Having mostly been converted from hugs to ghci (due to working with too large programs or libraries more readily supported there), I've come to find it quite indispensible for Haskell development. However, there are a few corners where I still miss Hugs functionality that doesn't seem to be available in ghci, and I wonder whether there are any plans to remedy this (or whether there are any fundamental obstacles): - especially when working with gui libs, I often find myself wanting to know which instances some type belongs to (as that determines the attributes/properties/etc one may use with that type). in hugs, a simple ":info <type>" gives me the answer: Prelude> :info Bool -- type constructor data Bool -- constructors: False :: Bool True :: Bool -- instances: instance Eq Bool instance Ord Bool instance Ix Bool instance Enum Bool instance Read Bool instance Show Bool instance Bounded Bool in fact, I can even ask by class, using ":info <class>": Prelude> :i Enum -- type class class Enum a where succ :: a -> a pred :: a -> a toEnum :: Int -> a fromEnum :: a -> Int enumFrom :: a -> [a] enumFromThen :: a -> a -> [a] enumFromTo :: a -> a -> [a] enumFromThenTo :: a -> a -> a -> [a] -- instances: instance Enum () instance Enum Char instance Enum Int instance Enum Integer instance Enum Float instance Enum Double instance Integral a => Enum (Ratio a) instance Enum Bool instance Enum Ordering in ghci, such useful info seems absent, and I find myself hunting the haddocs. shouldn't ghci be able to provide this info as well? - since ghc now keeps better source location info, how about ":find <name>"? in hugs, that calls a configurable external command (usually an editor) with the filename and linenumber of <name>'s definition. this is very useful, even more so for Haskell IDEs that communicate with hugs to implement "jump to definition" instead of relying on outdated or non- existent tag files. in ghci, that could simply pass filename and linenumber to a configurable Haskell function (:: String -> Int -> IO ()) - well, if we have the source code.. so we need an indication of whether ghci knows where to find the source, and if not, we need the package and full hierarchical module and item name, so that the user-supplied "find" function could eg. try to open the corresponding haddoc entry if the source is not available, before giving up. simplified example: myfind :: Maybe (FilePath,Int) -> (String,String) -> IO ExitCode myfind (Just (filepath,line)) _ = system $ editor++" +"++show line++" "++filepath myfind Nothing (package,mp) = system $ browser++" "++haddocBase++sep++package++sep++mp++".html" :set find myfind :find MVar -- goes off to open "<somewhere>\base\Control.Concurrent.MVar.html" [ghci already offers source location information as part of ":info", *if* it has seen the source code; I'm just asking for a more convenient interface, as well as infomation in the common case of no source code] - the ":set <something>" command in ghci "feeds" the ghc command line, but how can I figure out the current settings (especially paths and packages)? in hugs ":set" would list all settings; in ghci that doesn't seem to happen. Especially the first two (instance info and configurable source/doc link would help me with frequently recurring work patterns during Haskell code development. Cheers, Claus