elm/compiler/Gen/CompileToJS.hs
2013-06-03 19:44:45 +12:00

341 lines
No EOL
13 KiB
Haskell

module CompileToJS (showErr, jsModule) where
import Control.Arrow (first,second)
import Control.Monad (liftM,(<=<),join,ap)
import Data.Char (isAlpha,isDigit)
import Data.List (intercalate,sortBy,inits,foldl')
import qualified Data.Map as Map
import Data.Either (partitionEithers)
import qualified Text.Pandoc as Pan
import Data.Maybe (maybeToList)
import Ast
import Located
import Rename (derename)
import Cases
import Guid
import Rename (deprime)
import Types.Types ( Type(RecordT) )
showErr :: String -> String
showErr err = globalAssign "Elm.Main" (jsFunc "elm" body)
where msg = show . concatMap (++"<br>") . lines $ err
body = "var T = Elm.Text(elm);\n\
\return { main : T.text(T.monospace(" ++ msg ++ ")) };"
indent = concatMap f
where f '\n' = "\n "
f c = [c]
internalImports =
[ ("N" , "Elm.Native"),
("_N", "N.Utils(elm)"),
("_L", "N.List(elm)"),
("_E", "N.Error(elm)"),
("_str", "N.JavaScript(elm).toString")
]
parens s = "(" ++ s ++ ")"
brackets s = "{" ++ s ++ "}"
jsObj = brackets . intercalate ", "
jsList ss = "["++ intercalate "," ss ++"]"
jsFunc args body = "function(" ++ args ++ "){" ++ indent body ++ "}"
assign x e = "\nvar " ++ x ++ " = " ++ e ++ ";"
ret e = "\nreturn "++ e ++";"
iff a b c = a ++ "?" ++ b ++ ":" ++ c
quoted s = "'" ++ concatMap f s ++ "'"
where f '\n' = "\\n"
f '\'' = "\\'"
f '\t' = "\\t"
f '\"' = "\\\""
f '\\' = "\\\\"
f c = [c]
globalAssign n e = "\n" ++ assign' n e ++ ";"
assign' n e = n ++ " = " ++ e
jsModule (Module names exports imports stmts) =
setup ("Elm":modNames) ++ globalAssign ("Elm." ++ modName) (jsFunc "elm" program)
where
modNames = if null names then ["Main"] else names
modName = intercalate "." modNames
includes = concatMap jsImport imports
body = stmtsToJS stmts
defs = assign "$op" "{}"
program = "\nvar " ++ usefulFuncs ++ ";" ++ defs ++ includes ++ body ++
setup ("elm":"Native":modNames) ++
assign "_" ("elm.Native." ++ modName ++ "||{}") ++
getExports exports stmts ++ setup ("elm":modNames) ++
ret (assign' ("elm." ++ modName) "_") ++ "\n"
setup modNames = concatMap (\n -> globalAssign n $ n ++ "||{}") .
map (intercalate ".") . drop 2 . inits $ init modNames
usefulFuncs = intercalate ", " (map (uncurry assign') internalImports)
getExports names stmts = "\n"++ intercalate ";\n" (op : map fnPair fns)
where exNames n = either derename id n `elem` names
exports | null names = concatMap get stmts
| otherwise = filter exNames (concatMap get stmts)
(fns,ops) = partitionEithers exports
opPair op = "'" ++ op ++ "' : $op['" ++ op ++ "']"
fnPair fn = let fn' = derename fn in "_." ++ fn' ++ " = " ++ fn
op = ("_.$op = "++) . jsObj $ map opPair ops
get' (FnDef x _ _) = Just (Left x)
get' (OpDef op _ _ _) = Just (Right op)
get' (TypeAnnotation _ _) = Nothing
get s = case s of Definition d -> maybeToList (get' d)
Datatype _ _ tcs -> map (Left . fst) tcs
ImportEvent _ _ x _ -> [ Left x ]
ExportEvent _ _ _ -> []
TypeAlias _ _ _ -> []
jsImport (modul, how) =
case how of
As name -> assign name ("Elm." ++ modul ++ parens "elm")
Hiding vs -> include ++ " var hiding=" ++ (jsObj $ map (++":1") vs) ++
"; for(var k in _){if(k in hiding)continue;" ++
"eval('var '+k+'=_[\"'+k+'\"]')}"
