{-# LANGUAGE GADTs #-}

{-# LANGUAGE ViewPatterns #-}

{-# LANGUAGE FlexibleContexts #-}

{-# LANGUAGE ScopedTypeVariables #-}

-- |

module Language.PureScript.CodeGen.JS

( module AST

, module Common

, moduleToJs

) where

import Prelude ()

import Prelude.Compat

import Data.List ((\\), delete, intersect)

import Data.Maybe (isNothing, fromMaybe)

import qualified Data.Map as M

import qualified Data.Foldable as F

import qualified Data.Traversable as T

import Control.Arrow ((&&&))

import Control.Monad (replicateM, forM, void)

import Control.Monad.Error.Class (MonadError(..))

import Control.Monad.Reader (MonadReader, asks)

import Control.Monad.Supply.Class

import Language.PureScript.Crash

import Language.PureScript.AST.SourcePos

import Language.PureScript.CodeGen.JS.AST as AST

import Language.PureScript.CodeGen.JS.Common as Common

import Language.PureScript.CoreFn

import Language.PureScript.Names

import Language.PureScript.Errors

import Language.PureScript.CodeGen.JS.Optimizer

import Language.PureScript.Options

import Language.PureScript.Traversals (sndM)

import qualified Language.PureScript.Constants as C

import System.FilePath.Posix ((</>))

-- |

moduleToJs

:: forall m

. (Applicative m, Monad m, MonadReader Options m, MonadSupply m, MonadError MultipleErrors m)

=> Module Ann

-> Maybe JS

-> m [JS]

moduleToJs (Module coms mn imps exps foreigns decls) foreign_ =

rethrow (addHint (ErrorInModule mn)) $ do

let usedNames = concatMap getNames decls

let mnLookup = renameImports usedNames imps

jsImports <- T.traverse (importToJs mnLookup) . delete (ModuleName [ProperName C.prim]) . (\\ [mn]) $ imps

let decls' = renameModules mnLookup decls

jsDecls <- mapM bindToJs decls'

optimized <- T.traverse (T.traverse optimize) jsDecls

F.traverse_ (F.traverse_ checkIntegers) optimized

comments <- not <$> asks optionsNoComments

let strict = JSStringLiteral "use strict"

let header = if comments && not (null coms) then JSComment coms strict else strict

let foreign' = [JSVariableIntroduction "$foreign" foreign_ | not $ null foreigns || isNothing foreign_]

let moduleBody = header : foreign' ++ jsImports ++ concat optimized

let foreignExps = exps `intersect` (fst `map` foreigns)

let standardExps = exps \\ foreignExps

let exps' = JSObjectLiteral $ map (runIdent &&& JSVar . identToJs) standardExps

++ map (runIdent &&& foreignIdent) foreignExps

return $ moduleBody ++ [JSAssignment (JSAccessor "exports" (JSVar "module")) exps']

where

-- |

-- Extracts all declaration names from a binding group.

--

getNames :: Bind Ann -> [Ident]

getNames (NonRec ident _) = [ident]

getNames (Rec vals) = map fst vals

-- |

-- Creates alternative names for each module to ensure they don't collide

-- with declaration names.

--

renameImports :: [Ident] -> [ModuleName] -> M.Map ModuleName ModuleName

renameImports ids mns = go M.empty ids mns

where

go :: M.Map ModuleName ModuleName -> [Ident] -> [ModuleName] -> M.Map ModuleName ModuleName

go acc used (mn' : mns') =

let mni = Ident $ runModuleName mn'

in if mni `elem` used

then let newName = freshModuleName 1 mn' used

in go (M.insert mn' newName acc) (Ident (runModuleName newName) : used) mns'

else go (M.insert mn' mn' acc) (mni : used) mns'

go acc _ [] = acc

freshModuleName :: Integer -> ModuleName -> [Ident] -> ModuleName

freshModuleName i mn'@(ModuleName pns) used =

let newName = ModuleName $ init pns ++ [ProperName $ runProperName (last pns) ++ "_" ++ show i]

in if Ident (runModuleName newName) `elem` used

then freshModuleName (i + 1) mn' used

else newName

-- |

-- Generates Javascript code for a module import, binding the required module

-- to the alternative

--

importToJs :: M.Map ModuleName ModuleName -> ModuleName -> m JS

importToJs mnLookup mn' = do

path <- asks optionsRequirePath

let mnSafe = fromMaybe (internalError "Missing value in mnLookup") $ M.lookup mn' mnLookup

let moduleBody = JSApp (JSVar "require") [JSStringLiteral (maybe id (</>) path $ runModuleName mn')]

return $ JSVariableIntroduction (moduleNameToJs mnSafe) (Just moduleBody)

-- |

-- Replaces the `ModuleName`s in the AST so that the generated code refers to

-- the collision-avoiding renamed module imports.

