How can I use the hoogle command line flags when using hoogle inside ghci?
This obviously doesn't work:
ghci> :hoogle --count=5 Char -> Int
Could not read as type Int, "5 Char -> Int"
You need to change your ghci.conf in order to do this. Assuming you did the steps described on haskell.org, your ghci.conf contains a line like
:def hoogle \x -> return $ ":!hoogle \"" ++ x ++ "\""
However, that line says that :hoogle x will be translated to hoogle "x", which obviously won't work if you want to apply additional flags, such as --count=5.
You either need to remove the quotes around the argument, e.g.
:def hoogleP \x -> return $ ":!hoogle " ++ x
and use :hoogleP --count=5 "Char -> Int" or split the argument by hand into count and search query:
:def hoogleC \x -> return $ ":!hoogle --count="++(head.words $x)++" \"" ++ (unwords.tail.words $x) ++ "\""
The last version can be used as :hoogleC 5 Char -> Int.