diff --git a/CHANGELOG.md b/CHANGELOG.md new file mode 100644 --- /dev/null +++ b/CHANGELOG.md @@ -0,0 +1,12 @@ +# Changelog + +`hslua-repl` uses [PVP Versioning](https://pvp.haskell.org). + +## hslua-repl-0.1.0 + +Release pending. + +- A new package begins its way into the undiscovered land. May + it live long and prosper. + + [PVP Versioning]: https://pvp.haskell.org diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,20 @@ +Copyright © 2023 Albert Krewinkel + +Permission is hereby granted, free of charge, to any person obtaining a +copy of this software and associated documentation files (the +"Software"), to deal in the Software without restriction, including +without limitation the rights to use, copy, modify, merge, publish, +distribute, sublicense, and/or sell copies of the Software, and to +permit persons to whom the Software is furnished to do so, subject to +the following conditions: + +The above copyright notice and this permission notice shall be included +in all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. +IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY +CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, +TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE +SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. diff --git a/README.md b/README.md new file mode 100644 --- /dev/null +++ b/README.md @@ -0,0 +1,19 @@ +hslua-repl +========== + +An embeddable, isocline-based Lua REPL. + +Example +------- + +``` haskell +{-# LANGUAGE OverloadedStrings #-} +{-# LANGUAGE TypeApplications #-} +import HsLua.Core as Lua (Exception, openlibs, run) +import HsLua.REPL (defaultREPLConfig, startREPL) + +-- | Run a default Lua interpreter. +main :: IO () +main = run @Lua.Exception $ do + startREPL defaultREPLConfig +``` diff --git a/app/luarepl.hs b/app/luarepl.hs new file mode 100644 --- /dev/null +++ b/app/luarepl.hs @@ -0,0 +1,28 @@ +{-# LANGUAGE OverloadedStrings #-} +{-# LANGUAGE TypeApplications #-} +{- | +Module : Main +Copyright : © 2022-2023 Albert Krewinkel +License : MIT +Maintainer : Albert Krewinkel + +A simple Lua REPL. +-} +module Main (main) where +import Control.Monad (void) +import HsLua.Core as Lua (Exception, openlibs, run) +import HsLua.REPL (Config (..), defaultConfig, repl, setup) +import qualified Data.Text as T + +-- | Run a default Lua interpreter. +main :: IO () +main = run @Lua.Exception $ do + let config = Config + { replPrompt = "luarepl" + , replInfo = replInfo defaultConfig `T.append` + "\nREPL: © 2023 Albert Krewinkel" + , replHistory = Just ".luarepl-history" + } + openlibs + setup config + void repl diff --git a/hslua-repl.cabal b/hslua-repl.cabal new file mode 100644 --- /dev/null +++ b/hslua-repl.cabal @@ -0,0 +1,78 @@ +cabal-version: 2.2 +name: hslua-repl +version: 0.1.0 +synopsis: Isocline-based Lua REPL +description: An embeddable Lua REPL built with Isocline and HsLua. +homepage: https://hslua.org/ +bug-reports: https://github.com/hslua/hslua/issues +license: MIT +license-file: LICENSE +author: Albert Krewinkel +maintainer: Albert Krewinkel +copyright: © lbert Krewinkel +category: Foreign +build-type: Simple +extra-doc-files: README.md + CHANGELOG.md +tested-with: GHC == 8.4.4 + , GHC == 8.6.5 + , GHC == 8.8.4 + , GHC == 8.10.7 + , GHC == 9.0.2 + , GHC == 9.2.5 + , GHC == 9.4.4 + +source-repository head + type: git + location: https://github.com/hslua/hslua + subdir: hslua-repl + +Flag executable + description: Compile `luarepl` standalone executable. + default: False + +common common-options + build-depends: base >= 4.9.1 && < 5 + , hslua-core >= 2.3 && < 2.4 + , text >= 1.2 && < 2.1 + + ghc-options: -Wall + -Wcpp-undef + -Widentities + -Wincomplete-record-updates + -Wincomplete-uni-patterns + -Wmissing-export-lists + -Wmissing-signatures + -Wnoncanonical-monad-instances + -Wpartial-fields + -Wredundant-constraints + -fhide-source-paths + + if impl(ghc >= 8.10) + ghc-options: -Wunused-packages + + if impl(ghc >= 9.0) + ghc-options: -Winvalid-haddock + + + default-language: Haskell2010 + +library + import: common-options + hs-source-dirs: src + exposed-modules: HsLua.REPL + build-depends: