b073973 · rowtype-yoga/purescript-native

examples/passing/Let.pursnew file+18

compare with golang

unifiedsplit

@@ -0,0 +1,18 @@

1+module Main where

2+

3+import Prelude

4+import Eff

5+

6+test1 x = let y = x + 1 in y

7+

8+test2 x y =

9+ let x' = x + 1 in

10+ let y' = y + 1 in

11+ x' + y'

12+

13+test3 x = let 1 = x in 2

14+

15+main = do

16+ Trace.print (test1 1)

17+ Trace.print (test2 1 2)

18+ Trace.print (test3 1)

purescript.cabal+1

@@ -35,6 +35,7 @@ library

35 Language.PureScript.Sugar.BindingGroups

36 Language.PureScript.Sugar.Operators

37 Language.PureScript.Sugar.TypeClasses

38+ Language.PureScript.Sugar.Let

38 Language.PureScript.CodeGen

39 Language.PureScript.CodeGen

39 Language.PureScript.CodeGen.Common

40 Language.PureScript.CodeGen.Common

40 Language.PureScript.CodeGen.Externs

41 Language.PureScript.CodeGen.Externs

src/Language/PureScript/Parser/Common.hs+2−1

@@ -49,7 +49,8 @@ reservedPsNames = [ "data"

49 , "true"

50 , "false"

51 , "until"

52−

52+ , "let"

53+ , "in"

53 ]

54 ]

54

55

55-- |

56-- |

src/Language/PureScript/Parser/Values.hs+15

@@ -82,6 +82,20 @@ parseIfThenElse = IfThenElse <$> (P.try (C.reserved "if") *> C.indented *> parse

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

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

84

85+parseLet :: P.Parsec String ParseState Value

86+parseLet = do

87+ C.reserved "let"

88+ C.indented

89+ binder <- parseBinder

90+ C.indented

91+ C.reservedOp "="

92+ C.indented

93+ value <- parseValue

94+ C.indented

95+ C.reserved "in"

96+ result <- parseValue

97+ return $ Let binder value result

98+

85parseValueAtom :: P.Parsec String ParseState Value

99parseValueAtom :: P.Parsec String ParseState Value

86parseValueAtom = P.choice

100parseValueAtom = P.choice

87 [ P.try parseNumericLiteral

101 [ P.try parseNumericLiteral

@@ -95,6 +109,7 @@ parseValueAtom = P.choice

95 , parseCase

109 , parseCase

96 , parseIfThenElse

110 , parseIfThenElse

97 , parseDo

111 , parseDo

112+ , parseLet

98 , Parens <$> C.parens parseValue ]

113 , Parens <$> C.parens parseValue ]

99

114

100parsePropertyUpdate :: P.Parsec String ParseState (String, Value)

115parsePropertyUpdate :: P.Parsec String ParseState (String, Value)

src/Language/PureScript/Sugar.hs+6−1

@@ -16,6 +16,7 @@

16module Language.PureScript.Sugar (desugar, module S) where

17

18import Control.Monad

19+import Control.Arrow ((>>>))

19

20

20import Language.PureScript.Declarations

21import Language.PureScript.Declarations

21

22

@@ -25,10 +26,13 @@ import Language.PureScript.Sugar.CaseDeclarations as S

25import Language.PureScript.Sugar.TypeDeclarations as S

26import Language.PureScript.Sugar.TypeDeclarations as S

26import Language.PureScript.Sugar.BindingGroups as S

27import Language.PureScript.Sugar.BindingGroups as S

27import Language.PureScript.Sugar.TypeClasses as S

28import Language.PureScript.Sugar.TypeClasses as S

29+import Language.PureScript.Sugar.Let as S

28

30

29-- |

31-- |

30-- The desugaring pipeline proceeds as follows:

32-- The desugaring pipeline proceeds as follows:

31--

33--

34+-- * Desugar let bindings

35+--

32-- * Introduce type synonyms for type class dictionaries

36-- * Introduce type synonyms for type class dictionaries

33--

37--

34-- * Rebracket user-defined binary operators

38-- * Rebracket user-defined binary operators

@@ -45,6 +49,7 @@ desugar :: [Module] -> Either String [Module]

45desugar = desugarTypeClasses

49desugar = desugarTypeClasses

46 >=> rebracket

50 >=> rebracket

47 >=> desugarDo

51 >=> desugarDo

52+ >=> desugarLetBindings

48− >=> desugarCasesModule

53+ >>> desugarCasesModule

49 >=> desugarTypeDeclarationsModule

54 >=> desugarTypeDeclarationsModule

50 >=> createBindingGroupsModule

55 >=> createBindingGroupsModule

src/Language/PureScript/Sugar/Let.hsnew file+32

@@ -0,0 +1,32 @@

1+-----------------------------------------------------------------------------

2+--

3+-- Module : Language.PureScript.Sugar.Let

4+-- Copyright : (c) Phil Freeman 2014

5+-- License : MIT

6+--

7+-- Maintainer : Phil Freeman <paf31@cantab.net>

8+-- Stability : experimental

9+-- Portability :

10+--

11+-- |

12+-- This module implements the desugaring pass which turns let bindings into function applications.

13+--

14+-----------------------------------------------------------------------------

15+

16+module Language.PureScript.Sugar.Let (

17+ desugarLetBindings

18+) where

19+

20+import Data.Generics (mkT, everywhere)

21+

22+import Language.PureScript.Values

23+import Language.PureScript.Declarations

24+

25+-- |

26+-- Turn let bindings into function applications

27+--

28+desugarLetBindings :: [Module] -> [Module]

29+desugarLetBindings = everywhere (mkT go)

30+ where

31+ go (Let binder value result) = Case [value] [([binder], Nothing, result)]

32+ go other = other

src/Language/PureScript/Values.hs+4

@@ -99,6 +99,10 @@ data Value

99 --

100 | TypedValue Bool Value Type

101 -- |

102+ -- A let binding

103+ --

104+ | Let Binder Value Value

105+ -- |

102 -- A do-notation block

106 -- A do-notation block

103 --

107 --

104 | Do [DoNotationElement]

108 | Do [DoNotationElement]