Filter required parameters for query execution (#26)

* filter required parameters for query execution
* find query parameters in PsiTree
* Extending PSI element
* get parameter name from CypherParameter attributes
* getParameterName - return hardcoded String instead of throwing exception

Author: gdalecka

language/cypher/src/main/gen/com/neueda/jetbrains/plugin/graphdb/language/cypher/CypherParser.java

@@ -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/gen/com/neueda/jetbrains/plugin/graphdb/language/cypher/psi/CypherParameter.java

@@ -69,6 +69,30 @@ public static String getFullName(CypherProcedureInvocation element) {
         return element.getProcedureInvocationBody().getText();
     }
 
+    public static String getParameterName(CypherParameter element) {
+        if (element.getNewParameter() != null) {
+            CypherNewParameter newParameter = element.getNewParameter();
+            if (newParameter.getSymbolicNameString() != null) {
+                return newParameter.getSymbolicNameString().getUnescapedSymbolicNameString().getText();
+            }
+            if (newParameter.getUnsignedDecimalInteger() != null) {
+                return newParameter.getUnsignedDecimalInteger().getLInteger().getText();
+            }
+        }
+
+        if (element.getOldParameter() != null) {
+            CypherOldParameter oldParameter = element.getOldParameter();
+            if (oldParameter.getSymbolicNameString() != null) {
+                return oldParameter.getSymbolicNameString().getUnescapedSymbolicNameString().getText();
+            }
+            if (oldParameter.getUnsignedDecimalInteger() != null) {
+                return oldParameter.getUnsignedDecimalInteger().getLInteger().getText();
+            }
+        }
+
+        return "graphbdb-plugin-invalid-parameter-name-should-never-happen";
+    }
+
     /**
      * Safely replaces symbolic name node with new node.
      * It's possible that nothing happens if newElement is invalid. No error thrown in such case.