diff --git a/BSParse.hs b/BSParse.hs new file mode 100644 --- /dev/null +++ b/BSParse.hs @@ -0,0 +1,132 @@ +{-# OPTIONS_GHC -fbang-patterns #-} +module BSParse (parseArgs,runParse,getInterp,TclWord(..),dropWhite) where +import qualified Data.ByteString.Char8 as B +import Control.Monad +import Data.Char +import Test.HUnit -- IGNORE + +data TclWord = Word B.ByteString | Subcommand [TclWord] | NoSub B.ByteString deriving (Show,Eq) + +dispatch str = do h <- safeHead str + case h of + '{' -> nested str + '[' -> parseSub str + '"' -> parseStr str + _ -> getword str + +parseArgs = multi (dispatch . dropWhite) +runParse = multi (mainparse . dropWhite) + +safeHead s = guard (not (B.null s)) >> return (B.head s) + + +getInterp str = do + loc <- B.findIndex (\x -> x == '$' || x == '[') str + let locval = B.index str loc + if escaped loc str + then do (p,v,r) <- getInterp (B.drop (loc+1) str) + return (B.append (B.take (loc-1) str) (B.cons locval p), v, r) + else let (pre,aft) = B.splitAt loc str in + case B.index str loc of + '$' -> do (s, rest) <- getword aft + return (pre, s,rest) + '[' -> do (s, rest) <- parseSub aft + return (pre, s, rest) + +mainparse str = do h <- safeHead str + case h of + ';' -> return ([], B.tail str) + '\n' -> return ([], B.tail str) + '#' -> eatcomment str + _ -> parseArgs str + +multi p s = do (w,r) <- p s + case multi p r of + Nothing -> return ([w],r) + Just (wx,r2) -> return $! (w:wx,r2) + +parseSub s = do guard (B.head s == '[') + (p,r) <- parseArgs (B.tail s) + loc <- B.elemIndex ']' r + let (pre,aft) = B.splitAt loc r + return (Subcommand p, B.tail aft) + +eatcomment = return . (,) [] . B.tail . B.dropWhile (/= '\n') + +dropWhite = B.dropWhile (\x -> x == ' ' || x == '\t') + +wordChar ' ' = False +wordChar c = let ci = ord c in + (ord 'a' <= ci && ci <= ord 'z') || (ord 'A' <= ci && ci <= ord 'Z') || + (ord '0' <= ci && ci <= ord '9') || (c `B.elem` (B.pack "+-*=/:^$%!^&<>")) + +getword s = if B.null w then fail "can't parse word" else return (Word w,n) + where (w,n) = B.span wordChar s + +parseStr s = do loc <- B.elemIndex '"' str + let (w,r) = B.splitAt loc str + if escaped loc str then do (Word w1, v) <- parseStr r + let nw = B.snoc (B.take (B.length w - 1) w) '"' + return (ueword (B.append nw w1), v) + else return (ueword w, B.tail r) + where str = B.tail s + ueword = Word . strSub (B.pack "\\t", B.singleton '\t') . strSub (B.pack "\\n",B.singleton '\n') + +strSub (from,to) s = B.concat $ reverse $ breakUp s nls + where nls = reverse $ B.findSubstrings from s + breakUp x [] = [x] + breakUp x (i:xs) = let (a,b) = B.splitAt i x in (B.drop (B.length from) b):to:breakUp a xs + +escaped v s = escaped' v + where escaped' !i = if (i <= 0) then False else (B.index s (i-1) == '\\') && not (escaped' (i-1)) + + +nested s = do ind <- match 0 0 + let (w,r) = B.splitAt ind s + return (NoSub (B.tail w), (B.tail r)) + where match !c !i + | B.length s <= i = fail $ "Couldn't match bracket" ++ show s + | otherwise = + case B.index s i of + '}' -> if c == 1 then return i else match (c-1) (i+1) + '{' -> match (c+1) (i+1) + _ -> match c (i+1) + +-- # TESTS # -- + +testNested = "Fail nested" ~: Nothing ~=? nested (bp " { the end") +testNested2 = "Pass nested" ~: Just (NoSub (bp " { }"), B.empty) ~=? nested (bp "{ { }}") +testNested3 = "Fail nested" ~: Nothing ~=? nested (bp " { { }") + +testEscaped = (escaped 1 (B.pack "\\\"")) ~? "pre-slashed quote should be escaped" +testEscaped2 = TestCase $ assertBool "non-slashed quote not escaped" (not (escaped 1 (B.pack " \""))) +testEscaped3 = TestCase $ assertBool "pre-slashed quote should be escaped" (escaped 2 (B.pack " \\\"")) +testEscaped4 = TestCase $ assertBool "non-slashed quote not escaped" (not (escaped 2 (B.pack " \""))) + +bp = B.pack +mklit = Word . bp +mkwd = Word . bp +testParseStr = "Escaped works" ~: Just (mklit "Oh \"yeah\" baby.", B.empty) ~=? parseStr (bp "\"Oh \\\"yeah\\\" baby.\"") +testParseStrLeft = "Parse Str with leftover" ~: Just (mklit "Hey there.", bp " 44") ~=? parseStr (bp "\"Hey there.\" 44") + +testGetInterp = "Escaped $ works" ~: Nothing ~=? getInterp (bp "a \\$variable") +testGetInterp2 = "unescaped $ works" ~: Just (bp "a ", mkwd "$variable", bp "") ~=? getInterp (bp "a $variable") +testGetInterp3 = "Escaped [" ~: Nothing ~=? getInterp (bp "a \\[sub] thing.") +testGetInterp4 = "Escaped []" ~: Nothing ~=? getInterp (bp "a \\[sub\\] thing.") +testGetInterp5 = "Escaped [] crazy" ~: + Just (bp "a ",Subcommand [mkwd "sub",mklit "quail [puts 1]"], bp " thing.") ~=? getInterp (bp "a [sub \"quail [puts 1]\"] thing.") +testGetInterp6 = "unescaped $ works" ~: Just (bp "a $", mkwd "$variable", bp "") ~=? getInterp (bp "a \\$$variable") + + +nestedTests= TestList [testNested, testNested2, testNested3] + + +getInterpTests = TestList [ testGetInterp, testGetInterp2, testGetInterp3, testGetInterp4, testGetInterp5, testGetInterp6 ] + + +tests = TestList [ nestedTests, testEscaped, testEscaped2, testEscaped3, testEscaped4, testParseStr, testParseStrLeft, + getInterpTests ] + +runUnit = runTestTT tests + +-- # ENDTESTS # -- diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,504 @@ + GNU LESSER GENERAL PUBLIC LICENSE + Version 2.1, February 1999 + + Copyright (C) 1991, 1999 Free Software Foundation, Inc. + 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + +[This is the first released version of the Lesser GPL. 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Here is a sample; alter the names: + + Yoyodyne, Inc., hereby disclaims all copyright interest in the + library `Frob' (a library for tweaking knobs) written by James Random Hacker. + + , 1 April 1990 + Ty Coon, President of Vice + +That's all there is to it! + + diff --git a/Main.hs b/Main.hs new file mode 100644 --- /dev/null +++ b/Main.hs @@ -0,0 +1,246 @@ +import Control.Monad.State +import qualified Data.Map as Map +import Control.Arrow +import System.IO +import Control.Monad.Error +import System.Exit +import Data.Char (toLower,toUpper) +import Data.List (intersperse) +import System.Environment +import Data.Maybe +import qualified Data.ByteString.Char8 as B +import BSParse + +type BString = B.ByteString + +data Err = ERet BString | EBreak | EContinue | EDie String deriving (Show,Eq) + +instance Error Err where + noMsg = EDie "An error occurred." + strMsg s = EDie s + +data TclEnv = TclEnv { vars :: VarMap, procs :: ProcMap, upMap :: Map.Map BString (Int,BString) } +type TclM = ErrorT Err (StateT [TclEnv] IO) +type TclProc = [BString] -> TclM RetVal +type ProcMap = Map.Map BString TclProc +type VarMap = Map.Map BString BString + +type RetVal = BString -- IGNORE + +procMap :: ProcMap +procMap = Map.fromList . map (B.pack *** id) $ + [("proc",procProc),("set",procSet),("upvar",procUpVar),("puts",procPuts),("gets",procGets), + ("uplevel", procUpLevel),("if",procIf),("while",procWhile),("eval", procEval),("exit",procExit), + ("list",procList),("lindex",procLindex),("llength",procLlength),("return",procReturn), + ("break",procRetv EBreak),("catch",procCatch),("continue",procRetv EContinue),("eq",procEq), + ("string", procString), ("append", procAppend), ("info", procInfo)] + ++ map (id *** procMath) [("+",(+)), ("*",(*)), ("-",(-)), ("/",div), ("<", toI (<)),("<=",toI (<=)),("==",toI (==)),("!=",toI (/=))] + +io :: IO a -> TclM a +io = liftIO + +toI :: (Int -> Int -> Bool) -> (Int -> Int -> Int) +toI n a b = if n a b then 1 else 0 + +baseEnv = TclEnv { vars = Map.empty, procs = procMap, upMap = Map.empty } + +main = do args <- getArgs + hSetBuffering stdout NoBuffering + case args of + [] -> run repl + [f] -> B.readFile f >>= run . doTcl + where run p = evalStateT (runErrorT (p `catchError` perr >> ret)) [baseEnv] >> return () + perr (EDie s) = io (hPutStrLn stderr s) >> ret + repl = do io (putStr "hiccup> ") + eof <- (io isEOF) + if eof then ret + else do ln <- procGets [] + if (not . B.null) ln then doTcl ln `catchError` perr >> repl else ret + +ret = return B.empty + +doTcl = runCmds . getParsed +runCmds = liftM last . mapM runCommand + +getParsed str = case runParse str of + Nothing -> error $ "parse error: " ++ (B.unpack str) + Just (v,r) -> filter (not . null) v + +doCond str = case getParsed str of + [x] -> runCommand x >>= return . isTrue + _ -> tclErr "Too many statements in conditional" + where isTrue = (/= B.pack "0") . trim + +trim = B.reverse . dropWhite . B.reverse . dropWhite + +withScope :: TclM RetVal -> TclM RetVal +withScope f = do + (o:old) <- get + put $ (baseEnv { procs = procs o }) : o : old + ret <- f + get >>= put . tail + return ret + +set :: BString -> BString -> TclM () +set str v = do env <- liftM head get + case upped str env of + Just (i,s) -> uplevel i (set s v) + Nothing -> do es <- liftM tail get + put ((env { vars = Map.insert str v (vars env) }):es) + +upped s e = Map.lookup s (upMap e) + +getProc str = get >>= return . Map.lookup str . procs . head +regProc name pr = modify (\(x:xs) -> (x { procs = Map.insert name pr (procs x) }):xs) >> ret + +evalw :: TclWord -> TclM RetVal +evalw (Word s) = interp s +evalw (NoSub s) = return s +evalw (Subcommand c) = runCommand c + +ptrace = False -- IGNORE + +runCommand :: [TclWord] -> TclM RetVal +runCommand [Subcommand s] = runCommand s +runCommand args = do + (name:evArgs) <- mapM evalw args + when ptrace $ io . print $ (name,args) -- IGNORE + proc <- getProc name + maybe (tclErr ("invalid command name: " ++ show name)) ($! evArgs) proc + +procProc, procSet, procPuts, procIf, procWhile, procReturn, procUpLevel :: TclProc +procSet [s1,s2] = set s1 s2 >> return s2 +procSet _ = tclErr $ "set: Wrong arg count" + +procPuts s@(sh:st) = (io . mapM_ puts) txt >> ret + where (puts,txt) = if sh == B.pack "-nonewline" then (B.putStr,st) else (B.putStrLn,s) +procPuts x = tclErr $ "Bad args to puts: " ++ show x + +procGets [] = io B.getLine >>= return +procGets _ = error "gets: Wrong arg count" + +procEq [a,b] = return . B.pack $ if a == b then "1" else "0" + +procMath :: (Int -> Int -> Int) -> TclProc +procMath op [s1,s2] = liftM2 op (parseInt s1) (parseInt s2) >>= return . B.pack . show +procMath op _ = tclErr "math: Wrong arg count" + +procEval [s] = doTcl s +procEval x = tclErr $ "Bad eval args: " ++ show x + +procExit [] = io (exitWith ExitSuccess) + +procCatch [s] = doTcl s `catchError` (const . return . B.pack) "0" + +procString (f:s:args) + | f == B.pack "trim" = return (trim s) + | f == B.pack "tolower" = return (B.map toLower s) + | f == B.pack "toupper" = return (B.map toUpper s) + | f == B.pack "length" = return . B.pack . show . B.length $ s + | f == B.pack "index" = case args of + [i] -> do ind <- parseInt i + if ind >= B.length s || ind < 0 then ret else return $ B.singleton (B.index s ind) + _ -> tclErr $ "Bad args to string index." + | otherwise = tclErr $ "Can't do string action: " ++ show f + +tclErr = throwError . EDie + +procInfo [x] = if x == B.pack "commands" then get >>= procList . Map.keys . procs . head + else tclErr $ "Unknown info command: " ++ show x + +procAppend (v:vx) = do val <- varGet v + procSet [v,B.concat (val:vx)] + +procList = return . B.concat . intersperse (B.singleton ' ') . map escape + where escape s = if B.elem ' ' s then B.concat [B.singleton '{', s, B.singleton '}'] else s + +procLindex [l,i] = do let items = map getDat . head . getParsed $ l + return . (!!) items =<< (parseInt i) + where getDat (Word s) = s + getDat (NoSub s) = s + getDat x = error $ "getDat doesn't understand: " ++ show x + +procLlength [lst] + | B.null lst = return (B.pack "0") + | otherwise = return . B.pack . show . length . head . getParsed $ lst +procLlength x = tclErr $ "Bad args to llength: " ++ show x + +procIf (cond:yes:rest) = do + condVal <- doCond cond + if condVal then doTcl yes + else case rest of + [s,blk] -> if s == B.pack "else" then doTcl blk else error "Invalid If" + (s:r) -> if s == B.pack "elseif" then procIf r else error "Invalid If" + [] -> ret +procIf x = tclErr "Not enough arguments to If." + +procWhile [cond,body] = loop `catchError` herr + where pbody = getParsed body + herr EBreak = ret + herr (ERet s) = return s + herr EContinue = loop `catchError` herr + herr x = throwError x + loop = do condVal <- doCond cond + if condVal then runCmds pbody >> loop else ret + +procReturn [s] = throwError (ERet s) +procRetv c [] = throwError c +procError [s] = tclErr (B.unpack s) + +parseInt si = maybe (tclErr ("Bad int: " ++ show si)) (return . fst) (B.readInt si) + +procUpLevel [p] = uplevel 1 (procEval [p]) +procUpLevel (si:p) = parseInt si >>= \i -> uplevel i (procEval p) + +uplevel i p = do + (curr,new) <- liftM (splitAt i) get + put new + res <- p + get >>= put . (curr ++) + return res + +procUpVar [s,d] = upvar 1 s d +procUpVar [si,s,d] = parseInt si >>= \i -> upvar i s d + +upvar n s d = do (e:es) <- get + put ((e { upMap = Map.insert s (n,d) (upMap e) }):es) + ret + +procProc [name,body] = regProc name (procRunner [] (getParsed body)) +procProc [name,args,body] = do + let params = case parseArgs args of + Nothing -> error "Parse failed." + Just (r,_) -> map to_s r + let pbody = getParsed body + regProc name (procRunner params pbody) + where to_s (Word b) = b + +procProc x = tclErr $ "proc: Wrong arg count (" ++ show (length x) ++ "): " ++ show x + + +procRunner :: [BString] -> [[TclWord]] -> [BString] -> TclM RetVal +procRunner pl body args = withScope $ do mapM_ (uncurry set) (zip pl args) + when ((not . null) pl && (last pl == B.pack "args")) $ do + val <- procList (drop ((length pl) - 1) args) + set (B.pack "args") val + runCmds body `catchError` herr + where herr (ERet s) = return s + herr x = error (show x) + +varGet name = do env <- liftM head get + case upped name env of + Nothing -> maybe (tclErr ("can't read \"$" ++ B.unpack name ++ "\": no such variable")) + return + (Map.lookup name (vars env)) + Just (i,n) -> uplevel i (varGet n) + + +interp :: BString -> TclM RetVal +interp str = case getInterp str of + Nothing -> return str + Just x -> handle x + where f (Word match) = varGet (B.tail match) + f x = runCommand [x] + handle (b,m,a) = do pre <- liftM (B.append b) (f m) + post <- interp a + return (B.append pre post) diff --git a/README b/README new file mode 100644 --- /dev/null +++ b/README @@ -0,0 +1,6 @@ +To get things a-going', do: + runhaskell Setup.lhs configure + runhaskell Setup.lhs build + + +I don't really recommend installing. Not too useful, and I've never tried it. diff --git a/Setup.lhs b/Setup.lhs new file mode 100644 --- /dev/null +++ b/Setup.lhs @@ -0,0 +1,3 @@ +#!/usr/bin/env runhaskell +> import Distribution.Simple +> main = defaultMain diff --git a/example.tcl b/example.tcl new file mode 100644 --- /dev/null +++ b/example.tcl @@ -0,0 +1,48 @@ +# Here is an example of some stuff hiccup can do. +# I think it's neat. + +proc incr v { + upvar 1 loc $v + set loc [+ $loc 1] +} + +proc decr v { + upvar loc $v + set loc [- $loc 1] +} + +proc memfib x { + set loc {1 1} + set ctr 2 + while { <= $ctr $x } { + set v1 [lindex $loc [- $ctr 1]] + set v2 [lindex $loc [- $ctr 2]] + set sum [+ $v1 $v2] + set loc "$loc $sum" + incr ctr + } + return [lindex $loc $x] +} + +set fcount 21 +puts "First $fcount fibonacci numbers in descending order:" +while {<= 2 $fcount} { + puts -nonewline "[memfib $fcount] " + decr fcount +} +puts "\nDone." + +proc foreach {vname lst what} { + set i 0 + while {< $i [llength $lst]} { + uplevel "set $vname [lindex $lst $i]" + uplevel $what + incr i + } +} + + +foreach name {Spain China Russia Argentina} { + puts "I've never been to $name." +} + diff --git a/hiccup.cabal b/hiccup.cabal new file mode 100644 --- /dev/null +++ b/hiccup.cabal @@ -0,0 +1,15 @@ +Name: hiccup +Version: 0.2 +Description: A simplistic interpreter for a subset of tcl +License: GPL +License-file: LICENSE +Author: Kyle Consalus +Maintainer: consalus+hiccup@google.com +Category: Compilers/Interpreters +Synopsis: Simple tcl interpeter +Build-Depends: base, HUnit, mtl +extra-source-files: BSParse.hs README example.tcl + +Executable: hiccup +Main-is: Main.hs +ghc-options: -O2 -fglasgow-exts -fbang-patterns -funbox-strict-fields diff --git a/hiccup.cabal~ b/hiccup.cabal~ new file mode 100644 --- /dev/null +++ b/hiccup.cabal~ @@ -0,0 +1,13 @@ +Name: hiccup +Version: 0.2 +Description: A simplistic interpreter for a subset of tcl +License: GPL +License-file: LICENSE +Author: Kyle Consalus +Maintainer: consalus+hiccup@google.com +Build-Depends: base, HUnit, mtl +extra-source-files: BSParse.hs README example.tcl + +Executable: hiccup +Main-is: Main.hs +ghc-options: -O2 -fglasgow-exts -fbang-patterns -funbox-strict-fields