John Cavnar-Johnson, "The 'a List"

“One more thing, we need the new system to produce our invoices/estimates/contracts/whatever as PDFs.”
Producing Portable Document Format files is one of the gnarliest problems I have to deal with on a regular basis. Tonight I’m introducing a new OSS project to make it a little simpler for F# developers to render PDFs from line of business application. Inspired by FsExcel (which in turn was inspired by Elm’s way of handling HTML markup), I’m using the humble F# list type as a developer interface to PDF generation. Even if you don’t use F# or need to render PDFs, the tools and techniques used (lists, tagged unions, records, and pattern matching) are widely available in functional languages and broadly applicable to DSL style solutions.