improve comment

cloud-fan · cloud-fan · commit 16063a3c5a32 · 2022-06-07T21:59:46.000+08:00
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/parser/AstBuilder.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/parser/AstBuilder.scala
@@ -1795,7 +1795,8 @@ class AstBuilder extends SqlBaseParserBaseVisitor[AnyRef] with SQLConfHelper wit
         cast
 
       case SqlBaseParser.TRY_CAST =>
-        // TRY_CAST can only be user-specified and we don't need to set the Tag.
+        // `TryCast` can only be user-specified and we don't need to set the USER_SPECIFIED_CAST
+        // tag, which is only used by `Cast`
         TryCast(expression(ctx.expression), dataType)
     }
   }

Original file line number	Diff line number	Diff line change
`@@ -1795,7 +1795,8 @@ class AstBuilder extends SqlBaseParserBaseVisitor[AnyRef] with SQLConfHelper wit`
`1795`	`1795`	`cast`
`1796`	`1796`
`1797`	`1797`	`case SqlBaseParser.TRY_CAST =>`
`1798`		`- // TRY_CAST can only be user-specified and we don't need to set the Tag.`
	`1798`	+ // `TryCast` can only be user-specified and we don't need to set the USER_SPECIFIED_CAST
	`1799`	+ // tag, which is only used by `Cast`
`1799`	`1800`	`TryCast(expression(ctx.expression), dataType)`
`1800`	`1801`	`}`
`1801`	`1802`	`}`