base >= 4.11 && < 5 + , bytestring >= 0.10 && < 0.12 + , isocline >= 1.0 && < 1.1 + , lua >= 2.3 && < 2.4 + +executable luarepl + import: common-options + hs-source-dirs: app + main-is: luarepl.hs + ghc-options: -rtsopts -with-rtsopts=-A8m -threaded + if flag(executable) + buildable: True + build-depends: hslua-repl + else + buildable: False diff --git a/src/HsLua/REPL.hs b/src/HsLua/REPL.hs new file mode 100644 --- /dev/null +++ b/src/HsLua/REPL.hs @@ -0,0 +1,123 @@ +{-# LANGUAGE CPP #-} +{-# LANGUAGE LambdaCase #-} +{-# LANGUAGE OverloadedStrings #-} +{-# LANGUAGE PatternSynonyms #-} +{-# LANGUAGE ScopedTypeVariables #-} +{- | +Module : HsLua.REPL +Copyright : Copyright © 2017-2023 Albert Krewinkel +License : MIT +Maintainer : Albert Krewinkel + +Embeddable Lua interpreter interface. +-} +module HsLua.REPL + ( -- * Run scripts as program + repl + , setup + , Config (..) + , defaultConfig + ) where + +import Control.Applicative ((<|>)) +import Control.Monad (void, when) +import Data.ByteString (ByteString) +import Data.Text (Text) +import Lua (pattern LUA_COPYRIGHT) +import HsLua.Core +import System.Console.Isocline +import qualified Data.ByteString.Char8 as Char8 +import qualified Data.Text as T +import qualified Data.Text.IO as T +import qualified HsLua.Core.Utf8 as UTF8 + +-- | Lua runner command line options. +data Config = Config + { replPrompt :: Text + , replInfo :: Text + , replHistory :: Maybe FilePath + } + +defaultConfig :: Config +defaultConfig = Config + { replPrompt = "" + , replInfo = T.pack LUA_COPYRIGHT + , replHistory = Nothing + } + +-- | Setup a new repl. Prints the version and extra info before the +-- first prompt. +setup :: Config -> LuaE e () +setup config = do + liftIO $ T.putStrLn (replInfo config) + case replHistory config of + Just histfile -> liftIO $ setHistory histfile 200 + Nothing -> pure () + +-- | Checks if the error message hints at incomplete input. Removes the +-- message from the stack in that case. +incomplete :: LuaError e => LuaE e Bool +incomplete = do + let eofmark = "" + msg <- tostring' top + if eofmark `Char8.isSuffixOf` msg + then True <$ pop 2 -- error message (duplicated by tostring') + else False <$ pop 1 -- value pushed by tostring' + +-- | Load an input string, mark it as coming from @stdin@. +loadinput :: ByteString -> LuaE e Status +loadinput inp = loadbuffer inp "=stdin" + +-- | Try to load input while prepending a @return@ statement. +loadExpression :: LuaError e => ByteString -> LuaE e () +loadExpression input = loadinput ("return " <> input) >>= \case + OK -> pure () -- yep, that worked + _err -> throwErrorAsException + +-- | Load a multiline statement; prompts for more lines if the statement +-- looks incomplete. +loadStatement :: LuaError e + => [ByteString] -- ^ input lines + -> LuaE e () +loadStatement lns = do + loadinput (Char8.unlines $ reverse lns) >>= \case + OK -> pure () + ErrSyntax -> incomplete >>= \isincmplt -> + if isincmplt + then liftIO (readlineMaybe ">") >>= \case + Nothing -> failLua "Multiline input aborted" + Just input -> loadStatement (UTF8.fromString input : lns) + else throwErrorAsException + _ -> throwErrorAsException + +-- | Run a Lua repl. +repl :: LuaError e => LuaE e NumResults +repl = try repl' >>= \case + Right n -> pure n -- Ctrl-D or Ctrl-C + Left err -> do + -- something went wrong: report error, reset stack and try again + void $ getglobal "print" + pushException err + call 1 0 + settop 0 + repl + where + repl' :: LuaError e => LuaE e NumResults + repl' = liftIO (readlineMaybe "") >>= \case + Nothing -> + -- Return all values left on the stack as results + NumResults . fromStackIndex <$> gettop + Just inputStr -> do + settop 0 -- reset stack + let input = UTF8.fromString inputStr + loadExpression input <|> loadStatement [input] + -- run loaded input + callTrace 0 multret + nvalues <- gettop + -- duplicate everything and call print on the results + checkstack' (fromIntegral (fromStackIndex nvalues) + 1) "repl'" + when (nvalues > 0) $ do + void $ getglobal "print" + mapM_ pushvalue [1..nvalues] + call (fromIntegral $ fromStackIndex nvalues) 0 + repl'