[Ur] New wiki page: Rosetta Stone

[Robin Green]

In my efforts to better understand the Ur/Web standard library, I have
naturally tried to relate Ur/Web to a language I'm more familiar with
(Haskell). So here is a brief, incomplete and very approximate
phrasebook for translating between the two:

http://www.impredicative.com/wiki/index.php/Ur_Rosetta_Stone

for my own reference and for anyone else who's interested.

As I wrote there, it's more to give neophytes a quick leg up on
understanding what various Ur/Web functions do, than an exact
translation. Because Haskell doesn't have reified record types, I've
resorted to Haskell functions which operate on lists rather than
records, in some cases.

Feel free to add more translations, or indeed more languages, for the
benefit of newcomers coming from other languages.