Further simplification of is_null

Author: pepijnve

datafusion/expr/src/expr_schema.rs

@@ -305,8 +305,10 @@ impl ExprSchemable for Expr {
                         // For branches with a nullable 'then' expression, try to determine
                         // if the 'then' expression is ever reachable in the situation where
                         // it would evaluate to null.
-                        let bounds =
-                            predicate_bounds::evaluate_bounds(w, Some(t), input_schema);
+                        let bounds = match predicate_bounds::evaluate_bounds(w, Some(t), input_schema) {
+                            Err(e) => return Some(Err(e)),
+                            Ok(b) => b,
+                        };
 
                         if bounds.is_certainly_not_true() {
                             // The predicate will never evaluate to true, so the 'then' expression
@@ -320,7 +322,7 @@ impl ExprSchemable for Expr {
                     })
                     .next();
 
-                let result = if let Some(nullable_then) = nullable_then {
+                if let Some(nullable_then) = nullable_then {
                     // There is at least one reachable nullable then
                     nullable_then.map(|_| true)
                 } else if let Some(e) = &case.else_expr {
@@ -329,11 +331,7 @@ impl ExprSchemable for Expr {
                     // CASE produces NULL if there is no `else` expr
                     // (aka when none of the `when_then_exprs` match)
                     Ok(true)
-                };
-
-                println!("{} nullable? {result:?}", self);
-
-                result
+                }
             }
             Expr::Cast(Cast { expr, .. }) => expr.nullable(input_schema),
             Expr::ScalarFunction(_func) => {