Method metadata

datafusion/expr/src/expr_schema.rs:400–403

(&self, schema: &dyn ExprSchema)

    }

    fn metadata(&self, schema: &dyn ExprSchema) -> Result<FieldMetadata> {
        self.to_field(schema)
            .map(|(_, field)| FieldMetadata::from(field.metadata()))
    }

    /// Returns the datatype and nullability of the expression based on [ExprSchema].
    ///