536281b · rowtype-yoga/purescript-native

git.iko.soy/rowtype-yoga/purescript-native

If-Then-Else expressions

commit536281bba91ed7ed8fe8a567d02cb246dbf45aa3 authorPhil Freeman <paf31@cantab.net> dateSat 26 Oct 2013, 17:04 (13 years ago) parent071d687

5 files changed+24

compare with golang

unifiedsplit

examples/Conditional.ps+5 src/PureScript/CodeGen/JS.hs+7 src/PureScript/Parser/Values.hs+6 src/PureScript/TypeChecker/Types.hs+5 src/PureScript/Values.hs+1

examples/Conditional.psnew file+5

@@ -0,0 +1,5 @@

1+fns = \f -> if f true then f else \x -> x

3+bin = \x -> if x && !x then x else x

5+not = \x -> if x then false else true

src/PureScript/CodeGen/JS.hs+7

@@ -63,6 +63,12 @@ literals = Pattern $ A.Kleisli match

6363 match (Var ident) = Just (identToJs ident)

6464 match _ = Nothing

6565

66+ifThenElse :: Pattern Value ((Value, Value), Value)

67+ifThenElse = Pattern $ A.Kleisli match

68+ where

69+ match (IfThenElse cond th el) = Just ((th, el), cond)

70+ match _ = Nothing

71+

6672accessor :: Pattern Value (String, Value)

6773accessor = Pattern $ A.Kleisli match

6874 where

@@ -116,6 +122,7 @@ valueToJs = fromMaybe (error "Incomplete pattern") . pattern matchValue

116122 , [ Wrap indexer $ \index val -> val ++ "[" ++ index ++ "]" ]

117123 , [ Wrap app $ \args val -> val ++ "(" ++ args ++ ")" ]

118124 , [ Split lam $ \args val -> "function (" ++ intercalate "," args ++ ") { return " ++ valueToJs val ++ "; }" ]

125+ , [ Wrap ifThenElse $ \(th, el) cond -> cond ++ " ? " ++ valueToJs th ++ " : " ++ valueToJs el ]

119126 , [ binary LessThan "<" ]

120127 , [ binary LessThanOrEqualTo "<=" ]

121128 , [ binary GreaterThan ">" ]

src/PureScript/Parser/Values.hs+6

@@ -74,6 +74,11 @@ parseCase = Case <$> (P.between (C.reserved "case") (C.indented *> C.reserved "o

7474parseCaseAlternative :: P.Parsec String P.Column (Binder, Value)

7575parseCaseAlternative = (,) <$> (parseGuardedBinder <* C.lexeme (P.string "->")) <*> parseValue

7676

77+parseIfThenElse :: P.Parsec String P.Column Value

78+parseIfThenElse = IfThenElse <$> (C.reserved "if" *> C.indented *> parseValue)

79+ <*> (C.indented *> C.reserved "then" *> C.indented *> parseValue)

80+ <*> (C.indented *> C.reserved "else" *> C.indented *> parseValue)

81+

7782parseBlock :: P.Parsec String P.Column Value

7883parseBlock = Block <$> (C.reserved "do" *> parseManyStatements)

7984

@@ -92,6 +97,7 @@ parseValueAtom = C.indented *> P.choice (map P.try

9297 , parseConstructor

9398 , parseBlock

9499 , parseCase

100+ , parseIfThenElse

95101 , C.parens parseValue ])

96102

97103parseValue :: P.Parsec String P.Column Value

src/PureScript/TypeChecker/Types.hs+5

@@ -266,6 +266,11 @@ typeConstraints m (Case val binders) = do

266266 ret <- fresh

267267 cs2 <- typeConstraintsForBinders m n1 ret binders

268268 return (cs1 ++ cs2, ret)

269+typeConstraints m (IfThenElse cond th el) = do

270+ (cs1, n1) <- typeConstraints m cond

271+ (cs2, n2) <- typeConstraints m th

272+ (cs3, n3) <- typeConstraints m el

273+ return (TypeConstraint n1 Boolean : TypeConstraint n2 (TUnknown n3) : cs1 ++ cs2 ++ cs3, n2)

269274typeConstraints m (TypedValue val poly@(PolyType idents ty)) = do

270275 kind <- kindOf poly

271276 guardWith ("Expected type of kind *, was " ++ show kind) $ kind == Star

src/PureScript/Values.hs+1

@@ -61,6 +61,7 @@ data Value

6161 | Abs [Ident] Value

6262 | App Value [Value]

6363 | Var Ident

64+ | IfThenElse Value Value Value

6465 | Block [Statement]

6566 | Constructor String

6667 | Case Value [(Binder, Value)]