Try to inline the function based on code review feedback

Author: yoavcloud

src/dialect/mod.rs

@@ -561,6 +561,11 @@ pub trait Dialect: Debug + Any {
     fn supports_asc_desc_in_column_definition(&self) -> bool {
         false
     }
+
+    /// For example: SELECT col_alias = col FROM tbl
+    fn supports_eq_alias_assigment(&self) -> bool {
+        false
+    }
 }
 
 /// This represents the operators for which precedence must be defined

src/dialect/mssql.rs

@@ -49,4 +49,8 @@ impl Dialect for MsSqlDialect {
     fn supports_connect_by(&self) -> bool {
         true
     }
+
+    fn supports_eq_alias_assigment(&self) -> bool {
+        true
+    }
 }

src/parser/mod.rs

@@ -11174,11 +11174,29 @@ impl<'a> Parser<'a> {
                 )
             }
             expr => {
-                if dialect_of!(self is MsSqlDialect) {
-                    if let Some(select_item) = self.parse_mssql_alias_with_equal(&expr) {
-                        return Ok(select_item);
+                // Parse a [`SelectItem`] based on an [MsSql] syntax that uses the equal sign
+                // to denote an alias, for example: SELECT col_alias = col FROM tbl
+                // [MsSql]: https://learn.microsoft.com/en-us/sql/t-sql/queries/select-examples-transact-sql?view=sql-server-ver16#b-use-select-with-column-headings-and-calculations
+                let expr = if self.dialect.supports_eq_alias_assigment() {
+                    if let Expr::BinaryOp {
+                        ref left,
+                        op: BinaryOperator::Eq,
+                        ref right,
+                    } = expr
+                    {
+                        if let Expr::Identifier(alias) = left.as_ref() {
+                            return Ok(SelectItem::ExprWithAlias {
+                                expr: *right.clone(),
+                                alias: alias.clone(),
+                            });
+                        }
                     }
-                }
+                    expr
+                } else {
+                    expr
+                };
+
+                // Parse the common AS keyword for aliasing a column
                 self.parse_optional_alias(keywords::RESERVED_FOR_COLUMN_ALIAS)
                     .map(|alias| match alias {
                         Some(alias) => SelectItem::ExprWithAlias { expr, alias },
@@ -11188,27 +11206,6 @@ impl<'a> Parser<'a> {
         }
     }
 
-    /// Parse a [`SelectItem`] based on an MsSql syntax that uses the equal sign
-    /// to denote an alias, for example: SELECT col_alias = col FROM tbl
-    /// <https://learn.microsoft.com/en-us/sql/t-sql/queries/select-examples-transact-sql?view=sql-server-ver16#b-use-select-with-column-headings-and-calculations>    
-    fn parse_mssql_alias_with_equal(&mut self, expr: &Expr) -> Option<SelectItem> {
-        if let Expr::BinaryOp {
-            left, op, right, ..
-        } = expr
-        {
-            if op == &BinaryOperator::Eq {
-                if let Expr::Identifier(ref alias) = **left {
-                    return Some(SelectItem::ExprWithAlias {
-                        expr: *right.clone(),
-                        alias: alias.clone(),
-                    });
-                }
-            }
-        }
-
-        None
-    }
-
     /// Parse an [`WildcardAdditionalOptions`] information for wildcard select items.
     ///
     /// If it is not possible to parse it, will return an option.