
+				if not l_pairs.after then
+					to_json.append (",")
+				end
+			end
+			to_json.append ("}")
+		end
+
+    visit_json_string (a_json_string: JSON_STRING) is
+			-- Visit `a_json_string'.
+		do
+			to_json.append ("%"")
+			to_json.append (a_json_string.item)
+			to_json.append ("%"")
+		end
+
+end