Simplify dialect parse_create

Author: aharpervc

src/dialect/mssql.rs

@@ -220,21 +220,14 @@ impl MsSqlDialect {
 
     /// Parse a SQL CREATE statement
     fn parse_create(&self, parser: &mut Parser) -> Option<Result<Statement, ParserError>> {
-        let original_index = parser.index();
-
-        if !parser.parse_keyword(Keyword::CREATE) {
-            parser.set_index(original_index);
-            return None;
-        }
-
-        let or_alter = parser.parse_keywords(&[Keyword::OR, Keyword::ALTER]);
-
-        if parser.parse_keyword(Keyword::TRIGGER) {
-            return Some(self.parse_create_trigger(parser, or_alter));
-        }
-
-        parser.set_index(original_index);
-        None
+        let result = parser.maybe_parse(|p| {
+            p.expect_keyword(Keyword::CREATE)?;
+            let or_alter = p.parse_keywords(&[Keyword::OR, Keyword::ALTER]);
+            p.expect_keyword(Keyword::TRIGGER)?;
+            self.parse_create_trigger(p, or_alter)
+        });
+
+        result.ok()?.map(Ok)
     }
 
     /// Parse `CREATE TRIGGER` for [MsSql]

src/parser/mod.rs

@@ -15081,11 +15081,6 @@ impl<'a> Parser<'a> {
         self.index
     }
 
-    /// Manually change the parser index.
-    pub(crate) fn set_index(&mut self, index: usize) {
-        self.index = index;
-    }
-
     pub fn parse_named_window(&mut self) -> Result<NamedWindowDefinition, ParserError> {
         let ident = self.parse_identifier()?;
         self.expect_keyword_is(Keyword::AS)?;