Some more-tested parts from my GHCi config

.ghci

-- Use a green "λ>" as prompt. (Continued lines begin with " |".)
:set prompt  "\SOH\ESC[32;1m\STXλ>\SOH\ESC[0m\STX "
:set prompt2 "\SOH\ESC[32;1m\STX |\SOH\ESC[0m\STX "

-- Hoogle (cabal install hoogle && hoogle data)
:def hoogle     \str -> return $ ":! hoogle search --color --count=10 " ++ show str
:def hoogle-all \str -> return $ ":! hoogle search --color "            ++ show str
:def doc        \str -> return $ ":! hoogle search --color --info "     ++ show str

-- Pointfree (cabal install pointfree)
:def pointfree \str -> return $ ":! pointfree " ++ show str
:def pf        \str -> return $ ":! pointfree " ++ show str