Importing vs -> include ++ named
where
imprt v = assign' v ("_." ++ v)
def (o:p) = imprt (if isOp o then "$op['" ++ o:p ++ "']" else deprime (o:p))
named = if null vs then "" else "\nvar " ++ intercalate ", " (map def vs) ++ ";"
where
include = "\nvar _ = Elm." ++ modul ++ parens "elm" ++ ";" ++ setup modul
setup moduleName = " var " ++ concatMap (++";") (defs ++ [assign' moduleName "_"])
where
defs = map (\n -> assign' n (n ++ "||{}")) (subnames moduleName)
subnames = map (intercalate ".") . tail . inits . init . split
split names = case go [] names of
(name, []) -> [name]
(name, ns) -> name : split ns
go name str = case str of
'.':rest -> (reverse name, rest)
c:rest -> go (c:name) rest
[] -> (reverse name, [])
stmtsToJS :: [Statement] -> String
stmtsToJS stmts = run $ do program <- mapM toJS (sortBy cmpStmt stmts)
return (concat program)
where
cmpStmt s1 s2 = compare (valueOf s1) (valueOf s2)
valueOf s = case s of
Datatype _ _ _ -> 1
ImportEvent _ _ _ _ -> 2
Definition (FnDef f [] _) ->
if derename f == "main" then 5 else 4
Definition (TypeAnnotation _ _) -> 0
Definition _ -> 3
ExportEvent _ _ _ -> 6
TypeAlias _ _ _ -> 0
class ToJS a where
toJS :: a -> GuidCounter String
instance ToJS Def where
toJS (FnDef x [] e) = assign x `liftM` toJS' e
toJS (FnDef f as e) = (assign f . wrapper . func) `liftM` toJS' e
where
func body = jsFunc (intercalate ", " as) (ret body)
wrapper e | length as == 1 = e
| otherwise = 'F' : show (length as) ++ parens e
toJS (OpDef op a1 a2 e) =
do body <- toJS' e
let func = "F2" ++ parens (jsFunc (a1 ++ ", " ++ a2) (ret body))
return (globalAssign ("$op['" ++ op ++ "']") func)
toJS (TypeAnnotation _ _) = return ""
instance ToJS Statement where
toJS stmt =
case stmt of
Definition d -> toJS d
Datatype _ _ tcs -> concat `liftM` mapM (toJS . toDef) tcs
where toDef (name,args) =
let vars = map (('a':) . show) [1..length args] in
Definition . FnDef name vars . notLocated $
Data (derename name) (map (notLocated . Var) vars)
ImportEvent js base elm _ ->
do v <- toJS' base
return $ concat [ "\nvar " ++ elm ++ "=Elm.Signal(elm).constant(" ++ v ++ ");"
, "\ndocument.addEventListener('", js
, "_' + elm.id, function(e) { elm.notify(", elm
, ".id, e.value); });" ]
ExportEvent js elm _ ->
return $ concat [ "\nlift(function(v) { "
, "var e = document.createEvent('Event');"
, "e.initEvent('", js, "_' + elm.id, true, true);"
, "e.value = v;"
, "document.dispatchEvent(e); return v; })(", elm, ");" ]
TypeAlias n _ t -> return ""
toJS' :: CExpr -> GuidCounter String
toJS' (L txt span expr) =
case expr of
MultiIf ps -> multiIfToJS span ps
Case e cases -> caseToJS span e cases
_ -> toJS expr
remove x e = "_N.remove('" ++ x ++ "', " ++ e ++ ")"
addField x v e = "_N.insert('" ++ x ++ "', " ++ v ++ ", " ++ e ++ ")"
setField fs e = "_N.replace(" ++ jsList (map f fs) ++ ", " ++ e ++ ")"
where f (x,v) = "['" ++ x ++ "'," ++ v ++ "]"
access x e = e ++ "." ++ x
makeRecord kvs = record `liftM` collect kvs
where
combine r (k,v) = Map.insertWith (++) k v r
collect = liftM (foldl' combine Map.empty) . mapM prep
prep (k, as, e@(L t s _)) =
do v <- toJS' (foldr (\x e -> L t s $ Lambda x e) e as)
return (k,[v])
fields fs =
brackets ("\n "++intercalate ",\n " (map (\(k,v) -> k++":"++v) fs))
hidden = fields . map (second jsList) .
