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I find it handy in Python or Common Lisp that you can list a library's contents at runtime. Does Haskell have the same thing, in particular from a GHCI prompt?
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Simply type a let followed by a newline: let ⏎. Then fac 0 = 1 ⏎. Then fac n = n * fac (n-1) ⏎ ⏎ and you're done!
Quits GHCi. You can also quit by typing control-D at the prompt. Attempts to reload the current target set (see :load ) if any of the modules in the set, or any dependent module, has changed.
GHCi is the interactive interface to GHC. From the command line, enter "ghci" (or "ghci -W") followed by an optional filename to load. Note: We recommend using "ghci -W", which tells GHC to output useful warning messages in more situations. These warnings help to avoid common programming errors.
GHCi [1] is GHC's interactive environment that includes an interactive debugger (see The GHCi Debugger). GHCi can. interactively evaluate Haskell expressions. interpret Haskell programs. load GHC-compiled modules.
GHCi has a :browse command to list the contents of modules:
Prelude> :browse Data.List (\\) :: (Eq a) => [a] -> [a] -> [a] delete :: (Eq a) => a -> [a] -> [a] deleteBy :: (a -> a -> Bool) -> a -> [a] -> [a] deleteFirstsBy :: (a -> a -> Bool) -> [a] -> [a] -> [a] elemIndex :: (Eq a) => a -> [a] -> Maybe Int ... Prelude> :help ... :browse[!] [[*]<mod>] display the names defined by module <mod> (!: more details; *: all top-level names) ... Depending on exactly what information you intend to extract... If your version of GHCi supports tab-completion, then you can use that to list all of a namespace's available functions:
Prelude> :m +Data.List Prelude Data.List> Data.List.<PRESS TAB KEY HERE> Display all 109 possibilities? (y or n) <PRESS n> Prelude Data.List> Data.List.un<PRESS TAB KEY HERE> Data.List.unfoldr Data.List.unlines Data.List.unzip3 Data.List.unzip6 Data.List.union Data.List.unwords Data.List.unzip4 Data.List.unzip7 Data.List.unionBy Data.List.unzip Data.List.unzip5 If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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