Method write_child

datafusion/physical-expr/src/expressions/binary.rs:133–150

(
            f: &mut std::fmt::Formatter,
            expr: &dyn PhysicalExpr,
            precedence: u8,
        )

        // equivalent and the parentheses are not necessary.

        fn write_child(
            f: &mut std::fmt::Formatter,
            expr: &dyn PhysicalExpr,
            precedence: u8,
        ) -> std::fmt::Result {
            if let Some(child) = expr.downcast_ref::<BinaryExpr>() {
                let p = child.op.precedence();
                if p == 0 || p < precedence {
                    write!(f, "({child})")?;
                } else {
                    write!(f, "{child}")?;
                }
            } else {
                write!(f, "{expr}")?;
            }

            Ok(())
        }

        let precedence = self.op.precedence();
        write_child(f, self.left.as_ref(), precedence)?;