| Line No. | Rev | Author | Line |
|---|---|---|---|
| 1 | 1 | paulosilva | |
| 2 | {-# LANGUAGE FlexibleContexts #-} | ||
| 3 | {-# OPTIONS_GHC -Wall #-} | ||
| 4 | |||
| 5 | ------------------------------------------------------------------------------- | ||
| 6 | |||
| 7 | {- | | ||
| 8 | Module : Galculator.Interpreter | ||
| 9 | Description : Command line interpreter of Galculator. | ||
| 10 | Copyright : (c) Paulo Silva | ||
| 11 | License : LGPL | ||
| 12 | |||
| 13 | Maintainer : paufil@di.uminho.pt | ||
| 14 | Stability : experimental | ||
| 15 | Portability : portable | ||
| 16 | |||
| 17 | -} | ||
| 18 | |||
| 19 | ------------------------------------------------------------------------------- | ||
| 20 | |||
| 21 | module Galculator.Interpreter ( | ||
| 22 | interactiveUI | ||
| 23 | ) where | ||
| 24 | |||
| 25 | import Control.GalcError | ||
| 26 | import Control.Monad.Error | ||
| 27 | import Control.Monad.Fresh | ||
| 28 | import Control.Monad.Trans | ||
| 29 | import Data.Char( isSpace ) | ||
| 30 | import Data.IORef | ||
| 31 | import Data.List | ||
| 32 | import Galculator.RunCommand | ||
| 33 | import Galculator.State | ||
| 34 | import Language.Command.Parser | ||
| 35 | import Language.Command.Syntax | ||
| 36 | import System.Console.Readline | ||
| 37 | |||
| 38 | |||
| 39 | ------------------------------------------------------------------------------- | ||
| 40 | |||
| 41 | -- | Sets the interactive environment: initializes the readline library, puts | ||
| 42 | -- the welcome banner and lanches the interactive loop with the initial state. | ||
| 43 | -- At exit resets the readline library. | ||
| 44 | interactiveUI :: IO () | ||
| 45 | interactiveUI = do | ||
| 46 | initialize | ||
| 47 | setAttemptedCompletionFunction $ Just completeCommand | ||
| 48 | putStrLn galculatorBanner | ||
| 49 | startGalculator interactiveLoop emptyState | ||
| 50 | putStrLn "Leaving Galculator" | ||
| 51 | resetTerminal Nothing | ||
| 52 | return () | ||
| 53 | |||
| 54 | ------------------------------------------------------------------------------- | ||
| 55 | |||
| 56 | -- | Initializes a new session with a given state. | ||
| 57 | startGalculator :: FreshT [String] GalcState a -> GalcSt -> IO a | ||
| 58 | startGalculator g state = | ||
| 59 | aux (evalFreshT g (map show ([1..]::[Integer]))) state | ||
| 60 | where aux :: GalcState a -> GalcSt -> IO a | ||
| 61 | aux g' state' = do | ||
| 62 | ref <- newIORef state' | ||
| 63 | unGalcState g' ref | ||
| 64 | |||
| 65 | ------------------------------------------------------------------------------- | ||
| 66 | |||
| 67 | prompt :: String | ||
| 68 | prompt = "Galculator> " | ||
| 69 | |||
| 70 | ------------------------------------------------------------------------------- | ||
| 71 | |||
| 72 | interactiveLoop :: FreshT [String] GalcState () | ||
| 73 | interactiveLoop = runErrorT (interactiveLoop') >> return () | ||
| 74 | |||
| 75 | ------------------------------------------------------------------------------- | ||
| 76 | |||
| 77 | interactiveLoop' :: GalcStateT () | ||
| 78 | interactiveLoop' = do | ||
| 79 | cmd <- liftIO . readline $ prompt | ||
| 80 | exit <- maybe (return False) aux cmd | ||
| 81 | if exit then return () else interactiveLoop' | ||
| 82 | where | ||
| 83 | aux c = if null . removeSpaces $ c | ||
| 84 | then return False | ||
| 85 | else (do | ||
| 86 | liftIO . addHistory $ c | ||
| 87 | runCommand =<< parser c) `catchError` showError | ||
| 88 | |||
| 89 | ------------------------------------------------------------------------------- | ||
| 90 | |||
| 91 | showError :: GalcError -> GalcStateT Bool | ||
| 92 | 7 | paulosilva | showError = keepGoing . liftIO . putStrLn . (++) "***Galculator error:\n" . show |
| 93 | 1 | paulosilva | |
| 94 | ------------------------------------------------------------------------------- | ||
| 95 | |||
| 96 | completeCommand :: String -> Int -> Int -> IO (Maybe (String, [String])) | ||
| 97 | completeCommand str _ _ = do | ||
| 98 | let lst = foldr (\c r -> if str `isPrefixOf` c then c:r else r) [] commands | ||
| 99 | case lst of | ||
| 100 | [] -> return Nothing | ||
| 101 | [x] -> return $ Just (x,[]) | ||
| 102 | xs -> return $ Just (getCommonPrefix xs, xs) | ||
| 103 | |||
| 104 | ------------------------------------------------------------------------------- | ||
| 105 | -- Stollen from GHCi | ||
| 106 | getCommonPrefix :: [String] -> String | ||
| 107 | getCommonPrefix [] = "" | ||
| 108 | getCommonPrefix (str:ss) = foldl common str ss | ||
| 109 | where common _ "" = "" | ||
| 110 | common "" _ = "" | ||
| 111 | common (c:cs) (d:ds) | ||
| 112 | | c == d = c : common cs ds | ||
| 113 | | otherwise = "" | ||
| 114 | |||
| 115 | ------------------------------------------------------------------------------- | ||
| 116 | -- Stollen from GHC Utils | ||
| 117 | removeSpaces :: String -> String | ||
| 118 | removeSpaces = reverse . dropWhile isSpace . reverse . dropWhile isSpace | ||
| 119 | |||
| 120 | ------------------------------------------------------------------------------- | ||
| 121 | |||
| 122 | galculatorBanner :: String | ||
| 123 | galculatorBanner = | ||
| 124 | " ___ __ _ ___ _ _ _ __ _____ __ ___ \n" ++ | ||
| 125 | " / _ \\ / \\ | | / __|| | | || | / \\ |_ _|/ \\| \\\n" ++ | ||
| 126 | " / /_\\/ / /\\ \\ | | | | | | | || | / /\\ \\ | | | | || /\n" ++ | ||
| 127 | "/ /_\\\\ / ___ \\| |___| |__ | |_| || |___ / ___ \\ | | | | || |\\ \\\n" ++ | ||
| 128 | "\\____//_/ \\_/ \\____|\\___|\\____/ \\____|/_/ \\_/ |_| \\___/|_| \\_\\\n\n" ++ | ||
| 129 | " Paulo Silva (paufil@di.uminho.pt)\n" ++ | ||
| 130 | " Universidade do Minho, Braga, Portugal\n" | ||
| 131 | |||
| 132 | ------------------------------------------------------------------------------- |