Parse Snowflake COLLATE after double-colon casts (#20)

Author: osipovartem

src/parser/mod.rs

@@ -4099,13 +4099,21 @@ impl<'a> Parser<'a> {
                 ),
             }
         } else if Token::DoubleColon == *tok {
-            Ok(Expr::Cast {
+            let cast = Expr::Cast {
                 kind: CastKind::DoubleColon,
                 expr: Box::new(expr),
                 data_type: self.parse_data_type()?,
                 array: false,
                 format: None,
-            })
+            };
+            if dialect_of!(self is SnowflakeDialect) && self.parse_keyword(Keyword::COLLATE) {
+                Ok(Expr::Collate {
+                    expr: Box::new(cast),
+                    collation: self.parse_object_name(false)?,
+                })
+            } else {
+                Ok(cast)
+            }
         } else if Token::ExclamationMark == *tok && self.dialect.supports_factorial_operator() {
             Ok(Expr::UnaryOp {
                 op: UnaryOperator::PGPostfixFactorial,

tests/sqlparser_snowflake.rs

@@ -5105,6 +5105,18 @@ fn test_timestamp_ntz_with_precision() {
     }
 }
 
+#[test]
+fn test_collate_after_double_colon_cast() {
+    let select = snowflake().verified_only_select("SELECT 'ñ'::VARCHAR COLLATE 'es'");
+    match expr_from_projection(only(&select.projection)) {
+        Expr::Collate { expr, collation } => {
+            assert_eq!(collation.to_string(), "'es'");
+            assert!(matches!(expr.as_ref(), Expr::Cast { .. }));
+        }
+        expr => panic!("Expected COLLATE expression, got {expr:?}"),
+    }
+}
+
 #[test]
 fn test_drop_constraints() {
     snowflake().verified_stmt("ALTER TABLE tbl DROP PRIMARY KEY");