--

renameModules :: M.Map ModuleName ModuleName -> [Bind Ann] -> [Bind Ann]

renameModules mnLookup binds =

let (f, _, _) = everywhereOnValues id goExpr goBinder

in map f binds

where

goExpr :: Expr a -> Expr a

goExpr (Var ann q) = Var ann (renameQual q)

goExpr e = e

goBinder :: Binder a -> Binder a

goBinder (ConstructorBinder ann q1 q2 bs) = ConstructorBinder ann (renameQual q1) (renameQual q2) bs

goBinder b = b

renameQual :: Qualified a -> Qualified a

renameQual (Qualified (Just mn') a) =

let mnSafe = fromMaybe (internalError "Missing value in mnLookup") $ M.lookup mn' mnLookup

in Qualified (Just mnSafe) a

renameQual q = q

-- |

-- Generate code in the simplified Javascript intermediate representation for a declaration

--

bindToJs :: Bind Ann -> m [JS]

bindToJs (NonRec ident val) = return <$> nonRecToJS ident val

bindToJs (Rec vals) = forM vals (uncurry nonRecToJS)

-- |

-- Generate code in the simplified Javascript intermediate representation for a single non-recursive

-- declaration.

--

-- The main purpose of this function is to handle code generation for comments.

--

nonRecToJS :: Ident -> Expr Ann -> m JS

nonRecToJS i e@(extractAnn -> (_, com, _, _)) | not (null com) = do

withoutComment <- asks optionsNoComments

if withoutComment

then nonRecToJS i (modifyAnn removeComments e)

else JSComment com <$> nonRecToJS i (modifyAnn removeComments e)

nonRecToJS ident val = do

js <- valueToJs val

return $ JSVariableIntroduction (identToJs ident) (Just js)

-- |

-- Generate code in the simplified Javascript intermediate representation for a variable based on a

-- PureScript identifier.

--

var :: Ident -> JS

var = JSVar . identToJs

-- |

-- Generate code in the simplified Javascript intermediate representation for an accessor based on

-- a PureScript identifier. If the name is not valid in Javascript (symbol based, reserved name) an

-- indexer is returned.

--

accessor :: Ident -> JS -> JS

accessor (Ident prop) = accessorString prop

accessor (Op op) = JSIndexer (JSStringLiteral op)

accessor (GenIdent _ _) = internalError "GenIdent in accessor"

accessorString :: String -> JS -> JS

accessorString prop | identNeedsEscaping prop = JSIndexer (JSStringLiteral prop)

| otherwise = JSAccessor prop

-- |

-- Generate code in the simplified Javascript intermediate representation for a value or expression.

--

valueToJs :: Expr Ann -> m JS

valueToJs (Literal (pos, _, _, _) l) =

maybe id rethrowWithPosition pos $ literalToValueJS l

valueToJs (Var (_, _, _, Just (IsConstructor _ [])) name) =

return $ JSAccessor "value" $ qualifiedToJS id name

valueToJs (Var (_, _, _, Just (IsConstructor _ _)) name) =

return $ JSAccessor "create" $ qualifiedToJS id name

valueToJs (Accessor _ prop val) =

accessorString prop <$> valueToJs val

valueToJs (ObjectUpdate _ o ps) = do

obj <- valueToJs o

sts <- mapM (sndM valueToJs) ps

extendObj obj sts

valueToJs e@(Abs (_, _, _, Just IsTypeClassConstructor) _ _) =

let args = unAbs e

in return $ JSFunction Nothing (map identToJs args) (JSBlock $ map assign args)

where

unAbs :: Expr Ann -> [Ident]

unAbs (Abs _ arg val) = arg : unAbs val

unAbs _ = []

assign :: Ident -> JS

assign name = JSAssignment (accessorString (runIdent name) (JSVar "this"))

