Linguistics
2,500 years ago, one grammarian wrote language rules that read like computer code
Around the 6th century BC, the Indian scholar Panini compressed the entire grammar of Sanskrit into roughly 4,000 terse rules, using abbreviations, variables and recursive definitions so systematic that modern linguists compare its structure to a programming language. It's considered the most complete formal grammar of any language written before the 20th century, and still shapes how linguists formally describe grammar today.