git.iko.soy/rowtype-yoga/purescript-native
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rowtype-yoga/purescript-native/src/PureScript/CodeGen/JS.hs
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1-----------------------------------------------------------------------------
2--
3-- Module : PureScript.CodeGen.JS
4-- Copyright : (c) Phil Freeman 2013
5-- License : MIT
6--
7-- Maintainer : Phil Freeman <paf31@cantab.net>
8-- Stability : experimental
9-- Portability :
10--
11-- |
12--
13-----------------------------------------------------------------------------
15module PureScript.CodeGen.JS (
16 declToJs
17) where
19import Data.Char
20import Data.Maybe (fromMaybe)
21import Data.List (intercalate)
22import qualified Control.Arrow as A
23import Control.Arrow ((<+>))
24import Control.Applicative
26import PureScript.Types
27import PureScript.Values
28import PureScript.Names
29import PureScript.Declarations
30import PureScript.CodeGen.Common
31import PureScript.CodeGen.Common.Gen
33declToJs :: Declaration -> Maybe String
34declToJs (ValueDeclaration ident (Abs args ret)) = Just $ "function " ++ identToJs ident ++ "(" ++ intercalate "," (map identToJs args) ++ ") { return " ++ valueToJs ret ++ "; }"
35declToJs (ValueDeclaration ident val) = Just $ "var " ++ identToJs ident ++ " = " ++ valueToJs val ++ ";"
36declToJs (DataDeclaration _ _ ctors) =
37 Just $ flip concatMap ctors $ \(ctor, maybeTy) ->
38 case maybeTy of
39 Nothing -> "var " ++ ctor ++ " = { ctor: '" ++ ctor ++ "' };"
40 Just _ -> "var " ++ ctor ++ " = function (value) { return { ctor: '" ++ ctor ++ "', value: value }; };"
41declToJs _ = Nothing
43literals :: Pattern Value String
44literals = Pattern $ A.Kleisli match
45 where
46 match (NumericLiteral n) = Just $ either show show n
47 match (StringLiteral s) = Just $ show s
48 match (BooleanLiteral True) = Just "true"
49 match (BooleanLiteral False) = Just "false"
50 match (ArrayLiteral xs) = Just $ "[" ++ intercalate "," (map valueToJs xs) ++ "]"
51 match (ObjectLiteral ps) = Just $ "{" ++ intercalate "," (map objectPropertyToJs ps) ++ "}"
52 match (ObjectUpdate o ps) = Just $ "Object.extend("
53 ++ valueToJs o ++ ", { "
54 ++ intercalate ", " (map objectPropertyToJs ps) ++ " }"
55 match (Constructor name) = Just name
56 match (Block sts) = Just $ "(function () {" ++ intercalate ";" (map statementToJs sts) ++ "})()"
57 match (Case value binders) = Just $ "(" ++ runGen (bindersToJs binders) ++ ")(" ++ valueToJs value ++ ")"
58 where
59 bindersToJs :: [(Binder, Value)] -> Gen String
60 bindersToJs binders = do
61 valName <- fresh
62 jss <- flip mapM binders $ \(binder, result) -> do
63 let js = valueToJs result
64 binderToJs valName ("return " ++ js ++ ";") binder
65 return $ "function (" ++ valName ++ ") {" ++ concat jss ++ "throw \"Failed pattern match\"; }"
66 match (Var ident) = Just (identToJs ident)
67 match _ = Nothing
69ifThenElse :: Pattern Value ((Value, Value), Value)
70ifThenElse = Pattern $ A.Kleisli match
71 where
72 match (IfThenElse cond th el) = Just ((th, el), cond)
73 match _ = Nothing
75accessor :: Pattern Value (String, Value)
76accessor = Pattern $ A.Kleisli match
77 where
78 match (Accessor prop val) = Just (prop, val)