(var name)

valueToJs (Abs _ arg val) = do

ret <- valueToJs val

return $ JSFunction Nothing [identToJs arg] (JSBlock [JSReturn ret])

valueToJs e@App{} = do

let (f, args) = unApp e []

args' <- mapM valueToJs args

case f of

Var (_, _, _, Just IsNewtype) _ -> return (head args')

Var (_, _, _, Just (IsConstructor _ fields)) name | length args == length fields ->

return $ JSUnary JSNew $ JSApp (qualifiedToJS id name) args'

Var (_, _, _, Just IsTypeClassConstructor) name ->

return $ JSUnary JSNew $ JSApp (qualifiedToJS id name) args'

_ -> flip (foldl (\fn a -> JSApp fn [a])) args' <$> valueToJs f

where

unApp :: Expr Ann -> [Expr Ann] -> (Expr Ann, [Expr Ann])

unApp (App _ val arg) args = unApp val (arg : args)

unApp other args = (other, args)

valueToJs (Var (_, _, _, Just IsForeign) qi@(Qualified (Just mn') ident)) =

return $ if mn' == mn

then foreignIdent ident

else varToJs qi

valueToJs (Var (_, _, _, Just IsForeign) ident) =

error $ "Encountered an unqualified reference to a foreign ident " ++ showQualified showIdent ident

valueToJs (Var _ ident) =

return $ varToJs ident

valueToJs (Case (maybeSpan, _, _, _) values binders) = do

vals <- mapM valueToJs values

bindersToJs maybeSpan binders vals

valueToJs (Let _ ds val) = do

ds' <- concat <$> mapM bindToJs ds

ret <- valueToJs val

return $ JSApp (JSFunction Nothing [] (JSBlock (ds' ++ [JSReturn ret]))) []

valueToJs (Constructor (_, _, _, Just IsNewtype) _ (ProperName ctor) _) =

return $ JSVariableIntroduction ctor (Just $

JSObjectLiteral [("create",

JSFunction Nothing ["value"]

(JSBlock [JSReturn $ JSVar "value"]))])

valueToJs (Constructor _ _ (ProperName ctor) []) =

return $ iife ctor [ JSFunction (Just ctor) [] (JSBlock [])

, JSAssignment (JSAccessor "value" (JSVar ctor))

(JSUnary JSNew $ JSApp (JSVar ctor) []) ]

valueToJs (Constructor _ _ (ProperName ctor) fields) =

let constructor =

let body = [ JSAssignment (JSAccessor (identToJs f) (JSVar "this")) (var f) | f <- fields ]

in JSFunction (Just ctor) (identToJs `map` fields) (JSBlock body)

createFn =

let body = JSUnary JSNew $ JSApp (JSVar ctor) (var `map` fields)

in foldr (\f inner -> JSFunction Nothing [identToJs f] (JSBlock [JSReturn inner])) body fields

in return $ iife ctor [ constructor

, JSAssignment (JSAccessor "create" (JSVar ctor)) createFn

]

iife :: String -> [JS] -> JS

iife v exprs = JSApp (JSFunction Nothing [] (JSBlock $ exprs ++ [JSReturn $ JSVar v])) []

literalToValueJS :: Literal (Expr Ann) -> m JS

literalToValueJS (NumericLiteral (Left i)) = return $ JSNumericLiteral (Left i)

literalToValueJS (NumericLiteral (Right n)) = return $ JSNumericLiteral (Right n)

literalToValueJS (StringLiteral s) = return $ JSStringLiteral s

literalToValueJS (CharLiteral c) = return $ JSStringLiteral [c]

literalToValueJS (BooleanLiteral b) = return $ JSBooleanLiteral b

literalToValueJS (ArrayLiteral xs) = JSArrayLiteral <$> mapM valueToJs xs

literalToValueJS (ObjectLiteral ps) = JSObjectLiteral <$> mapM (sndM valueToJs) ps

-- |

-- Shallow copy an object.

