[Template-haskell] reifyDecl: syntax and semantics

[François-Régis Sinot]

> Reification is difficult for lots of reasons. But here is a trick that
> you might be able to use.
> 
> Break your program into pieces, where you split the use of decls
> you want to reify into two parts.
> 
> --------------------
> d1 = [d| data T = ... |]
> 
> splice d1
> 
> ---------------------
> 
> Then you have a meta-variable "d1" with the reified form, and the
> real data declaration because of the splice.
> 
> Tim Sheard


I definitely prefer your solution which just avoids reification, for
one simple reason: it works !
Question is: is there any case where reification is indispensable or is
this trick general ? (and then why bother with reification ?)

However, I'm still not very happy with this solution, because (again)
thinking of a library working on the reified declarations, then the
part above has to be written by the "user".

Thanks.

-fr-