Hacker News Reader

Comment by LukeHoersten | Hacker News Reader

SPJ, co-author of GHC, added this awesome comment:

""Look at the implementation of other functions in GHC.Prim;they're all defined as let x = x in x."

This begs the question of why this strange code exists at all. Answer: the sole reason is to give Haddock documentation for the primops a place to live. GHC.Prim is processed by Haddock more or less like any other module; but is effectively ignored by GHC itself.

Worth saying this.

Simon"

View on HN

I never understood why these weren't

    primop = let x = x in x
    (+#) = primop

or something else at least somewhat meaningful.

I don't know the answer to that, but I suspect it might be because there is some reason for the code in GHC.Prim to be monomorphic.

There is a Stack Overflow discussion about this that gives a bit more background, by the way. (The answer needlessly digressing into the lambda calculus is mine.)

0. http://stackoverflow.com/questions/15893524/what-is-the-mean...

Reply on news.ycombinator.com