implemented LENGTH in C++

arangod/Aql/Executor.cpp

@@ -137,7 +137,7 @@ std::unordered_map<std::string, Function const> const Executor::FunctionNames{
   { "MINUS",                       Function("MINUS",                       "AQL_MINUS", "l,l|+", true, false, true) },
   { "INTERSECTION",                Function("INTERSECTION",                "AQL_INTERSECTION", "l,l|+", true, false, true) },
   { "FLATTEN",                     Function("FLATTEN",                     "AQL_FLATTEN", "l|n", true, false, true) },
-  { "LENGTH",                      Function("LENGTH",                      "AQL_LENGTH", "las", true, false, true) },
+  { "LENGTH",                      Function("LENGTH",                      "AQL_LENGTH", "las", true, false, true, &Functions::Length) },
   { "MIN",                         Function("MIN",                         "AQL_MIN", "l", true, false, true) },
   { "MAX",                         Function("MAX",                         "AQL_MAX", "l", true, false, true) },
   { "SUM",                         Function("SUM",                         "AQL_SUM", "l", true, false, true) },

arangod/Aql/Functions.cpp

@@ -100,6 +100,51 @@ AqlValue Functions::IsDocument (triagens::arango::AqlTransaction* trx,
   return AqlValue(new Json(j.isArray()));
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief function LENGTH
+////////////////////////////////////////////////////////////////////////////////
+
+AqlValue Functions::Length (triagens::arango::AqlTransaction* trx,
+                                TRI_document_collection_t const* collection,
+                                AqlValue const parameters) {
+  Json j(parameters.extractListMember(trx, collection, 0, false));
+
+  TRI_json_t const* json = j.json();
+  size_t length = 0;
+
+  if (json != nullptr) {
+    switch (json->_type) {
+      case TRI_JSON_UNUSED:
+      case TRI_JSON_NULL:
+        length = strlen("null"); 
+        break;
+
+      case TRI_JSON_BOOLEAN:
+        length = (json->_value._boolean ? strlen("true") : strlen("false"));
+        break;
+
+      case TRI_JSON_NUMBER:
+      case TRI_JSON_STRING:
+      case TRI_JSON_STRING_REFERENCE:
+        // return number of characters (not byteS) in string
+        length = TRI_CharLengthUtf8String(json->_value._string.data);
+        break;
+
+      case TRI_JSON_ARRAY:
+        // return number of attributes
+        length = json->_value._objects._length / 2;
+        break;
+
+      case TRI_JSON_LIST:
+        // return list length
+        length = TRI_LengthListJson(json);
+        break;
+    }
+  }
+
+  return AqlValue(new Json(static_cast<double>(length)));
+}
+
 // -----------------------------------------------------------------------------
 // --SECTION--                                                       END-OF-FILE
 // -----------------------------------------------------------------------------

arangod/Aql/Functions.h

@@ -32,6 +32,7 @@
 
 #include "Basics/Common.h"
 #include "Aql/AqlValue.h"
+#include "Basics/tri-strings.h"
 #include "Utils/AqlTransaction.h"
 
 #include <functional>
@@ -55,6 +56,7 @@ namespace triagens {
       static AqlValue IsString (triagens::arango::AqlTransaction*, TRI_document_collection_t const*, AqlValue const);
       static AqlValue IsList (triagens::arango::AqlTransaction*, TRI_document_collection_t const*, AqlValue const);
       static AqlValue IsDocument (triagens::arango::AqlTransaction*, TRI_document_collection_t const*, AqlValue const);
+      static AqlValue Length (triagens::arango::AqlTransaction*, TRI_document_collection_t const*, AqlValue const);
     };
 
   }

lib/Basics/tri-strings.h

@@ -342,9 +342,6 @@ size_t TRI_CharLengthUtf8String (const char*);
 
 char* TRI_PrefixUtf8String (const char*, const uint32_t);
 
-
-
-
 #endif
 
 // -----------------------------------------------------------------------------