--

extendObj :: JS -> [(String, JS)] -> m JS

extendObj obj sts = do

newObj <- freshName

key <- freshName

let

jsKey = JSVar key

jsNewObj = JSVar newObj

block = JSBlock (objAssign:copy:extend ++ [JSReturn jsNewObj])

objAssign = JSVariableIntroduction newObj (Just $ JSObjectLiteral [])

copy = JSForIn key obj $ JSBlock [JSIfElse cond assign Nothing]

cond = JSApp (JSAccessor "hasOwnProperty" obj) [jsKey]

assign = JSBlock [JSAssignment (JSIndexer jsKey jsNewObj) (JSIndexer jsKey obj)]

stToAssign (s, js) = JSAssignment (JSAccessor s jsNewObj) js

extend = map stToAssign sts

return $ JSApp (JSFunction Nothing [] block) []

-- |

-- Generate code in the simplified Javascript intermediate representation for a reference to a

-- variable.

--

varToJs :: Qualified Ident -> JS

varToJs (Qualified Nothing ident) = var ident

varToJs qual = qualifiedToJS id qual

-- |

-- Generate code in the simplified Javascript intermediate representation for a reference to a

-- variable that may have a qualified name.

--

qualifiedToJS :: (a -> Ident) -> Qualified a -> JS

qualifiedToJS f (Qualified (Just (ModuleName [ProperName mn'])) a) | mn' == C.prim = JSVar . runIdent $ f a

qualifiedToJS f (Qualified (Just mn') a) | mn /= mn' = accessor (f a) (JSVar (moduleNameToJs mn'))

qualifiedToJS f (Qualified _ a) = JSVar $ identToJs (f a)

foreignIdent :: Ident -> JS

foreignIdent ident = accessorString (runIdent ident) (JSVar "$foreign")

-- |

-- Generate code in the simplified Javascript intermediate representation for pattern match binders

-- and guards.

--

bindersToJs :: Maybe SourceSpan -> [CaseAlternative Ann] -> [JS] -> m JS

bindersToJs maybeSpan binders vals = do

valNames <- replicateM (length vals) freshName

let assignments = zipWith JSVariableIntroduction valNames (map Just vals)

jss <- forM binders $ \(CaseAlternative bs result) -> do

ret <- guardsToJs result

go valNames ret bs

return $ JSApp (JSFunction Nothing [] (JSBlock (assignments ++ concat jss ++ [JSThrow $ failedPatternError valNames])))

[]

where

go :: [String] -> [JS] -> [Binder Ann] -> m [JS]

go _ done [] = return done

go (v:vs) done' (b:bs) = do

done'' <- go vs done' bs

binderToJs v done'' b

go _ _ _ = internalError "Invalid arguments to bindersToJs"

failedPatternError :: [String] -> JS

failedPatternError names = JSUnary JSNew $ JSApp (JSVar "Error") [JSBinary Add (JSStringLiteral failedPatternMessage) (JSArrayLiteral $ zipWith valueError names vals)]

failedPatternMessage :: String

failedPatternMessage = "Failed pattern match" ++ maybe "" (((" at " ++ runModuleName mn ++ " ") ++) . displayStartEndPos) maybeSpan ++ ": "

valueError :: String -> JS -> JS

valueError _ l@(JSNumericLiteral _) = l

valueError _ l@(JSStringLiteral _) = l

valueError _ l@(JSBooleanLiteral _) = l

valueError s _ = JSAccessor "name" . JSAccessor "constructor" $ JSVar s

guardsToJs :: Either [(Guard Ann, Expr Ann)] (Expr Ann) -> m [JS]

guardsToJs (Left gs) = forM gs $ \(cond, val) -> do

cond' <- valueToJs cond

done <- valueToJs val

return $ JSIfElse cond' (JSBlock [JSReturn done]) Nothing

guardsToJs (Right v) = return . JSReturn <$> valueToJs v

-- |

-- Generate code in the simplified Javascript intermediate representation for a pattern match

-- binder.