filter (not . null . snd) . Map.toList . Map.map tail
record kvs = fields . (("_", hidden kvs) :) . Map.toList . Map.map head $ kvs
instance ToJS Expr where
toJS expr =
case expr of
Var x -> return $ x
Chr c -> return $ quoted [c]
Str s -> return $ "_str" ++ parens (quoted s)
IntNum n -> return $ show n
FloatNum n -> return $ show n
Boolean b -> return $ if b then "true" else "false"
Range lo hi -> jsRange `liftM` toJS' lo `ap` toJS' hi
Access e x -> access x `liftM` toJS' e
Remove e x -> remove x `liftM` toJS' e
Insert e x v -> addField x `liftM` toJS' v `ap` toJS' e
Modify e fs -> do fs' <- (mapM (\(x,v) -> (,) x `liftM` toJS' v) fs)
setField fs' `liftM` toJS' e
Record fs -> makeRecord fs
Binop op e1 e2 -> binop op `liftM` toJS' e1 `ap` toJS' e2
If eb et ef ->
parens `liftM` (iff `liftM` toJS' eb `ap` toJS' et `ap` toJS' ef)
Lambda v e -> liftM (jsFunc v . ret) (toJS' e)
App e1 e2 -> jsApp e1 e2
Let defs e -> jsLet defs e
Data name es ->
do fs <- mapM toJS' es
return $ case name of
"Nil" -> jsNil
"Cons" -> jsCons (head fs) ((head . tail) fs)
_ -> jsObj $ ("ctor:" ++ show name) : fields
where fields = zipWith (\n e -> "_" ++ show n ++ ":" ++ e) [0..] fs
Markdown doc -> return $ "text('" ++ pad ++ md ++ pad ++ "')"
where pad = "<div style=\"height:0;width:0;\">&nbsp;</div>"
md = formatMarkdown $ Pan.writeHtmlString Pan.def doc
jsApp e1 e2 =
do f <- toJS' func
as <- mapM toJS' args
return $ case as of
[a] -> f ++ parens a
_ -> "A" ++ show (length as) ++ parens (intercalate ", " (f:as))
where
(func, args) = go [e2] e1
go args e =
case e of
(L _ _ (App e1 e2)) -> go (e2 : args) e1
_ -> (e, args)
formatMarkdown = concatMap f
where f '\'' = "\\'"
f '\n' = "\\n"
f '"' = "\""
f c = [c]
multiIfToJS span ps =
case last ps of
(L _ _ (Var "otherwise"), e) -> toJS' e >>= \b -> format b (init ps)
_ -> format ("_E.If" ++ parens (quoted (show span))) ps
where
format base ps =
foldr (\c e -> parens $ c ++ " : " ++ e) base `liftM` mapM f ps
f (b,e) = do b' <- toJS' b
e' <- toJS' e
return (b' ++ " ? " ++ e')
jsLet defs e' = do ds <- jsDefs defs
e <- toJS' e'
return $ jsFunc "" (concat ds ++ ret e) ++ "()"
where
jsDefs defs = mapM toJS (sortBy f defs)
f a b = compare (valueOf a) (valueOf b)
valueOf (FnDef _ [] _) = 2
valueOf (FnDef _ _ _) = 1
valueOf (OpDef _ _ _ _) = 1
valueOf (TypeAnnotation _ _) = 0
caseToJS span e ps = do
match <- caseToMatch ps
e' <- toJS' e
let (match',stmt) = case (match,e) of
(Match name _ _, L _ _ (Var x)) -> (matchSubst [(name,x)] match, "")
(Match name _ _, _) -> (match, assign name e')
_ -> (match, "")
matches <- matchToJS span match'
return $ "function(){ " ++ stmt ++ matches ++ " }()"
matchToJS span match =
case match of
Match name clauses def ->
do cases <- concat `liftM` mapM (clauseToJS span name) clauses
finally <- matchToJS span def
return $ concat [ "\nswitch (", name, ".ctor) {",
indent cases, "\n}", finally ]
Fail -> return ("_E.Case" ++ parens (quoted (show span)))
Break -> return "break;"
Other e -> ret `liftM` toJS' e
Seq ms -> concat `liftM` mapM (matchToJS span) (dropEnd [] ms)
where
dropEnd acc [] = acc
dropEnd acc (m:ms) =
case m of
Other _ -> acc ++ [m]
_ -> dropEnd (acc ++ [m]) ms
clauseToJS span var (Clause name vars e) = do
let vars' = map (\n -> var ++ "._" ++ show n) [0..]
s <- matchToJS span $ matchSubst (zip vars vars') e
return $ concat [ "\ncase ", quoted name, ":", indent s ]
jsNil = "_L.Nil"
jsCons e1 e2 = "_L.Cons(" ++ e1 ++ "," ++ e2 ++ ")"
jsRange e1 e2 = "_L.range" ++ parens (e1 ++ "," ++ e2)
jsCompare e1 e2 op = parens ("_N.cmp(" ++ e1 ++ "," ++ e2 ++ ").ctor" ++ op)
binop (o:p) e1 e2
| isAlpha o || '_' == o = (o:p) ++ parens e1 ++ parens e2
| otherwise =
let ops = ["+","-","*","/","&&","||"] in
case o:p of
"::" -> jsCons e1 e2
"++" -> "_L.append" ++ parens (e1 ++ "," ++ e2)
"<|" -> e1 ++ parens e2
"|>" -> e2 ++ parens e1
"." -> jsFunc "x" . ret $ e1 ++ parens (e2 ++ parens "x")
"^" -> "Math.pow(" ++ e1 ++ "," ++ e2 ++ ")"
"==" -> "_N.eq(" ++ e1 ++ "," ++ e2 ++ ")"
"/=" -> "!_N.eq(" ++ e1 ++ "," ++ e2 ++ ")"
"<" -> jsCompare e1 e2 "==='LT'"
">" -> jsCompare e1 e2 "==='GT'"
"<=" -> jsCompare e1 e2 "!=='GT'"
">=" -> jsCompare e1 e2 "!=='LT'"
"<~" -> "A2(lift," ++ e1 ++ "," ++ e2 ++ ")"
"~" -> "A3(lift2,F2(function(f,x){return f(x)}),"++e1++","++e2++")"
_ | elem (o:p) ops -> parens (e1 ++ (o:p) ++ e2)
| otherwise -> concat [ "$op['", o:p, "']"
, parens e1, parens e2 ]