Compiling in GHC

Question

I'm learning Haskell and a simple doubt struck me, what is the difference between these two commands to compile using GHC (fac is a program to calculate factorial) :

ghc -o fac fac.hs

and

ghc fac.hs

Now to run the program I just do fac.exe (I'm using Windows).

Given that both works which one is right? both? And which one is the most advisable to use?

Answer 1

Both are OK. The only thing the -o command does is determine the name of the executable file that is generated. As far as the Haskell goes it doesn't make any difference.

Personally, I like always using "-o" to make things explicit (since I like avoiding implicit defaults in general) and to make it look more similar to other compilers (for example, the gcc C compiler kind of forces you to use its "-o" option, since the default name it uses otherwise is very ugly)