I started out using the Haskell “Rational” type [1] (which is exactly what you mention) for https://cryptomarketdepth.com/ https://cryptomarketdepth.com/ but I

I started out using the Haskell “Rational” type [1] (which is exactly what you mention) for https://cryptomarketdepth.com/ https://cryptomarketdepth.com/ but I had to abandon it because it was horribly slow. I was multiplying numbers with roughly 8 decimal places, and once I had done this like 100 times my program spent almost all its time trying to simplify fractions with a 1000 digit numerator and denominator. [1] https://www.stackage.org/haddock/lts-20.10/base-4.16.4.0/Prelude.html#t:Rational https://www.stackage.org/haddock/lts-20.10/base-4.16.4.0/Pre...