return 6
	}
	return 4
}

func diffPrec(expr ast.Expr, prec int) int {
	x, ok := expr.(*ast.BinaryExpr)
	if !ok || prec != x.Op.Precedence() {
		return 1
	}
	return 0
}

func reduceDepth(depth int) int {
	depth--
	if depth < 1 {
		depth = 1
	}
	return depth
}

// Format the binary expression: decide the cutoff and then format.