Move HqlToken.PossibleId to HqlParser.IsPossibleId method and remove castings (#3377)

src/NHibernate/Hql/Ast/ANTLR/HqlParser.cs

@@ -147,8 +147,8 @@ public void WeakKeywords()
 					// Case 2: The current token is after FROM and before '.'.
                     if (t != IDENT && input.LA(-1) == FROM && ((input.LA(2) == DOT) || (input.LA(2) == IDENT) || (input.LA(2) == -1)))
 					{
-						HqlToken hqlToken = input.LT(1) as HqlToken;
-						if (hqlToken != null && hqlToken.PossibleId)
+						var hqlToken = input.LT(1);
+						if (IsPossibleId(hqlToken))
 						{
 							hqlToken.Type = IDENT;
 							if (log.IsDebugEnabled())
@@ -192,8 +192,8 @@ public void WeakKeywords2()
                     // Case 2: The current token is after FROM and before '.'.
                     if (t != IDENT && input.LA(-1) == FROM && input.LA(2) == DOT)
                     {
-                        HqlToken hqlToken = (HqlToken)input.LT(1);
-                        if (hqlToken.PossibleId)
+                        var hqlToken = input.LT(1);
+                        if (IsPossibleId(hqlToken))
                         {
                             hqlToken.Type = IDENT;
                             if (log.IsDebugEnabled())
@@ -290,16 +290,8 @@ public IASTNode NegateNode(IASTNode node)
 			}
 		}
 
-		public IASTNode ProcessEqualityExpression(object o)
+		public IASTNode ProcessEqualityExpression(IASTNode x)
 		{
-			IASTNode x = o as IASTNode;
-
-			if (x == null)
-			{
-				log.Warn("processEqualityExpression() : No expression to process!");
-				return null;
-			}
-
 			int type = x.Type;
 			if (type == EQ || type == NE)
 			{
@@ -336,11 +328,11 @@ public void HandleDotIdent()
 			if (input.LA(1) == DOT && input.LA(2) != IDENT)
 			{
 				// See if the second lookahed token can be an identifier.
-				HqlToken t = input.LT(2) as HqlToken;
-				if (t != null && t.PossibleId)
+				var t = input.LT(2);
+				if (IsPossibleId(t))
 				{
 					// Set it!
-					input.LT(2).Type = IDENT;
+					t.Type = IDENT;
 					if (log.IsDebugEnabled())
 					{
 						log.Debug("handleDotIdent() : new LT(2) token - {0}", input.LT(1));
@@ -401,37 +393,38 @@ public IASTNode ProcessMemberOf(IToken n, IASTNode p, IASTNode root)
 
 		public IASTNode HandleIdentifierError(IToken token, RecognitionException ex)
 		{
-			if (token is HqlToken)
+			// ... and the token could be an identifier and the error is
+			// a mismatched token error ...
+			if (IsPossibleId(token) && (ex is MismatchedTokenException mte)
+			    // ... and the expected token type was an identifier, then:
+			    && mte.Expecting == IDENT)
 			{
-				HqlToken hqlToken = (HqlToken)token;
+				// Use the token as an identifier.
+				_parseErrorHandler.ReportWarning("Keyword  '"
+				     + token.Text
+				     + "' is being interpreted as an identifier due to: " + mte.Message);
 
-				// ... and the token could be an identifer and the error is
-				// a mismatched token error ...
-				if (hqlToken.PossibleId && (ex is MismatchedTokenException))
-				{
-					MismatchedTokenException mte = (MismatchedTokenException)ex;
-
-					// ... and the expected token type was an identifier, then:
-					if (mte.Expecting == IDENT)
-					{
-						// Use the token as an identifier.
-						_parseErrorHandler.ReportWarning("Keyword  '"
-								+ token.Text
-								+ "' is being interpreted as an identifier due to: " + mte.Message);
+				// Add the token to the AST.
 
-						// Add the token to the AST.
+				token.Type = WEIRD_IDENT;
 
-						token.Type = WEIRD_IDENT;
-
-						input.Consume();
-						return (IASTNode) adaptor.Create(token);
-					}
-				} 
+				input.Consume();
+				return (IASTNode) adaptor.Create(token);
 			}
-			
+
 			// Otherwise, handle the error normally.
 			ReflectHelper.PreserveStackTrace(ex);
 			throw ex;
 		}
+
+		/// <summary>
+		/// Indicates if the token could be an identifier.
+		/// </summary>
+		/// <param name="token"></param>
+		public static bool IsPossibleId(IToken token)
+		{
+			var type = token.Type;
+			return type >= 0 && type < possibleIds.Length && possibleIds[type];
+		}
 	}
 }

src/NHibernate/Hql/Ast/ANTLR/HqlToken.cs

@@ -39,10 +39,9 @@ public HqlToken(IToken other)
         /// <summary>
         /// Indicates if the token could be an identifier.
         /// </summary>
-        public bool PossibleId
-        {
-            get { return HqlParser.possibleIds[Type]; }
-        }
+        // Since 5.5
+        [Obsolete("Use HqlParser.IsPossibleId method instead.")]
+        public bool PossibleId => HqlParser.IsPossibleId(this);
 
         /// <summary>
         /// Returns the previous token type.
@@ -62,7 +61,7 @@ public override string ToString()
                     + Text
                     + "\",<" + Type + "> previously: <" + PreviousType + ">,line="
                     + Line + ",col="
-                    + CharPositionInLine + ",possibleID=" + PossibleId + "]";
+                    + CharPositionInLine + ",possibleID=" + HqlParser.IsPossibleId(this) + "]";
         }
     }
 }