79 match _ = Nothing
81indexer :: Pattern Value (String, Value)
82indexer = Pattern $ A.Kleisli match
83 where
84 match (Indexer index val) = Just (valueToJs index, val)
85 match _ = Nothing
87app :: Pattern Value (String, Value)
88app = Pattern $ A.Kleisli match
89 where
90 match (App val args) = Just (intercalate "," (map valueToJs args), val)
91 match _ = Nothing
93lam :: Pattern Value ([String], Value)
94lam = Pattern $ A.Kleisli match
95 where
96 match (Abs args val) = Just (map identToJs args, val)
97 match _ = Nothing
99unary :: UnaryOperator -> String -> Operator Value String
100unary op str = Wrap pattern (++)
101 where
102 pattern :: Pattern Value (String, Value)
103 pattern = Pattern $ A.Kleisli match
104 where
105 match (Unary op' val) | op' == op = Just (str, val)
106 match _ = Nothing
108binary :: BinaryOperator -> String -> Operator Value String
109binary op str = AssocR pattern (\v1 v2 -> v1 ++ " " ++ str ++ " " ++ v2)
110 where
111 pattern :: Pattern Value (Value, Value)
112 pattern = Pattern $ A.Kleisli match
113 where
114 match (Binary op' v1 v2) | op' == op = Just (v1, v2)
115 match _ = Nothing
117valueToJs :: Value -> String
118valueToJs = fromMaybe (error "Incomplete pattern") . pattern matchValue
119 where
120 matchValue :: Pattern Value String
121 matchValue = buildPrettyPrinter operators (literals <+> fmap parens matchValue)
122 operators :: OperatorTable Value String
123 operators =
124 OperatorTable $ [ [ Wrap accessor $ \prop val -> val ++ "." ++ prop ]
125 , [ Wrap indexer $ \index val -> val ++ "[" ++ index ++ "]" ]
126 , [ Wrap app $ \args val -> val ++ "(" ++ args ++ ")" ]
127 , [ Split lam $ \args val -> "function (" ++ intercalate "," args ++ ") { return " ++ valueToJs val ++ "; }" ]
128 , [ Wrap ifThenElse $ \(th, el) cond -> cond ++ " ? " ++ valueToJs th ++ " : " ++ valueToJs el ]
129 , [ binary LessThan "<" ]
130 , [ binary LessThanOrEqualTo "<=" ]
131 , [ binary GreaterThan ">" ]
132 , [ binary GreaterThanOrEqualTo ">=" ]
133 , [ unary Not "!" ]
134 , [ unary BitwiseNot "~" ]
135 , [ unary Negate "-" ]
136 , [ binary Multiply "*" ]
137 , [ binary Divide "/" ]
138 , [ binary Modulus "%" ]
139 , [ binary Concat "+" ]
140 , [ binary Add "+" ]
141 , [ binary Subtract "-" ]
142 , [ binary ShiftLeft "<<" ]
143 , [ binary ShiftRight ">>" ]
144 , [ binary ZeroFillShiftRight ">>>" ]
145 , [ binary EqualTo "===" ]
146 , [ binary NotEqualTo "!==" ]
147 , [ binary BitwiseAnd "&" ]
148 , [ binary BitwiseXor "^" ]
149 , [ binary BitwiseOr "|" ]
150 , [ binary And "&&" ]
151 , [ binary Or "||" ]
152 ]
154binderToJs :: String -> String -> Binder -> Gen String
155binderToJs varName done NullBinder = return done
156binderToJs varName done (StringBinder str) =
157 return $ "if (" ++ varName ++ " === \"" ++ str ++ "\") {" ++ done ++ " }"
158binderToJs varName done (NumberBinder num) =
159 return $ "if (" ++ varName ++ " === " ++ either show show num ++ ") {" ++ done ++ " }"
160binderToJs varName done (BooleanBinder True) =
161 return $ "if (" ++ varName ++ ") {" ++ done ++ " }"
162binderToJs varName done (BooleanBinder False) =
163 return $ "if (!" ++ varName ++ ") {" ++ done ++ " }"
164binderToJs varName done (VarBinder ident) =
