But there's already multiple existing configuration languages that's far more legible and robust than custom languages implemented on top of XML. Take Nickel.
This:
let
totalOwed = totalTax - totalPayments,
totalTax = tentativeTaxNetNonRefundableCredits + totalOtherTaxes,
totalPayments = totalEstimatedTaxesPaid +
totalTaxesPaidOnSocialSecurityIncome +
totalRefundableCredits,
in
totalPayments
is easy to read, unlike XML. It's written in a small configuration language that's easy to learn. It's pure and declarative. It handles complex configurations well. It provides tools to quickly pinpoint configuration errors. It can be integrated into existing software and workflows. Compared to bespoke languages built on top of XML, it's an improvement in every way conceivable.There are also varieties of other languages to choose from. Using a bespoke XML-based language will inflict needless suffering upon people.
> This Constitution, and the Laws of the United States which shall be made in Pursuance thereof; and all Treaties made, or which shall be made, under the Authority of the United States, shall be the supreme Law of the Land; and the Judges in every State shall be bound thereby, any Thing in the Constitution or Laws of any State to the Contrary notwithstanding.