I need to pick among the usual list of suspects for a commercial product that I'm writing. The suspects are OCaml, Haskell and Lisp and the product is a trading studio. My idea is to write something like TradeStation [1] or NinjaTrader, only for the Mac. It would be quite nifty to use SPJ's financial combinator approach and, for example, embed Yi (Haskell editor). One of the key features of the product would be the ability to model your trading logic using a trading DSL. I'm thinking that this DSL could well be Haskell but I'm concerned about stepping into a minefield. I will need to embed GHC into the app, for example, and I understand that the GHC API does not offer unloading of code at the moment. I would prefer not to bundle GHC separately so I don't think the hs- plugins approach would work for me. Maybe I'm mistaken. Most of all, I'm concerned that my users will need to face the error reports from GHC and could get tripped by laziness, i.e. write something that would make the app run out of memory. Off the top of my head I can't figure out a way to limit what my users can do without analyzing the Haskell AST within the GHC API and complaining if necessary. Can someone with experience in offering a Haskell DSL to their users please comment? Notice that I'm not even mentioning being concerned with the unpredictable effects of laziness. There's probably a reason why Jane St Capital is using OCaml instead of Haskell. I'm not going to play in that league but my knee-jerk reaction is to use OCaml or Lisp and avoid laziness altogether. I just can't see how laziness can help in processing real-time price data. Thanks, Joel [1] http://www.tradestation.com/default_2.shtm [2] http://www.ninjatrader.com/webnew/index.htm -- http://wagerlabs.com