165 return $ "var " ++ identToJs ident ++ " = " ++ varName ++ "; " ++ done
166binderToJs varName done (NullaryBinder ctor) =
167 return $ "if (" ++ varName ++ ".ctor === \"" ++ ctor ++ "\") { " ++ done ++ " }"
168binderToJs varName done (UnaryBinder ctor b) = do
169 value <- fresh
170 js <- binderToJs value done b
171 return $ "if (" ++ varName ++ ".ctor === \"" ++ ctor ++ "\") { " ++ "var " ++ value ++ " = " ++ varName ++ ".value; " ++ js ++ " }"
172binderToJs varName done (ObjectBinder bs) = go done bs
173 where
174 go done [] = return done
175 go done ((prop, binder):bs) = do
176 propVar <- fresh
177 done' <- go done bs
178 js <- binderToJs propVar done' binder
179 return $ "var " ++ propVar ++ " = " ++ varName ++ "." ++ prop ++ ";" ++ js
180binderToJs varName done (ArrayBinder bs rest) = do
181 js <- go done rest 0 bs
182 return $ "if (" ++ varName ++ ".length " ++ cmp ++ " " ++ show (length bs) ++ ") { " ++ js ++ " }"
183 where
184 cmp = maybe "===" (const ">=") rest
185 go done Nothing _ [] = return done
186 go done (Just binder) index [] = do
187 restVar <- fresh
188 js <- binderToJs restVar done binder
189 return $ "var " ++ restVar ++ " = " ++ varName ++ ".slice(" ++ show index ++ "); " ++ js
190 go done rest index (binder:bs) = do
191 elVar <- fresh
192 done' <- go done rest (index + 1) bs
193 js <- binderToJs elVar done' binder
194 return $ "var " ++ elVar ++ " = " ++ varName ++ "[" ++ show index ++ "]; " ++ js
195binderToJs varName done (NamedBinder ident binder) = do
196 js <- binderToJs varName done binder
197 return $ "var " ++ identToJs ident ++ " = " ++ varName ++ "; " ++ js
198binderToJs varName done (GuardedBinder cond binder) = binderToJs varName done' binder
199 where
200 done' = "if (" ++ valueToJs cond ++ ") { " ++ done ++ "}"
202objectPropertyToJs :: (String, Value) -> String
203objectPropertyToJs (key, value) = key ++ ": " ++ valueToJs value
205statementToJs :: Statement -> String
206statementToJs (VariableIntroduction ident value) = "var " ++ identToJs ident ++ " = " ++ valueToJs value
207statementToJs (Assignment target value) = identToJs target ++ " = " ++ valueToJs value
208statementToJs (While cond sts) = "while ("
209 ++ valueToJs cond ++ ") {"
210 ++ intercalate ";" (map statementToJs sts) ++ "}"
211statementToJs (For ident start end sts) = "for (" ++
212 identToJs ident ++ " = " ++ valueToJs start ++ ";"
213 ++ identToJs ident ++ " < " ++ valueToJs end ++ ";"
214 ++ identToJs ident ++ "++) {"
215 ++ intercalate ";" (map statementToJs sts) ++ "}"
216statementToJs (ForEach ident arr sts) = valueToJs arr
217 ++ ".forEach(function(" ++ identToJs ident ++ ") {"
218 ++ intercalate ";" (map statementToJs sts) ++ "})"
219statementToJs (If ifst) = ifStatementToJs ifst
220statementToJs (Return value) = "return " ++ valueToJs value
222ifStatementToJs :: IfStatement -> String
223ifStatementToJs (IfStatement cond thens elst) =
224 "if ("
225 ++ valueToJs cond ++ ") {"
226 ++ intercalate ";" (map statementToJs thens) ++ "}"
227 ++ maybe "" elseStatementToJs elst
229elseStatementToJs :: ElseStatement -> String
230elseStatementToJs (Else sts) = " else {" ++ intercalate ";" (map statementToJs sts) ++ "}"
231elseStatementToJs (ElseIf ifst) = " else " ++ ifStatementToJs ifst