filter required parameters for query execution

language/cypher/src/main/java/com/neueda/jetbrains/plugin/graphdb/language/cypher/lexer/Cypher.bnf

@@ -441,7 +441,9 @@ Variable ::= SymbolicNameString {
 }
 FunctionName ::= l_identifier
 ProcedureName ::= SymbolicNameString
-Parameter ::= NewParameter | OldParameter
+Parameter ::= NewParameter | OldParameter {
+    methods=[getParameterName]
+}
 OldParameter ::= "{" (SymbolicNameString | UnsignedDecimalInteger) "}"
 NewParameter ::= "$" (SymbolicNameString | UnsignedDecimalInteger)
 NodeLabel ::= ":" LabelName

language/cypher/src/main/java/com/neueda/jetbrains/plugin/graphdb/language/cypher/psi/CypherPsiImplUtil.java

@@ -69,6 +69,33 @@ public static String getFullName(CypherProcedureInvocation element) {
         return element.getProcedureInvocationBody().getText();
     }
 
+    public static String getParameterName(CypherParameter element) {
+        CypherNewParameter newParameter = element.getNewParameter();
+        CypherOldParameter oldParameter = element.getOldParameter();
+
+        if (newParameter != null) {
+            if (newParameter.getSymbolicNameString() != null) {
+                return newParameter.getSymbolicNameString().getUnescapedSymbolicNameString().getText();
+            }
+            if (newParameter.getUnsignedDecimalInteger() != null) {
+                return newParameter.getUnsignedDecimalInteger().getLInteger().getText();
+            }
+            throw new IllegalStateException("New parameter should have symbolic name or unsigned decimal integer value");
+        }
+
+        if (oldParameter != null) {
+            if (oldParameter.getSymbolicNameString() != null) {
+                return oldParameter.getSymbolicNameString().getUnescapedSymbolicNameString().getText();
+            }
+            if (oldParameter.getUnsignedDecimalInteger() != null) {
+                return oldParameter.getUnsignedDecimalInteger().getLInteger().getText();
+            }
+            throw new IllegalStateException("Old parameter should have symbolic name or unsigned decimal integer value");
+        }
+
+        throw new IllegalStateException("Parameter should have either new parameter or old parameter representation");
+    }
+
     /**
      * Safely replaces symbolic name node with new node.
      * It's possible that nothing happens if newElement is invalid. No error thrown in such case.