* Heinrich Apfelmus
Duncan Coutts wrote:
Hi folks,
I want to give you advance notice that I would like to make Cabal depend on parsec. The implication is that GHC would therefore depend on parsec and thus it would become a core package, rather than just a HP package. So this would affect both GHC and the HP, though I hope not too much.
[..]
Why did I choose parsec? Practicality dictates that I can only use things in the core libraries, and the nearest thing we have to that is the parser lib that is in the HP. I tried to use happy but I could not construct a grammar/lexer combo to handle the layout (also, happy is not exactly known for its great error messages).
Reuse is good, but the implication I'm worried about is this: Can I upgrade the parsec package installed on my system by doing a user install from hackage ? Without an implementation of more flexible package installations (multiple versions installed simultaneously), any dependency of GHC has its version number essentially set into stone.
We've had that working for a long time. Right now I even have multiple installed versions of Cabal-the-library itself. It's not that Parsec would be automatically linked into each executable. It's just that ghc-the-program would have Parsec linked into it. Roman