From 3612c78241311aec24650045827c5a3d98789194 Mon Sep 17 00:00:00 2001
From: Simon Binder <oss@simonbinder.eu>
Date: Tue, 27 Aug 2019 11:54:56 +0200
Subject: [PATCH] Introduce special token class for keywords

---
 sqlparser/lib/src/reader/tokenizer/scanner.dart | 2 +-
 sqlparser/lib/src/reader/tokenizer/token.dart   | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/sqlparser/lib/src/reader/tokenizer/scanner.dart b/sqlparser/lib/src/reader/tokenizer/scanner.dart
index 989d56bd..1dc48072 100644
--- a/sqlparser/lib/src/reader/tokenizer/scanner.dart
+++ b/sqlparser/lib/src/reader/tokenizer/scanner.dart
@@ -306,7 +306,7 @@ class Scanner {
       // not escaped, so it could be a keyword
       final text = _currentSpan.text.toUpperCase();
       if (keywords.containsKey(text)) {
-        _addToken(keywords[text]);
+        tokens.add(KeywordToken(keywords[text], _currentSpan));
       } else {
         tokens.add(IdentifierToken(false, _currentSpan));
       }
diff --git a/sqlparser/lib/src/reader/tokenizer/token.dart b/sqlparser/lib/src/reader/tokenizer/token.dart
index e7e9f500..368f6adb 100644
--- a/sqlparser/lib/src/reader/tokenizer/token.dart
+++ b/sqlparser/lib/src/reader/tokenizer/token.dart
@@ -266,6 +266,13 @@ class IdentifierToken extends Token {
       : super(TokenType.identifier, span);
 }
 
+/// Used for tokens that are keywords. We use this special class without any
+/// additional properties to ease syntax highlighting, as it allows us to find
+/// the keywords easily.
+class KeywordToken extends Token {
+  KeywordToken(TokenType type, FileSpan span) : super(type, span);
+}
+
 class TokenizerError {
   final String message;
   final SourceLocation location;