Thank you for your reply. Some clarifications below...
It depends on what sort of computation you'll be doing upon those monetary values and on the expectations of your users. It's typical that payment processing applications sacrifice precision and instead prefer to deal in exact quantities
Is there a document which explains common use-cases for monetary values and best-practices for dealing with them? Any guidelines for which **Haskell** data-types to use for what kind of monetary calculations?
Here is what we are doing in our app:
* Powering web-based e-commerce checkout flows
* Allowing store owners to input tax rates
* Allowing end-customers to see product prices in different currencies (so, currency conversion)
* Various reports to see total sales, total receivables, and total payables (basically a **very** small subset of small-business accounting)
* Exporting data to full-fledged accounting systems, like Quickbooks and Xero.
Based on this use-case, which Haskell data-type would you suggest?