Re: [Haskell-cafe] problem implementing an EDSL in Haskell

Hi Daniil, oops -- i just noticed this response from you from weeks ago. i'm guessing your question is all resolved for you by now. if not, please say so. cheers, - Conal On 6/25/07, Daniil Elovkov wrote:

Hi Conal

...

By "embedded" DSL, we usually mean identifying meta-language (Haskell) expressions with object language (DSL) expressions, rather than having an "Exp" data type. Then you just use meta-language variables as object-language variables. The new data types you introduce are then domain-oriented rather than language-oriented. Is there a reason that

2007/6/24, Conal Elliott : this

...

kind of "embedded" approach doesn't work for you?

Hmm, sorry, I must admit I didn't quite get it.

However, in the situation I described, I don't just have an "Exp" data type, rather have it (and probably some other data types) typeful. Which lets me leverage the meta-language's (Haskell's) typing rules to enforce correctness of my DS language's expression correctness.

I absolutely didn't want to make an accent on "embedded". Sorry, if that introduced some confusion. And that's not important or principal to me, it's just how I called it.