[Haskell-cafe] Finally tagless and abstract relational Algebra

[Günther Schmidt]

Hi,

I'm still trying to build an *abstract* Relation Algebra using the 
finally tagless style.

My guess is that finally tagless style allows one to create a syntax 
without any initial dependency to an implementation. Ie. once one has 
created the syntax in this style one can then proceed to construct terms.

So this is my goal, create a syntax for relational algebra, express an 
abstract relational algorithm in this syntax and worry about 
implementation / compilation / evaluation *later*. But at least being 
able to express a correctly typed term.

I presume I will need to employ HList at some point, but I'm not 
entirely certain where. Will I need it at the very beginning, as 
constrains in the syntax so that only correct abstract terms can be 
built, or will I need it in on of the interpreters / compilers later?

Günther