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| 1 | +----------------------------------------------------------------------------- |
| 2 | +-- |
| 3 | +-- Module : Directive |
| 4 | +-- Copyright : |
| 5 | +-- License : MIT |
| 6 | +-- |
| 7 | +-- Maintainer : |
| 8 | +-- Stability : experimental |
| 9 | +-- Portability : |
| 10 | +-- |
| 11 | +-- | |
| 12 | +-- Directives for PSCI. |
| 13 | +-- |
| 14 | +----------------------------------------------------------------------------- |
| 15 | + |
| 16 | +module Directive where |
| 17 | + |
| 18 | +import Control.Applicative |
| 19 | +import Data.List (find, isPrefixOf) |
| 20 | + |
| 21 | +data Directive |
| 22 | + = Help |
| 23 | + | Quit |
| 24 | + | Reset |
| 25 | + | Import |
| 26 | + | Browse |
| 27 | + | Load |
| 28 | + | Type |
| 29 | + | Kind |
| 30 | + | Show |
| 31 | + |
| 32 | +-- | |
| 33 | +-- Maps given directive relating command strings. |
| 34 | +-- |
| 35 | +commands :: Directive -> [String] |
| 36 | +commands Help = ["?", "help"] |
| 37 | +commands Quit = ["quit"] |
| 38 | +commands Reset = ["reset"] |
| 39 | +commands Import = ["import"] |
| 40 | +commands Browse = ["browse"] |
| 41 | +commands Load = ["load", "module"] |
| 42 | +commands Type = ["type"] |
| 43 | +commands Kind = ["kind"] |
| 44 | +commands Show = ["show"] |
| 45 | + |
| 46 | +-- | |
| 47 | +-- Tries to parse given string into a directive. |
| 48 | +-- |
| 49 | +parseDirective :: String -> Maybe Directive |
| 50 | +parseDirective cmd = fst <$> find (matches . snd) mapping |
| 51 | + where |
| 52 | + mapping :: [(Directive, [String])] |
| 53 | + mapping = zip directives (map commands directives) |
| 54 | + |
| 55 | + matches :: [String] -> Bool |
| 56 | + matches = any (cmd `isPrefixOf`) |
| 57 | + |
| 58 | +-- | |
| 59 | +-- The help menu. |
| 60 | +-- |
| 61 | +help :: [(Directive, String, String)] |
| 62 | +help = |
| 63 | + [ (Help, "", "Show this help menu") |
| 64 | + , (Quit, "", "Quit PSCi") |
| 65 | + , (Reset, "", "Reset") |
| 66 | + , (Import, "<module>", "Import <module> for use in PSCI") |
| 67 | + , (Browse, "<module>", "Browse <module>") |
| 68 | + , (Load, "<file>", "Load <file> for importing") |
| 69 | + , (Type, "<expr>", "Show the type of <expr>") |
| 70 | + , (Kind, "<type>", "Show the kind of <type>") |
| 71 | + , (Show, "import", "Show imported modules") |
| 72 | + , (Show, "loaded", "Show loaded modules") |
| 73 | + ] |
| 74 | + |
| 75 | +-- | |
| 76 | +-- List of all avaliable directives. |
| 77 | +-- |
| 78 | +directives :: [Directive] |
| 79 | +directives = map (\(dir, _, _) -> dir) help |
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