git.iko.soy/elk
on 501c607 help sign in
elk/src/Parse/Module.hs
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1module Parse.Module (header, headerAndImports, getModuleName) where
3import Control.Applicative ((<$>), (<*>))
4import Text.Parsec hiding (newline, spaces)
6import Parse.Helpers
7import qualified AST.Module as Module
8import qualified AST.Variable as Var
11getModuleName :: String -> Maybe String
12getModuleName source =
13 case iParse getModuleName source of
14 Right name -> Just name
15 Left _ -> Nothing
16 where
17 getModuleName =
18 do optional freshLine
19 (names, _) <- header
20 return (Module.nameToString names)
23headerAndImports :: IParser Module.HeaderAndImports
24headerAndImports =
25 do optional freshLine
26 (names, exports) <-
27 option (["Main"], Var.openListing) (header `followedBy` freshLine)
28 imports' <- imports
29 return $ Module.HeaderAndImports names exports imports'
32header :: IParser ([String], Var.Listing Var.Value)
33header =
34 do try (reserved "module")
35 whitespace
36 names <- dotSep1 capVar <?> "name of module"
37 whitespace
38 exports <- option Var.openListing (listing value)
39 whitespace <?> "reserved word 'where'"
40 reserved "where"
41 return (names, exports)
44imports :: IParser [(Module.Name, Module.ImportMethod)]
45imports =
46 many (import' `followedBy` freshLine)
49import' :: IParser (Module.Name, Module.ImportMethod)
50import' =
51 do try (reserved "import")
52 whitespace
53 names <- dotSep1 capVar
54 (,) names <$> method (Module.nameToString names)
55 where
56 method :: String -> IParser Module.ImportMethod
57 method defaultAlias =
58 Module.ImportMethod
59 <$> option (Just defaultAlias) (Just <$> as')
60 <*> option Var.closedListing exposing
62 as' :: IParser String
63 as' =
64 do try (whitespace >> reserved "as")
65 whitespace
66 capVar <?> "alias for module"
68 exposing :: IParser (Var.Listing Var.Value)
69 exposing =
70 do try (whitespace >> reserved "exposing")
71 whitespace
72 listing value
75listing :: IParser a -> IParser (Var.Listing a)
76listing item =
77 do try (whitespace >> char '(')
78 whitespace
79 listing <-
80 choice
81 [ const Var.openListing <$> string ".."
82 , Var.Listing <$> commaSep1 item <*> return False
83 ] <?> "listing of values (x,y,z)"
84 whitespace
85 char ')'
86 return listing
89value :: IParser Var.Value
90value =
91 val <|> tipe
92 where
93 val =
94 Var.Value <$> (lowVar <|> parens symOp)
96 tipe =
97 do name <- capVar
98 maybeCtors <- optionMaybe (listing capVar)
99 case maybeCtors of
100 Nothing -> return (Var.Alias name)
101 Just ctors -> return (Var.Union name ctors)