--

binderToJs :: String -> [JS] -> Binder Ann -> m [JS]

binderToJs _ done (NullBinder{}) = return done

binderToJs varName done (LiteralBinder _ l) =

literalToBinderJS varName done l

binderToJs varName done (VarBinder _ ident) =

return (JSVariableIntroduction (identToJs ident) (Just (JSVar varName)) : done)

binderToJs varName done (ConstructorBinder (_, _, _, Just IsNewtype) _ _ [b]) =

binderToJs varName done b

binderToJs varName done (ConstructorBinder (_, _, _, Just (IsConstructor ctorType fields)) _ ctor bs) = do

js <- go (zip fields bs) done

return $ case ctorType of

ProductType -> js

SumType ->

[JSIfElse (JSInstanceOf (JSVar varName) (qualifiedToJS (Ident . runProperName) ctor))

(JSBlock js)

Nothing]

where

go :: [(Ident, Binder Ann)] -> [JS] -> m [JS]

go [] done' = return done'

go ((field, binder) : remain) done' = do

argVar <- freshName

done'' <- go remain done'

js <- binderToJs argVar done'' binder

return (JSVariableIntroduction argVar (Just (JSAccessor (identToJs field) (JSVar varName))) : js)

binderToJs _ _ ConstructorBinder{} =

internalError "binderToJs: Invalid ConstructorBinder in binderToJs"

binderToJs varName done (NamedBinder _ ident binder) = do

js <- binderToJs varName done binder

return (JSVariableIntroduction (identToJs ident) (Just (JSVar varName)) : js)

literalToBinderJS :: String -> [JS] -> Literal (Binder Ann) -> m [JS]

literalToBinderJS varName done (NumericLiteral num) =

return [JSIfElse (JSBinary EqualTo (JSVar varName) (JSNumericLiteral num)) (JSBlock done) Nothing]

literalToBinderJS varName done (CharLiteral c) =

return [JSIfElse (JSBinary EqualTo (JSVar varName) (JSStringLiteral [c])) (JSBlock done) Nothing]

literalToBinderJS varName done (StringLiteral str) =

return [JSIfElse (JSBinary EqualTo (JSVar varName) (JSStringLiteral str)) (JSBlock done) Nothing]

literalToBinderJS varName done (BooleanLiteral True) =

return [JSIfElse (JSVar varName) (JSBlock done) Nothing]

literalToBinderJS varName done (BooleanLiteral False) =

return [JSIfElse (JSUnary Not (JSVar varName)) (JSBlock done) Nothing]

literalToBinderJS varName done (ObjectLiteral bs) = go done bs

where

go :: [JS] -> [(String, Binder Ann)] -> m [JS]

go done' [] = return done'

go done' ((prop, binder):bs') = do

propVar <- freshName

done'' <- go done' bs'

js <- binderToJs propVar done'' binder

return (JSVariableIntroduction propVar (Just (accessorString prop (JSVar varName))) : js)

literalToBinderJS varName done (ArrayLiteral bs) = do

js <- go done 0 bs

return [JSIfElse (JSBinary EqualTo (JSAccessor "length" (JSVar varName)) (JSNumericLiteral (Left (fromIntegral $ length bs)))) (JSBlock js) Nothing]

where

go :: [JS] -> Integer -> [Binder Ann] -> m [JS]

go done' _ [] = return done'

go done' index (binder:bs') = do

elVar <- freshName

done'' <- go done' (index + 1) bs'

js <- binderToJs elVar done'' binder

return (JSVariableIntroduction elVar (Just (JSIndexer (JSNumericLiteral (Left index)) (JSVar varName))) : js)

-- Check that all integers fall within the valid int range for JavaScript.

checkIntegers :: JS -> m ()

checkIntegers = void . everywhereOnJSTopDownM go

where

go :: JS -> m JS

go (JSUnary Negate (JSNumericLiteral (Left i))) =

-- Move the negation inside the literal; since this is a top-down

-- traversal doing this replacement will stop the next case from raising

-- the error when attempting to use -2147483648, as if left unrewritten

-- the value is `JSUnary Negate (JSNumericLiteral (Left 2147483648))`, and

-- 2147483648 is larger than the maximum allowed int.

return $ JSNumericLiteral (Left (-i))

go js@(JSNumericLiteral (Left i)) =

let minInt = -2147483648

maxInt = 2147483647

in if i < minInt || i > maxInt

then throwError . errorMessage $ IntOutOfRange i "JavaScript" minInt maxInt

else return js

go other = return other